Physical and functional objects (Continued)

    There are three ways to describe a process:

    How do they differ?

    Description of Existence

    I continue a series of articles on modeling issues by a business analyst in subject areas. In past articles, I showed how we produce a description of things. Let's repeat this one more time.

    The nature of spacetime

    To begin with, the world we perceive is a four-dimensional space-time. But not the space-time that mathematicians use in their reasoning. Rather, this is the space that physicists use. The difference is that in the physical world there are no points. There are objects that from the point of view of the observer can be considered point. But upon closer inspection, these points can be considered as infinite spaces. We often do not distinguish between the world we perceive and the mathematical abstraction created to describe this perception. In the abstraction created to describe the perceived world, there is the concept of a point. There are no dots in the real world. This is a huge difference between the simulated world and its model. The non-distinction between these two entities is the reason for the part of holivars that arose on the basis of the previous article. For example, we are not able to perceive a slice of the space-time continuum across the time axis, as ISO 15926 suggests, to define the concept of an event. Therefore, I will continue the discussion further, without being distracted by such concepts as points, slices of the space-time continuum, and other abstract objects. We will only work with objects of 4-D space-time that we really perceive.

    Defining Extent Boundaries

    In 4-D space-time, we select any arbitrary volume (extent). This extent can be connected, (for example, a stone), or be disconnected, (for example, a school, if it was built, then destroyed and re-built in a new place). To display extents, a diagram is often used in which three spatial coordinates are merged into one — the vertical axis, and the time coordinate is presented as the abscissa axis. In this view, the related object looks like this:

    And the unbound one looks like this:

    The first step in researching extent

    The connectedness of the volume or the absence of this connectedness does not matter for determining the extent. Further, we call the extent what we want to represent it:

    Object - means we will call it an object,

    Event - means we will call it an event,

    Operation, - we will call it an operation.

    Calling the extent of the event, we describe it as an event, bearing in mind that the width of the extent in time is zero from the point of view of the narrator. Let's call it an object, which means we will have to describe the geometric dimensions of the extent, and the temporary ones will no longer matter, but can be described additionally. We will call the operation — it is necessary to indicate the time boundaries, because the operation is described by the beginning and end of the operation in time, and spatial ones no longer matter, but can be described additionally.
    Next, we share our understanding of extent with other subjects. We begin the description of the extent only with facts, since facts are a description of the extent in terms of its physical properties. If we start the description right away from the subjective point of view, then it will be a subjective description, devoid of factual basis.
    Facts and their interpretation
    We often come up with a description of subjective assessment instead of a description of facts. For example, at an interview, a candidate tells us information: my boss was a real hard worker! This candidate forgets to describe the facts, immediately proceeding to describe the subjective perception of these facts. It is clear that not everyone will agree with such an assessment, and therefore it is better to always adhere to facts and only facts, the interpretation of which should be left to the listener. After the facts are described and studied, we can proceed to the interpretation of these facts.

    The second step in the study of extent

    The subjective interpretation of extent is a description of it from some point of view. For example, the extent from some point of view can be a hammer, and on the other - a nail clipper. A hammer and a claw hammer are subjective descriptions of the same extent - pieces of iron. It is clear that there are many points of view on the extent. Therefore, one physical object can have many interpretations.

    Interpretations can be combined, subtracted, and found intersections. For example, if an event has two interpretations: one is victory and the other is defeat, then there is a union of these interpretations: victory and defeat.

    The combination of interpretations is used to describe the functions of the enterprise. But I’ll talk about this after we classify the descriptions of extents (not in this article).

    Synthesis and analysis

    In the process of researching the subject area, it may turn out that, from the point of view of modeling goals, the extent boundaries are chosen incorrectly. Then the subject identifies other boundaries of the investigated extent and repeats the process of its description, and then gives a subjective assessment of this extent. It may happen that it is convenient for one subject to describe the extent as an event, and the other as an operation. Then there is a conflict, what is the extent? Event or operation? In fact, it should be possible to consider the extent from one and the other points of view. Such an opportunity should be wired into the methodology for the description of the subject area. For example, in ARIS it is possible to depict the extent as an event on one diagram, and depict it as an operation on another. For instance, event the delivery of finished goods to the warehouse with a certain degree of detail can turn into the operation of the delivery of finished goods to the warehouse. Therefore, what we consider the extent, what methods we use to describe this space, is for us to decide depending on the goals of modeling. And since each extent, in addition to what can be considered as an object, event, or operation, has many subjective interpretations, the modeling of these points of view should also be supported by the methodology of modeling the subject area. Now this possibility is absent in notations, which forces analysts to use some religious considerations in order to choose one from the many possible interpretations. This completes the modeling of the subject area and this completes the description of our picture of the world.


    In this article, I will continue to study the term event. But now I will consider not just a physical event, as it was in the previous article , but I will consider a functional event.

    Functional Events

    This event, which differs from the physical presence of a point of view on it.
    Recall how in the last article the work of a lighthouse is described by a caretaker. He divides the lighthouse into classes of states: "The fire is extinguished" and "The fire is burning up." He describes the events between these states as “Extinguishing stopped” and “Ignition stopped”.
    The description of the states looks like this:

    This activity can be depicted in the form of a diagram of processes, linking the states by events separating them.

    It can be seen from this diagram that the state and the operation are objects of one nature, because both are described by two events: the beginning of the state (operation) and the end of the state (operation).
    Process Cycle
    Here I ran a little ahead and showed you diagrams of processes that can be called cyclic (the state of the system cyclically passes through the states of the same classes (“off”, “on”). But if you look closely at the real processes, you will see those for example, the operation “Accepting an application” is preceded by the operation “Waiting for a client with an application.” It starts with the event “Customer applied” and ends with the operation “Waiting for receiving an application”, which, in turn, ends with the event “Customer applied”. Samsar Her mother)).

    The reason few people pay attention to this is because automated systems do not simulate client expectation, but perform this operation.

    Night, street, lantern, