Support for Business Process Flexibility in Service Compositions: An Evaluative Survey
---
paper_title: Process-Aware Information Systems: Bridging People and Software Through Process Technology

paper_content:

In the last 10 years, there has been an explosion in the number of technologies, standards, and tools to provide process support. The book provides a unified and comprehensive overview of the principles, techniques and technologies underlying the emerging discipline of process aware information systems engineering. It brings together contributions from leading experts in this fast-growing field. Each chapter ends with a collection of thought-provoking exercises, which also makes it ideal as a text book. The book closes with a list of resources including suggested readings as well as URLs of relevantstandardization bodies, initiatives, and consortia
---
paper_title: Artifact-Centric Business Process Models: Brief Survey of Research Results and Challenges

paper_content:

A data-centric approach to business process and workflow modeling has been emerging over the past several years. This short paper presents a structured framework for a class of data-centric business process models, which are based on "business artifacts". The paper provides a brief survey of research results on artifact-centric business process, and identifies a broad array of remaining research challenges.
---
paper_title: Enabling On-the-Fly Business Process Composition through an Event-Based Approach

paper_content:

Agility is a key characteristic for modern enterprises operating in a highly dynamic environment. The attainment of agility is a difficult issue involving all organizational aspects, such as business processes, information systems, personnel, organizational structure, etc. The ability to respond rapidly to changes by utilizing agile business processes is an important constituent of an agile enterprise. The focus of this paper is business process agility outlining the benefits of event-based business process modeling. To this end, an event-based approach is proposed enabling on-the-fly composition of business processes. The introduced approach adopts the concepts of complex event processing. A conceptual architecture for an information technology infrastructure supporting event-driven business process execution is also proposed.
---
paper_title: Business process management: A survey

paper_content:

Business Process Management (BPM) includes methods, techniques, and tools to support the design, enactment, management, and analysis of operational business processes. It can be considered as an extension of classical Workflow Management (WFM) systems and approaches. Although the practical relevance of BPM is undisputed, a clear definition of BPM and related acronyms such as BAM, BPA, and STP are missing. Moreover, a clear scientific foundation is missing. In this paper, we try to demystify the acronyms in this domain, describe the state-of-the-art technology, and argue that BPM could benefit from formal methods/languages (cf. Petri nets, process algebras, etc.).
---
paper_title: A declarative approach for flexible business processes management

paper_content:

Management of dynamic processes in an important issue in rapidly changing organizations. Workflow management systems are systems that use detailed process models to drive the business processes. Current business process modelling languages and models are of imperative nature – they strictly prescribe how to work. Systems that allow users to maneuver within the process model or even change the model while working are considered to be the most suitable for dynamic processes management. However, in many companies it is not realistic to expect that end-users are able to change their processes. Moreover, the imperative nature of these languages forces designer to over-specify processes, which results in frequent changes. We propose a fundamental paradigm shift for flexible process management and propose a more declarative approach. Declarative models specify what should be done without specifying how it should be done. We propose the ConDec language for modelling and enacting dynamic business processes. ConDec is based on temporal logic rather than some imperative process modelling language.
---
paper_title: Flexibility of data-driven process structures

paper_content:

The coordination of complex process structures is a fundamental task for enterprises, such as in the automotive industry. Usually, such process structures consist of several (sub-)processes whose execution must be coordinated and synchronized. Effecting this manually is both ineffective and error-prone. However, we can benefit from the fact that these processes are correlated with product structures in many application domains, such as product engineering. Specifically, we can utilize the assembly of a complex real object, such as a car consisting of different mechanical, electrical or electronic subcomponents. Each sub-component has related design or testing processes, which have to be executed within an overall process structure according to the product structure. Our goal is to enable product-driven (i.e., data-driven) process modeling, execution and adaptation. We show the necessity of considering the product life cycle and the role of processes, which are triggering state transitions within the product life cycle. This paper discusses important issues related to the design, enactment and change of data-driven process structures. Our considerations are based on several case studies we conducted for engineering processes in the automotive industry.
---
paper_title: Dynamic Routing as paradigm for decentralized flexible process management

paper_content:

Since companies face continuously changing business processes, centralized process repositories and execution engines have been integrated into the heart of enterprise systems. These systems are then able to support repetitive processes. In order to extend the reach of process orientation into more collaborative settings, employees must be given the possibility to adapt and refine the processes to their individual needs. Personalized process templates are applied to tasks and running process instances are subject to massive changes by the participants. These flexible processes require for process management infrastructures of a more peer to peer style. We argue that the concept of Dynamic Routing is a valuable paradigm for supporting highly flexible processes. We identified three patterns for Dynamic Routing and sketch future enterprise system architectures implementing these. We present two case studies where dynamically routed interactions are at the center of attention.
---
paper_title: Process Flexibility: a Survey of Contemporary Approaches

paper_content:

Business processes provide a means of coordinating interactions between workers and organisations in a structured way. However the dynamic nature of the modern business environment means these processes are subject to a increasingly wide range of variations and must demonstrate flexible approaches to dealing with these variations if they are to remain viable. The challenge is to provide flexibility and offer process support at the same time. Many approaches have been proposed in literature and some of these approaches have been implemented in flexible workflow management systems. However, a comprehensive overview of the various approaches has been missing. In this paper, we take a deeper look into the various ways in which flexibility can be achieved and we propose an extensive taxonomy of flexibility. This taxonomy is subsequently used to evaluate a selection of systems and to discuss how the various forms of flexibility fit together.
---
paper_title: Conditional workflow management: A survey and analysis

paper_content:

Workflows form the essential part of the process execution both in a single machine and in distributed environments. Although providing conditional structures is not mandatory for a workflow management system, support for conditional workflows is very important in terms of error handling, flexibility and robustness. Several of the existing workflow management systems already support conditional structures via use of different constructs. In this paper, we study the most widely used workflow management systems and their support for conditional structures such as if, switch, and while. We compare implementation of common conditional structures using each of these workflow management systems via case studies, and discuss capabilities of each system.
---
paper_title: The Rise of Web Service Ecosystems

paper_content:

The convergence of Internet marketplaces and service-oriented architectures has spurred the growth of Web service ecosystems. This paper articulates a vision for Web service ecosystems, discusses early manifestations of this vision, and presents a unifying architecture to support the emergence of larger and more sophisticated ecosystems
---
paper_title: Beyond workflow management: product-driven case handling

paper_content:

In the last decade, workflow technology has become one of the building blocks for realizing enterprise information systems. Unfortunately, the application of contemporary workflow management systems is limited to well-defined and well-controlled environments. In practice, workflow technology often fails because of limited flexibility. We advocate a paradigm shift to overcome this problem: Workflows should not be driven by pre-specified control-flows but by the products they generate. This paper presents the software package FLOWer which fully supports this paradigm shift.
---
paper_title: Case handling: a new paradigm for business process support

paper_content:

Case handling is a new paradigm for supporting flexible and knowledge intensive business processes. It is strongly based on data as the typical product of these processes. Unlike workflow management, which uses predefined process control structures to determine what should be done during a workflow process, case handling focuses on what can be done to achieve a business goal. In case handling, the knowledge worker in charge of a particular case actively decides on how the goal of that case is reached, and the role of a case handling system is assisting rather than guiding her in doing so. In this paper, case handling is introduced as a new paradigm for supporting flexible business processes. It is motivated by comparing it to workflow management as the traditional way to support business processes. The main entities of case handling systems are identified and classified in a meta model. Finally, the basic functionality and usage of a case handling system is illustrated by an example.
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paper_title: A Survey on the Flexibility Requirements Related to Business Processes and Modeling Artifacts

paper_content:

In competitive and evolving environments only organizations which can manage complexity and can respond to rapid change in an informed manner can gain a competitive advantage During the early 90's, workflow technologies offered a transversal integration capacity to the enterprise applications. Today, to "integrate " enterprise applications -and the activities they support- into business processes is not sufficient. The architecture of this integration should also be flexible. Enterprise requirements highlight flexible and adaptive processes whose execution can evolve (i) according to situations that cannot always be prescribed, and/or (ii) according to business changes (organizational, process improvement, strategic ...). More recent works highlight requirements in term of flexible and adaptive workflows, whose execution can evolve according to situations that cannot always be prescribed. This paper presents the state of the art for flexible business process management systems and criteria for comparing them.
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paper_title: A Survey of Comparative Business Process Modeling Approaches

paper_content:

There has been a huge influx of business process modeling langu ages as business process management (BPM) and process-aware information systems continue to expand into various business domains. The origins of process modeling languages are quite diverse, although two dominant approaches can be observed; one based on graphical models, and the other based on rule specifications. However, at this time, there is no report in literature that specifically targets a comparative analysis of these two approaches, on aspects such as the relative areas of application, power of expression, and limitations. In this paper we have attempted to address this question. We will present both a survey of the two approaches as well as a critical and comparative analysis.
---
paper_title: Product Based Workflow Support: Dynamic Workflow Execution

paper_content:

Product Based Workflow Design (PBWD) is a successful new approach to workflow process support. A description of the product, the Product Data Model (PDM), is central to this approach. While other research so far has focused on deriving a process model from the PDM, this paper presents a way to directly execute the PDM. This leads to a more dynamic and flexible support for the workflow process.
---
paper_title: Life After BPEL

paper_content:

The Business Process Execution Language for Web Services (BPEL) has emerged as a standard for specifying and executing processes. It is supported by vendors such as IBM and Microsoft and positioned as the “process language of the Internet”. This paper provides a critical analysis of BPEL based on the so-called workflow patterns. It also discusses the need for languages like BPEL. Finally, the paper addresses several challenges not directly addressed by BPEL but highly relevant to the support of web services.
---
paper_title: Adeptflex—Supporting Dynamic Changes of Workflows Without Losing Control

paper_content:

Today‘s workflow management systems (WFMS_s) are only applicable in a secure and safe manner if the business process (BP) to be supported is well-structured and there is no need for ad hoc deviations at run-time. As only few BPs are static in this sense, this significantly limits the applicability of current workflow (WF) technology. On the other hand, to support dynamic deviations from premodeled task sequences must not mean that the responsibility for the avoidance of consistency problems and run-time errors is now completely shifted to the (naive) end user. In this paper we present a formal foundation for the support of dynamic structural changes of running WF instances. Based upon a formal WF model (ADEPT), we define a complete and minimal set of change operations (ADEPT_flex) that support users in modifying the structure of a running WF, while maintaining its (structural) correctness and consistency. The correctness properties defined by ADEPT are used to determine whether a specific change can be applied to a given WF instance or not. If these properties are violated, the change is either rejected or the correctness must be restored by handling the exceptions resulting from the change. We discuss basic issues with respect to the management of changes and the undoing of temporary changes at the instance level. Recently we have started the design and implementation of ADEPT_workflow, the ADEPT workflow engine, which will make use of the change facilities presented in this paper.
---
paper_title: Enabling On-the-Fly Business Process Composition through an Event-Based Approach

paper_content:

Agility is a key characteristic for modern enterprises operating in a highly dynamic environment. The attainment of agility is a difficult issue involving all organizational aspects, such as business processes, information systems, personnel, organizational structure, etc. The ability to respond rapidly to changes by utilizing agile business processes is an important constituent of an agile enterprise. The focus of this paper is business process agility outlining the benefits of event-based business process modeling. To this end, an event-based approach is proposed enabling on-the-fly composition of business processes. The introduced approach adopts the concepts of complex event processing. A conceptual architecture for an information technology infrastructure supporting event-driven business process execution is also proposed.
---
paper_title: A declarative approach for flexible business processes management

paper_content:

Management of dynamic processes in an important issue in rapidly changing organizations. Workflow management systems are systems that use detailed process models to drive the business processes. Current business process modelling languages and models are of imperative nature – they strictly prescribe how to work. Systems that allow users to maneuver within the process model or even change the model while working are considered to be the most suitable for dynamic processes management. However, in many companies it is not realistic to expect that end-users are able to change their processes. Moreover, the imperative nature of these languages forces designer to over-specify processes, which results in frequent changes. We propose a fundamental paradigm shift for flexible process management and propose a more declarative approach. Declarative models specify what should be done without specifying how it should be done. We propose the ConDec language for modelling and enacting dynamic business processes. ConDec is based on temporal logic rather than some imperative process modelling language.
---
paper_title: Dynamic Routing as paradigm for decentralized flexible process management

paper_content:

Since companies face continuously changing business processes, centralized process repositories and execution engines have been integrated into the heart of enterprise systems. These systems are then able to support repetitive processes. In order to extend the reach of process orientation into more collaborative settings, employees must be given the possibility to adapt and refine the processes to their individual needs. Personalized process templates are applied to tasks and running process instances are subject to massive changes by the participants. These flexible processes require for process management infrastructures of a more peer to peer style. We argue that the concept of Dynamic Routing is a valuable paradigm for supporting highly flexible processes. We identified three patterns for Dynamic Routing and sketch future enterprise system architectures implementing these. We present two case studies where dynamically routed interactions are at the center of attention.
---
paper_title: DECLARE: Full Support for Loosely-Structured Processes

paper_content:

Traditional workflow management systems (WFMSs) are not flexible enough to support loosely-structured processes. Furthermore, flexibility in contemporary WFMSs usually comes at a certain cost, such as lack of support for users, lack of methods for model analysis, lack of methods for analysis of past executions, etc. DECLARE is a proto-type of a WFMS that uses a constraint-based process modeling language for the development of declarative models describing loosely-structured processes. In this paper we show how DECLARE can support loosely-structured processes without sacrificing important WFMSs features like user support, model verification, analysis of past executions, changing models at run-time, etc.
---
paper_title: DecSerFlow: Towards a Truly Declarative Service Flow Language

paper_content:

The need for process support in the context of web services has triggered the development of many languages, systems, and standards. Industry has been developing software solutions and proposing standards such as BPEL, while researchers have been advocating the use of formal methods such as Petri nets and π-calculus. The languages developed for service flows, i.e., process specification languages for web services, have adopted many concepts from classical workflow management systems. As a result, these languages are rather procedural and this does not fit well with the autonomous nature of services. Therefore, we propose DecSerFlow as a Declarative Service Flow Language. DecSerFlow can be used to specify, enact, and monitor service flows. The language is extendible (i.e., constructs can be added without changing the engine or semantical basis) and can be used to enforce or to check the conformance of service flows. Although the language has an appealing graphical representation, it is grounded in temporal logic.
---
paper_title: Worklets: A Service-Oriented Implementation of Dynamic Flexibility in Workflows

paper_content:

A yoke for a hookes universal joint, formed of a lightweight metal and having a base, two limbs extending axially from the base, the limbs having reinforcing flanges at least adjacent to the base and the thickness of the base being such that the limbs and base form a generally U-shaped structure of high rigidity.
---
paper_title: Patterns of Business Rules to Enable Agile Business Processes

paper_content:

A problem of today's standard business process (BP) automation systems is that they are too rigid to cope with changing business demands, especially for long running BPs. A solution to overcome this problem is to combine BPs with business rules (BR). State of the art BP automation systems are based on Web service (WS) technology and use WS composition languages, for example BPEL, for abstract and executable BPs. On the other hand, most of today's implementations use BRs mostly to make calculations and to adapt simple decisions to business users without full integration into a BP automation system. We will show that BP execution and BR functionality can be integrated properly in a standard service oriented architecture. This finding will be applied in a new approach of configuring BPs through using BRs. The assumption is that if one considers BRs already while modeling a BP, more advanced BP aspects like decisions, data constraints and control flow can be made agile and adaptive during run-time. We present multiple solutions demonstrating how BRs can be used to obtain different aspects ofBP agility. Described as BP Modeling Patterns, our solutions give insight on how agile BPs can be implemented with current BP automation technology. We implemented them using IBM WebSphere integration developer and IBM WebSphere process server.
---
paper_title: Merging overlapping orchestrations: an application to the Bronze Standard medical application

paper_content:

Merging orchestrations is a crucial issue in the development process of service-based applications. However, merging orchestrations with overlaps is a manual and tedious process today. In this paper, we present a case-study on the Bronze-Standard, a medical imaging application built from Web-Service based orchestrations. We introduce the OMSM, an orchestration model supporting merging, that we designed to assist this process. Through a detailed analysis of the use-case, we show how our model helps the developer to obtain a proper composition of the application. There is still room for generalizing the approach to a broader set of orchestrations as discussed.
---
paper_title: On-the-Fly Verification of Linear Temporal Logic

paper_content:

In this paper we present two new practical and pragmatic algorithms for solving the two key on-the-fly model-checking problems for linear temporal logic: on demand construction of an automaton for a temporal logic formula; and on-the-fly checking for whether the automata resulting from the product of the program and the property is empty.
---
paper_title: Beyond workflow management: product-driven case handling

paper_content:

In the last decade, workflow technology has become one of the building blocks for realizing enterprise information systems. Unfortunately, the application of contemporary workflow management systems is limited to well-defined and well-controlled environments. In practice, workflow technology often fails because of limited flexibility. We advocate a paradigm shift to overcome this problem: Workflows should not be driven by pre-specified control-flows but by the products they generate. This paper presents the software package FLOWer which fully supports this paradigm shift.
---
paper_title: Case handling: a new paradigm for business process support

paper_content:

Case handling is a new paradigm for supporting flexible and knowledge intensive business processes. It is strongly based on data as the typical product of these processes. Unlike workflow management, which uses predefined process control structures to determine what should be done during a workflow process, case handling focuses on what can be done to achieve a business goal. In case handling, the knowledge worker in charge of a particular case actively decides on how the goal of that case is reached, and the role of a case handling system is assisting rather than guiding her in doing so. In this paper, case handling is introduced as a new paradigm for supporting flexible business processes. It is motivated by comparing it to workflow management as the traditional way to support business processes. The main entities of case handling systems are identified and classified in a meta model. Finally, the basic functionality and usage of a case handling system is illustrated by an example.
---
paper_title: Semantic orchestrations merging - Towards Composition of Overlapping Orchestrations

paper_content:

Service oriented architectures foster evolution of enterprise information systems by supporting loose coupling and easy composition of services. Unfortunately, current approaches to service composition are inapplicable to services that share subservices or data. In this paper, we define overlapping orchestrations, analyse the problems that they pose to existing composition approaches and propose orchestration merging, a novel, interactive approach to composition of overlapping orchestrations based on their semantic.
---
paper_title: Product Based Workflow Support: Dynamic Workflow Execution

paper_content:

Product Based Workflow Design (PBWD) is a successful new approach to workflow process support. A description of the product, the Product Data Model (PDM), is central to this approach. While other research so far has focused on deriving a process model from the PDM, this paper presents a way to directly execute the PDM. This leads to a more dynamic and flexible support for the workflow process.
---
paper_title: Constraint-based workflow models: Change made easy

paper_content:

The degree of flexibility of workflow management systems heavily influences the way business processes are executed. Constraint-based models are considered to be more flexible than traditional models because of their semantics: everything that does not violate constraints is allowed. Although constraint-based models are flexible, changes to process definitions might be needed to comply with evolving business domains and exceptional situations. Flexibility can be increased by run-time support for dynamic changes - transferring instances to a new model - and ad-hoc changes - changing the process definition for one instance. In this paper we propose a general framework for a constraint-based process modeling language and its implementation. Our approach supports both ad-hoc and dynamic change, and the transfer of instances can be done easier than in traditional approaches.
---
paper_title: Hybrid web service composition: business processes meet business rules

paper_content:

Over the last few years several process-based web service composition languages have erged, such as BPEL4WS and BPML. These languages define the composition on the basis of a process that specifies the control and data flow among the services to be composed. In this approach, the whole business logic underlying the composition including business policies and constraints is coded as a monolithic block. As a result, business rules are hard to change without affecting the core composition logic. In this paper, we propose a hybrid composition approach: The composition logic is broken down into a core part (the process) and several well-modularized business rules that exist and evolve independently. We also discuss two alternative technologies for implenting business rules in encapsulated units, using aspects and a rule-based engine. Our approach allows for a more modular and flexible web service composition.
---
paper_title: Process Flexibility: a Survey of Contemporary Approaches

paper_content:

Business processes provide a means of coordinating interactions between workers and organisations in a structured way. However the dynamic nature of the modern business environment means these processes are subject to a increasingly wide range of variations and must demonstrate flexible approaches to dealing with these variations if they are to remain viable. The challenge is to provide flexibility and offer process support at the same time. Many approaches have been proposed in literature and some of these approaches have been implemented in flexible workflow management systems. However, a comprehensive overview of the various approaches has been missing. In this paper, we take a deeper look into the various ways in which flexibility can be achieved and we propose an extensive taxonomy of flexibility. This taxonomy is subsequently used to evaluate a selection of systems and to discuss how the various forms of flexibility fit together.
---
paper_title: Semantic orchestrations merging - Towards Composition of Overlapping Orchestrations

paper_content:

Service oriented architectures foster evolution of enterprise information systems by supporting loose coupling and easy composition of services. Unfortunately, current approaches to service composition are inapplicable to services that share subservices or data. In this paper, we define overlapping orchestrations, analyse the problems that they pose to existing composition approaches and propose orchestration merging, a novel, interactive approach to composition of overlapping orchestrations based on their semantic.
---
paper_title: Dynamic Support for BPEL Process Instance Adaptation

paper_content:

Rapidly changing market conditions and IT systems are forcing companies to adapt their business processes more dynamically than in the past. Most current commercial BPMS products lack the full capability to support changing processes. To address this challenge, we discuss three aspects of dynamic adaptation in a BPM system: model-level, instance-level, and runtime environment changes. We focus on analyzing the patterns of the instance-level navigation changes, including the preconditions, actions and consequences of each change. Based on this analysis, we propose a system design for the runtime environment to support dynamic instance-level changes. We have implemented a prototype of such a system with the motivating scenarios to demonstrate the usefulness of our proposal.
---
paper_title: Enabling On-the-Fly Business Process Composition through an Event-Based Approach

paper_content:

Agility is a key characteristic for modern enterprises operating in a highly dynamic environment. The attainment of agility is a difficult issue involving all organizational aspects, such as business processes, information systems, personnel, organizational structure, etc. The ability to respond rapidly to changes by utilizing agile business processes is an important constituent of an agile enterprise. The focus of this paper is business process agility outlining the benefits of event-based business process modeling. To this end, an event-based approach is proposed enabling on-the-fly composition of business processes. The introduced approach adopts the concepts of complex event processing. A conceptual architecture for an information technology infrastructure supporting event-driven business process execution is also proposed.
---
paper_title: A declarative approach for flexible business processes management

paper_content:

Management of dynamic processes in an important issue in rapidly changing organizations. Workflow management systems are systems that use detailed process models to drive the business processes. Current business process modelling languages and models are of imperative nature – they strictly prescribe how to work. Systems that allow users to maneuver within the process model or even change the model while working are considered to be the most suitable for dynamic processes management. However, in many companies it is not realistic to expect that end-users are able to change their processes. Moreover, the imperative nature of these languages forces designer to over-specify processes, which results in frequent changes. We propose a fundamental paradigm shift for flexible process management and propose a more declarative approach. Declarative models specify what should be done without specifying how it should be done. We propose the ConDec language for modelling and enacting dynamic business processes. ConDec is based on temporal logic rather than some imperative process modelling language.
---
paper_title: Case Handling Systems as Product Based Workflow Design Support

paper_content:

Case handling systems offer a solution to the lack of flexibility and adaptability in workflow management systems. Because they are data driven they potentially provide good support for Product Based Workflow Design (PBWD). In this paper we investigate to which degree current case handling systems (FLOWer and Activity Manager) are able to support PBWD. This is done by elaborating the design process of a case from industry in both systems. From this evaluation we concluded that current case handling systems are not yet completely ready for supporting PBWD. Therefore, we recognize that better tool support is needed to make PBWD more suitable for practical use.
---
paper_title: Dynamic Routing as paradigm for decentralized flexible process management

paper_content:

Since companies face continuously changing business processes, centralized process repositories and execution engines have been integrated into the heart of enterprise systems. These systems are then able to support repetitive processes. In order to extend the reach of process orientation into more collaborative settings, employees must be given the possibility to adapt and refine the processes to their individual needs. Personalized process templates are applied to tasks and running process instances are subject to massive changes by the participants. These flexible processes require for process management infrastructures of a more peer to peer style. We argue that the concept of Dynamic Routing is a valuable paradigm for supporting highly flexible processes. We identified three patterns for Dynamic Routing and sketch future enterprise system architectures implementing these. We present two case studies where dynamically routed interactions are at the center of attention.
---
paper_title: Dynamic workflow schema evolution based on workflow type versioning and workflow migration

paper_content:

An important yet open problem in workflow management is the evolution of workflow schemas, i.e., the creation, deletion and modification of workflow types in such a way that the schema remains correct. This problem is aggravated when instances of modified workflow types are active at the time of modification because any workflow instance has to conform to the definition of its type. The paper presents a framework for dynamic workflow schema evolution that is based on workflow type versioning and workflow migration. Workflow types can be versioned, and a new version can be derived from an existing one by applying modification operations. Workflow type versions allow us to handle active instances in an elegant way whenever a schema is modified. If possible, an affected workflow instance is migrated to the new version of its type. Otherwise, it continues to execute under its old type. We introduce correctness criteria that must be met by workflow schemas and workflow schema modification operations. We also define under which conditions the migration of workflow instances to new workflow type versions is allowed.
---
paper_title: DecSerFlow: Towards a Truly Declarative Service Flow Language

paper_content:

The need for process support in the context of web services has triggered the development of many languages, systems, and standards. Industry has been developing software solutions and proposing standards such as BPEL, while researchers have been advocating the use of formal methods such as Petri nets and π-calculus. The languages developed for service flows, i.e., process specification languages for web services, have adopted many concepts from classical workflow management systems. As a result, these languages are rather procedural and this does not fit well with the autonomous nature of services. Therefore, we propose DecSerFlow as a Declarative Service Flow Language. DecSerFlow can be used to specify, enact, and monitor service flows. The language is extendible (i.e., constructs can be added without changing the engine or semantical basis) and can be used to enforce or to check the conformance of service flows. Although the language has an appealing graphical representation, it is grounded in temporal logic.
---
paper_title: Worklets: A Service-Oriented Implementation of Dynamic Flexibility in Workflows

paper_content:

A yoke for a hookes universal joint, formed of a lightweight metal and having a base, two limbs extending axially from the base, the limbs having reinforcing flanges at least adjacent to the base and the thickness of the base being such that the limbs and base form a generally U-shaped structure of high rigidity.
---
paper_title: Patterns of Business Rules to Enable Agile Business Processes

paper_content:

A problem of today's standard business process (BP) automation systems is that they are too rigid to cope with changing business demands, especially for long running BPs. A solution to overcome this problem is to combine BPs with business rules (BR). State of the art BP automation systems are based on Web service (WS) technology and use WS composition languages, for example BPEL, for abstract and executable BPs. On the other hand, most of today's implementations use BRs mostly to make calculations and to adapt simple decisions to business users without full integration into a BP automation system. We will show that BP execution and BR functionality can be integrated properly in a standard service oriented architecture. This finding will be applied in a new approach of configuring BPs through using BRs. The assumption is that if one considers BRs already while modeling a BP, more advanced BP aspects like decisions, data constraints and control flow can be made agile and adaptive during run-time. We present multiple solutions demonstrating how BRs can be used to obtain different aspects ofBP agility. Described as BP Modeling Patterns, our solutions give insight on how agile BPs can be implemented with current BP automation technology. We implemented them using IBM WebSphere integration developer and IBM WebSphere process server.
---
paper_title: Beyond workflow management: product-driven case handling

paper_content:

In the last decade, workflow technology has become one of the building blocks for realizing enterprise information systems. Unfortunately, the application of contemporary workflow management systems is limited to well-defined and well-controlled environments. In practice, workflow technology often fails because of limited flexibility. We advocate a paradigm shift to overcome this problem: Workflows should not be driven by pre-specified control-flows but by the products they generate. This paper presents the software package FLOWer which fully supports this paradigm shift.
---
paper_title: Case handling: a new paradigm for business process support

paper_content:

Case handling is a new paradigm for supporting flexible and knowledge intensive business processes. It is strongly based on data as the typical product of these processes. Unlike workflow management, which uses predefined process control structures to determine what should be done during a workflow process, case handling focuses on what can be done to achieve a business goal. In case handling, the knowledge worker in charge of a particular case actively decides on how the goal of that case is reached, and the role of a case handling system is assisting rather than guiding her in doing so. In this paper, case handling is introduced as a new paradigm for supporting flexible business processes. It is motivated by comparing it to workflow management as the traditional way to support business processes. The main entities of case handling systems are identified and classified in a meta model. Finally, the basic functionality and usage of a case handling system is illustrated by an example.
---
paper_title: Product Based Workflow Support: Dynamic Workflow Execution

paper_content:

Product Based Workflow Design (PBWD) is a successful new approach to workflow process support. A description of the product, the Product Data Model (PDM), is central to this approach. While other research so far has focused on deriving a process model from the PDM, this paper presents a way to directly execute the PDM. This leads to a more dynamic and flexible support for the workflow process.
---
paper_title: Constraint-based workflow models: Change made easy

paper_content:

The degree of flexibility of workflow management systems heavily influences the way business processes are executed. Constraint-based models are considered to be more flexible than traditional models because of their semantics: everything that does not violate constraints is allowed. Although constraint-based models are flexible, changes to process definitions might be needed to comply with evolving business domains and exceptional situations. Flexibility can be increased by run-time support for dynamic changes - transferring instances to a new model - and ad-hoc changes - changing the process definition for one instance. In this paper we propose a general framework for a constraint-based process modeling language and its implementation. Our approach supports both ad-hoc and dynamic change, and the transfer of instances can be done easier than in traditional approaches.
---
paper_title: Hybrid web service composition: business processes meet business rules

paper_content:

Over the last few years several process-based web service composition languages have erged, such as BPEL4WS and BPML. These languages define the composition on the basis of a process that specifies the control and data flow among the services to be composed. In this approach, the whole business logic underlying the composition including business policies and constraints is coded as a monolithic block. As a result, business rules are hard to change without affecting the core composition logic. In this paper, we propose a hybrid composition approach: The composition logic is broken down into a core part (the process) and several well-modularized business rules that exist and evolve independently. We also discuss two alternative technologies for implenting business rules in encapsulated units, using aspects and a rule-based engine. Our approach allows for a more modular and flexible web service composition.
---
paper_title: Change Patterns and Change Support Features in Process-Aware Information Systems

paper_content:

A high voltage and high energy device for storing energy, comprising storage elements (4) disposed in concentric ring arrangements on insulating separating elements (5), the storage elements of one ring arrangement being connected by one of their ends to the storage elements of the preceding ring arrangement, and by their other end to the storage elements of the following ring arrangement, the assembly being mounted on a core of hard insulating material provided with a central bore and being embedded in a coating of semi-flexible material.
---
paper_title: Case handling: a new paradigm for business process support

paper_content:

Case handling is a new paradigm for supporting flexible and knowledge intensive business processes. It is strongly based on data as the typical product of these processes. Unlike workflow management, which uses predefined process control structures to determine what should be done during a workflow process, case handling focuses on what can be done to achieve a business goal. In case handling, the knowledge worker in charge of a particular case actively decides on how the goal of that case is reached, and the role of a case handling system is assisting rather than guiding her in doing so. In this paper, case handling is introduced as a new paradigm for supporting flexible business processes. It is motivated by comparing it to workflow management as the traditional way to support business processes. The main entities of case handling systems are identified and classified in a meta model. Finally, the basic functionality and usage of a case handling system is illustrated by an example.
---
paper_title: Enabling On-the-Fly Business Process Composition through an Event-Based Approach

paper_content:

Agility is a key characteristic for modern enterprises operating in a highly dynamic environment. The attainment of agility is a difficult issue involving all organizational aspects, such as business processes, information systems, personnel, organizational structure, etc. The ability to respond rapidly to changes by utilizing agile business processes is an important constituent of an agile enterprise. The focus of this paper is business process agility outlining the benefits of event-based business process modeling. To this end, an event-based approach is proposed enabling on-the-fly composition of business processes. The introduced approach adopts the concepts of complex event processing. A conceptual architecture for an information technology infrastructure supporting event-driven business process execution is also proposed.
---
paper_title: Dynamic Routing as paradigm for decentralized flexible process management

paper_content:

Since companies face continuously changing business processes, centralized process repositories and execution engines have been integrated into the heart of enterprise systems. These systems are then able to support repetitive processes. In order to extend the reach of process orientation into more collaborative settings, employees must be given the possibility to adapt and refine the processes to their individual needs. Personalized process templates are applied to tasks and running process instances are subject to massive changes by the participants. These flexible processes require for process management infrastructures of a more peer to peer style. We argue that the concept of Dynamic Routing is a valuable paradigm for supporting highly flexible processes. We identified three patterns for Dynamic Routing and sketch future enterprise system architectures implementing these. We present two case studies where dynamically routed interactions are at the center of attention.
---
paper_title: Worklets: A Service-Oriented Implementation of Dynamic Flexibility in Workflows

paper_content:

A yoke for a hookes universal joint, formed of a lightweight metal and having a base, two limbs extending axially from the base, the limbs having reinforcing flanges at least adjacent to the base and the thickness of the base being such that the limbs and base form a generally U-shaped structure of high rigidity.
---
paper_title: Patterns of Business Rules to Enable Agile Business Processes

paper_content:

A problem of today's standard business process (BP) automation systems is that they are too rigid to cope with changing business demands, especially for long running BPs. A solution to overcome this problem is to combine BPs with business rules (BR). State of the art BP automation systems are based on Web service (WS) technology and use WS composition languages, for example BPEL, for abstract and executable BPs. On the other hand, most of today's implementations use BRs mostly to make calculations and to adapt simple decisions to business users without full integration into a BP automation system. We will show that BP execution and BR functionality can be integrated properly in a standard service oriented architecture. This finding will be applied in a new approach of configuring BPs through using BRs. The assumption is that if one considers BRs already while modeling a BP, more advanced BP aspects like decisions, data constraints and control flow can be made agile and adaptive during run-time. We present multiple solutions demonstrating how BRs can be used to obtain different aspects ofBP agility. Described as BP Modeling Patterns, our solutions give insight on how agile BPs can be implemented with current BP automation technology. We implemented them using IBM WebSphere integration developer and IBM WebSphere process server.
---
paper_title: Beyond workflow management: product-driven case handling

paper_content:

In the last decade, workflow technology has become one of the building blocks for realizing enterprise information systems. Unfortunately, the application of contemporary workflow management systems is limited to well-defined and well-controlled environments. In practice, workflow technology often fails because of limited flexibility. We advocate a paradigm shift to overcome this problem: Workflows should not be driven by pre-specified control-flows but by the products they generate. This paper presents the software package FLOWer which fully supports this paradigm shift.
---
paper_title: Constraint-based workflow models: Change made easy

paper_content:

The degree of flexibility of workflow management systems heavily influences the way business processes are executed. Constraint-based models are considered to be more flexible than traditional models because of their semantics: everything that does not violate constraints is allowed. Although constraint-based models are flexible, changes to process definitions might be needed to comply with evolving business domains and exceptional situations. Flexibility can be increased by run-time support for dynamic changes - transferring instances to a new model - and ad-hoc changes - changing the process definition for one instance. In this paper we propose a general framework for a constraint-based process modeling language and its implementation. Our approach supports both ad-hoc and dynamic change, and the transfer of instances can be done easier than in traditional approaches.
---
paper_title: Hybrid web service composition: business processes meet business rules

paper_content:

Over the last few years several process-based web service composition languages have erged, such as BPEL4WS and BPML. These languages define the composition on the basis of a process that specifies the control and data flow among the services to be composed. In this approach, the whole business logic underlying the composition including business policies and constraints is coded as a monolithic block. As a result, business rules are hard to change without affecting the core composition logic. In this paper, we propose a hybrid composition approach: The composition logic is broken down into a core part (the process) and several well-modularized business rules that exist and evolve independently. We also discuss two alternative technologies for implenting business rules in encapsulated units, using aspects and a rule-based engine. Our approach allows for a more modular and flexible web service composition.
---
paper_title: Enabling On-the-Fly Business Process Composition through an Event-Based Approach

paper_content:

Agility is a key characteristic for modern enterprises operating in a highly dynamic environment. The attainment of agility is a difficult issue involving all organizational aspects, such as business processes, information systems, personnel, organizational structure, etc. The ability to respond rapidly to changes by utilizing agile business processes is an important constituent of an agile enterprise. The focus of this paper is business process agility outlining the benefits of event-based business process modeling. To this end, an event-based approach is proposed enabling on-the-fly composition of business processes. The introduced approach adopts the concepts of complex event processing. A conceptual architecture for an information technology infrastructure supporting event-driven business process execution is also proposed.
---
paper_title: PAWS: A Framework for Executing Adaptive Web-Service Processes

paper_content:

The processes with adaptive Web services framework couples design-time and runtime mechanisms to flexibly and adoptively execute managed Web-services-based business processes.
---
paper_title: Cremona: an architecture and library for creation and monitoring of WS-agreents

paper_content:

Using services across domain boundaries, be they organizations or self-managing components of large distributed systs, requires the setup of an agreent between the parties involved, defining the terms of the service including interfaces, security and Quality of Service (QoS) properties. In an on-dand environment in which services are contracted on a short notice, the establishment of an agreent as well as the setup of agreement-fulfilling and monitoring systs of the parties involved must be spontaneous and, partially, automated. WS-Agreent is a standardization effort being conducted in the Global Grid Forum defining a simple agreent establishment protocol, an XML-representation of agreements and agreent tplates as well as a runtime agreement monitoring interface, based on the WSRF set of standards. WS-Agreent standardizes the interaction between the organizational domains. In addition, providers require an infrastructure to manage agreent tplates, implent the interfaces, check availability of service capacity and expose agreement states at runtime. Also, agreent requesters need infrastructure to read tplates, fill in tplates to create suitable agreements, and monitor agreent state at runtime. Crona (Creation and Monitoring of Agreents) proposes an architecture for the WS-Agreent-implenting middleware. In addition, the Crona Java Library implents the WS-Agreent interfaces, provides management functionality for agreement tplates and instances, and defines abstractions of service-providing systs that can be implented in a domain-specific environment.
---
paper_title: Enabling Robustness in Existing BPEL Processes

paper_content:

Web services are increasingly being used to expose applications over the Internet. To promote efficiency and the reuse of software, these web services are bei ng integrated both within enterprises and across enterprises, creating higher function services. BP EL is a workflow language that can be used to facilitate this integration. Unfortunately, the autonomo us nature of web services leaves BPEL processes susceptible to the failures of their constituent services. In this paper, we present a systematic approach to making existing BPEL processes more fault tolerant by monitoring the involved web services at runtime, and by replacing delinquent web services dynamically. To show the feasibility of our approach, we developed a prototype implementation that generates more robust BPEL processes from existing ones automatically. The use of the prototype is demonstrated using an existing loan approval BPEL process.
---
paper_title: TRAP/BPEL: A framework for dynamic adaptation of composite services

paper_content:

TRAP/BPEL is a framework that adds autonomic behavior into existing BPEL processes automatically and transparently. We define an autonomic BPEL process as a composite Web service that is capable of responding to changes in its execution environment (e.g., a failure in a partner Web service). Unlike other approaches, TRAP/BPEL does not require any manual modifications to the original code of the BPEL processes and there is no need to extend the BPEL language nor its BPEL engine. Furthermore, TRAP/BPEL promotes the reuse of code in BPEL processes as well as in their corresponding autonomic behavior. In this paper, we describe the details of the TRAP/BPEL framework and use a case study to demonstrate the feasibility and effectiveness of our approach.
---
paper_title: Worklets: A Service-Oriented Implementation of Dynamic Flexibility in Workflows

paper_content:

A yoke for a hookes universal joint, formed of a lightweight metal and having a base, two limbs extending axially from the base, the limbs having reinforcing flanges at least adjacent to the base and the thickness of the base being such that the limbs and base form a generally U-shaped structure of high rigidity.
---
paper_title: Using role-based coordination to achieve software adaptability

paper_content:

Software systems are becoming more open, distributed, pervasive, and connected. In such systems, the relationships between loosely-coupled application elements become non-deterministic. Coordination can be viewed as a way of making such loosely coupled systems more adaptable. In this paper we show how coordination-systems, which are analogous to nervous systems, can be defined independently from the functional systems they regulate. Such coordination-systems are a network of organisers and contracts. We elaborate how contracts can be used to monitor, regulate and configure the interactions between clusters of software entities called roles. Abstract management contracts regulate the flow of control through the roles and provide monitoring interception points. Concrete contracts are domain specific and allow the specification of performance conditions. These contracts bind clusters of roles into self-managed composites - each composite with its own organiser role. The organiser roles can control, create, abrogate and reassign contracts. Adaptive systems are built from a recursive structure of such self-managed composites. A prototype framework has been built from which adaptive applications can be derived. This framework uses association-aspects as a mechanism to implement contracts.
---
paper_title: Extending BPEL for run time adaptability

paper_content:

The existing Web service flow (WS-flow) technologies enable both static and dynamic binding of participating Web services (WSs) on the process model level. Adaptability on per-instance basis is not sufficiently supported and therefore must be addressed to improve process flexibility upon changes in the environment. Ad-hoc process instance changes can be enabled by swapping participating WS instances, by modifying port types of the partners to be invoked, and by changing process logic. In this work, we address the problem of dynamic binding of WSs to WS-flow instances at run time, i.e. the ability to exchange a WS instance participating in a WS-flow instance with an alternative one. The problem is additionally complicated by the fact that the execution of a process depends on its deployment. We describe the "find and bind" mechanism, and we show its representation as a BPEL extension. We discuss the benefits that could be gained and the disadvantages it brings in. The mechanism extends and improves the existing process technologies. It facilitates a precisely controlled policy-based selection of WSs at run time and also provides for process instance repair, while maintaining simplicity. We also discuss a prototypical implementation of the presented functionality.
---
paper_title: Robustbpel-2: Transparent autonomization in aggregate web services using dynamic proxies

paper_content:

We recently introduced RobustBPEL [13], a software toolkit that provides a systematic approach to making existing aggregate Web services more tolerant to the failure of their constituent Web services. Using RobustBPEL, we demonstrated how an aggregate Web service, defined as a BPEL process, can be instrumented automatically to monitor its partner Web services at runtime and replace failed services via a generated proxy. While in the previous work the proxy is statically bound to a limited number of alternative Web services, in this paper we propose an extension to the RobustBPEL toolkit to generate a proxy that dynamically discovers and binds to existing services. Further, we prese nt details of the generation process, the architecture of the dynamic proxy, and finally use a case study to demonstrate how the generated dynamic proxy is used to support self-healing and self-optimization (specifically, to improve the fault-tolerance and performace) in an instrumented BPEL process.
---
paper_title: Case handling: a new paradigm for business process support

paper_content:

Case handling is a new paradigm for supporting flexible and knowledge intensive business processes. It is strongly based on data as the typical product of these processes. Unlike workflow management, which uses predefined process control structures to determine what should be done during a workflow process, case handling focuses on what can be done to achieve a business goal. In case handling, the knowledge worker in charge of a particular case actively decides on how the goal of that case is reached, and the role of a case handling system is assisting rather than guiding her in doing so. In this paper, case handling is introduced as a new paradigm for supporting flexible business processes. It is motivated by comparing it to workflow management as the traditional way to support business processes. The main entities of case handling systems are identified and classified in a meta model. Finally, the basic functionality and usage of a case handling system is illustrated by an example.
---
paper_title: Constraint-based workflow models: Change made easy

paper_content:

The degree of flexibility of workflow management systems heavily influences the way business processes are executed. Constraint-based models are considered to be more flexible than traditional models because of their semantics: everything that does not violate constraints is allowed. Although constraint-based models are flexible, changes to process definitions might be needed to comply with evolving business domains and exceptional situations. Flexibility can be increased by run-time support for dynamic changes - transferring instances to a new model - and ad-hoc changes - changing the process definition for one instance. In this paper we propose a general framework for a constraint-based process modeling language and its implementation. Our approach supports both ad-hoc and dynamic change, and the transfer of instances can be done easier than in traditional approaches.
---
paper_title: Hybrid web service composition: business processes meet business rules

paper_content:

Over the last few years several process-based web service composition languages have erged, such as BPEL4WS and BPML. These languages define the composition on the basis of a process that specifies the control and data flow among the services to be composed. In this approach, the whole business logic underlying the composition including business policies and constraints is coded as a monolithic block. As a result, business rules are hard to change without affecting the core composition logic. In this paper, we propose a hybrid composition approach: The composition logic is broken down into a core part (the process) and several well-modularized business rules that exist and evolve independently. We also discuss two alternative technologies for implenting business rules in encapsulated units, using aspects and a rule-based engine. Our approach allows for a more modular and flexible web service composition.
---
paper_title: Enabling On-the-Fly Business Process Composition through an Event-Based Approach

paper_content:

Agility is a key characteristic for modern enterprises operating in a highly dynamic environment. The attainment of agility is a difficult issue involving all organizational aspects, such as business processes, information systems, personnel, organizational structure, etc. The ability to respond rapidly to changes by utilizing agile business processes is an important constituent of an agile enterprise. The focus of this paper is business process agility outlining the benefits of event-based business process modeling. To this end, an event-based approach is proposed enabling on-the-fly composition of business processes. The introduced approach adopts the concepts of complex event processing. A conceptual architecture for an information technology infrastructure supporting event-driven business process execution is also proposed.
---
paper_title: Dynamic Routing as paradigm for decentralized flexible process management

paper_content:

Since companies face continuously changing business processes, centralized process repositories and execution engines have been integrated into the heart of enterprise systems. These systems are then able to support repetitive processes. In order to extend the reach of process orientation into more collaborative settings, employees must be given the possibility to adapt and refine the processes to their individual needs. Personalized process templates are applied to tasks and running process instances are subject to massive changes by the participants. These flexible processes require for process management infrastructures of a more peer to peer style. We argue that the concept of Dynamic Routing is a valuable paradigm for supporting highly flexible processes. We identified three patterns for Dynamic Routing and sketch future enterprise system architectures implementing these. We present two case studies where dynamically routed interactions are at the center of attention.
---
paper_title: TRAP/BPEL: A framework for dynamic adaptation of composite services

paper_content:

TRAP/BPEL is a framework that adds autonomic behavior into existing BPEL processes automatically and transparently. We define an autonomic BPEL process as a composite Web service that is capable of responding to changes in its execution environment (e.g., a failure in a partner Web service). Unlike other approaches, TRAP/BPEL does not require any manual modifications to the original code of the BPEL processes and there is no need to extend the BPEL language nor its BPEL engine. Furthermore, TRAP/BPEL promotes the reuse of code in BPEL processes as well as in their corresponding autonomic behavior. In this paper, we describe the details of the TRAP/BPEL framework and use a case study to demonstrate the feasibility and effectiveness of our approach.
---
paper_title: Patterns of Business Rules to Enable Agile Business Processes

paper_content:

A problem of today's standard business process (BP) automation systems is that they are too rigid to cope with changing business demands, especially for long running BPs. A solution to overcome this problem is to combine BPs with business rules (BR). State of the art BP automation systems are based on Web service (WS) technology and use WS composition languages, for example BPEL, for abstract and executable BPs. On the other hand, most of today's implementations use BRs mostly to make calculations and to adapt simple decisions to business users without full integration into a BP automation system. We will show that BP execution and BR functionality can be integrated properly in a standard service oriented architecture. This finding will be applied in a new approach of configuring BPs through using BRs. The assumption is that if one considers BRs already while modeling a BP, more advanced BP aspects like decisions, data constraints and control flow can be made agile and adaptive during run-time. We present multiple solutions demonstrating how BRs can be used to obtain different aspects ofBP agility. Described as BP Modeling Patterns, our solutions give insight on how agile BPs can be implemented with current BP automation technology. We implemented them using IBM WebSphere integration developer and IBM WebSphere process server.
---
paper_title: Making BPEL Flexible – Adapting in the Context of Coordination Constraints Using WS-BPEL

paper_content:

Although WS-BPEL is emerging as the prominent language for modeling executable business processes, its support for designing flexible processes is limited. An important need of many adaptive processes is for concurrent activities in the process to respect coordination constraints. These require that concurrent activities coordinate their behaviors in response to exogenous events. We show how coordination inducing constraints may be represented in WS-BPEL, and use generalized adaptation and constraint enforcement models to transform the traditional BPEL process to an adaptive one. The final outcome is an executable WS-BPEL process without extensions, able to adapt to events while respecting coordination constraints between activities.
---
paper_title: Robustbpel-2: Transparent autonomization in aggregate web services using dynamic proxies

paper_content:

We recently introduced RobustBPEL [13], a software toolkit that provides a systematic approach to making existing aggregate Web services more tolerant to the failure of their constituent Web services. Using RobustBPEL, we demonstrated how an aggregate Web service, defined as a BPEL process, can be instrumented automatically to monitor its partner Web services at runtime and replace failed services via a generated proxy. While in the previous work the proxy is statically bound to a limited number of alternative Web services, in this paper we propose an extension to the RobustBPEL toolkit to generate a proxy that dynamically discovers and binds to existing services. Further, we prese nt details of the generation process, the architecture of the dynamic proxy, and finally use a case study to demonstrate how the generated dynamic proxy is used to support self-healing and self-optimization (specifically, to improve the fault-tolerance and performace) in an instrumented BPEL process.
---
paper_title: Case handling: a new paradigm for business process support

paper_content:

Case handling is a new paradigm for supporting flexible and knowledge intensive business processes. It is strongly based on data as the typical product of these processes. Unlike workflow management, which uses predefined process control structures to determine what should be done during a workflow process, case handling focuses on what can be done to achieve a business goal. In case handling, the knowledge worker in charge of a particular case actively decides on how the goal of that case is reached, and the role of a case handling system is assisting rather than guiding her in doing so. In this paper, case handling is introduced as a new paradigm for supporting flexible business processes. It is motivated by comparing it to workflow management as the traditional way to support business processes. The main entities of case handling systems are identified and classified in a meta model. Finally, the basic functionality and usage of a case handling system is illustrated by an example.
---
paper_title: Product Based Workflow Support: Dynamic Workflow Execution

paper_content:

Product Based Workflow Design (PBWD) is a successful new approach to workflow process support. A description of the product, the Product Data Model (PDM), is central to this approach. While other research so far has focused on deriving a process model from the PDM, this paper presents a way to directly execute the PDM. This leads to a more dynamic and flexible support for the workflow process.
---
paper_title: Dynamic reconfiguration using template based web service composition

paper_content:

Current workflow languages introduce limitations regarding modularity and flexibility. They are lacking support for reusability of primitive and structured activities. Designing processes often leads to duplication which makes the workflow descriptor complicated and unnecessarily large. Furthermore, due to the static character of the scripts, there is insufficient flexibility to model dynamic, evolvable and failsafe workflows. In this paper we present a framework that allows the design of WS-BPEL processes in a modular way based on reusable templates. In addition, we introduce an extra layer on top of WS-BPEL that allows template processing based on parameter values. This layer offers support for decision logic to adapt processes dynamically. The approach is based on the "Ruby On Rails" (RoR) framework, known for adding dynamism to static web pages. The proposed solution is portable with existing WS-BPEL engines.
---
paper_title: Constraint-based workflow models: Change made easy

paper_content:

The degree of flexibility of workflow management systems heavily influences the way business processes are executed. Constraint-based models are considered to be more flexible than traditional models because of their semantics: everything that does not violate constraints is allowed. Although constraint-based models are flexible, changes to process definitions might be needed to comply with evolving business domains and exceptional situations. Flexibility can be increased by run-time support for dynamic changes - transferring instances to a new model - and ad-hoc changes - changing the process definition for one instance. In this paper we propose a general framework for a constraint-based process modeling language and its implementation. Our approach supports both ad-hoc and dynamic change, and the transfer of instances can be done easier than in traditional approaches.
---
paper_title: Hybrid web service composition: business processes meet business rules

paper_content:

Over the last few years several process-based web service composition languages have erged, such as BPEL4WS and BPML. These languages define the composition on the basis of a process that specifies the control and data flow among the services to be composed. In this approach, the whole business logic underlying the composition including business policies and constraints is coded as a monolithic block. As a result, business rules are hard to change without affecting the core composition logic. In this paper, we propose a hybrid composition approach: The composition logic is broken down into a core part (the process) and several well-modularized business rules that exist and evolve independently. We also discuss two alternative technologies for implenting business rules in encapsulated units, using aspects and a rule-based engine. Our approach allows for a more modular and flexible web service composition.
---
paper_title: A declarative approach for flexible business processes management

paper_content:

Management of dynamic processes in an important issue in rapidly changing organizations. Workflow management systems are systems that use detailed process models to drive the business processes. Current business process modelling languages and models are of imperative nature – they strictly prescribe how to work. Systems that allow users to maneuver within the process model or even change the model while working are considered to be the most suitable for dynamic processes management. However, in many companies it is not realistic to expect that end-users are able to change their processes. Moreover, the imperative nature of these languages forces designer to over-specify processes, which results in frequent changes. We propose a fundamental paradigm shift for flexible process management and propose a more declarative approach. Declarative models specify what should be done without specifying how it should be done. We propose the ConDec language for modelling and enacting dynamic business processes. ConDec is based on temporal logic rather than some imperative process modelling language.
---
paper_title: Constraint-based workflow models: Change made easy

paper_content:

The degree of flexibility of workflow management systems heavily influences the way business processes are executed. Constraint-based models are considered to be more flexible than traditional models because of their semantics: everything that does not violate constraints is allowed. Although constraint-based models are flexible, changes to process definitions might be needed to comply with evolving business domains and exceptional situations. Flexibility can be increased by run-time support for dynamic changes - transferring instances to a new model - and ad-hoc changes - changing the process definition for one instance. In this paper we propose a general framework for a constraint-based process modeling language and its implementation. Our approach supports both ad-hoc and dynamic change, and the transfer of instances can be done easier than in traditional approaches.
---

Title: Support for Business Process Flexibility in Service Compositions: An Evaluative Survey
Section 1: INTRODUCTION
Description 1: Write about the motivation for the survey, the importance of business process flexibility, and an overview of existing issues and approaches.

Section 2: SCENARIO
Description 2: Describe a business scenario that illustrates the need for process flexibility in service compositions.

Section 3: REQUIREMENTS FOR PROCESS FLEXIBILITY
Description 3: Identify and analyze the detailed requirements for modeling and enacting business processes flexibly in service compositions.

Section 4: Process definition flexibility
Description 4: Discuss the requirements at the process definition level, highlighting various approaches to achieve configurability, ease of understanding, late specification, automated change verification, and merging business process definitions.

Section 5: Process instance flexibility
Description 5: Elaborate on the requirements for process instance flexibility, including process instance deviation, handling as a case, migration, and ease of human understanding and intervention.

Section 6: Services relationship flexibility
Description 6: Address the requirements for flexibility in service relationships, focusing on changing service interfaces, service bindings, and inter-service relationships.

Section 7: EVALUATION OF EXISTING APPROACHES
Description 7: Analyze and evaluate how various existing approaches address the identified requirements for process flexibility.

Section 8: DISCUSSION
Description 8: Present observations on the analyzed approaches, categorize them, and discuss the interplay between different levels of process flexibility.

Section 9: RESEARCH CHALLENGES
Description 9: Identify and discuss research challenges in achieving highly flexible business process modeling and enactment for service-oriented systems.

Section 10: CONCLUSION
Description 10: Summarize the systematic analysis, highlight the importance of flexible service relationships, and suggest areas for future investigation.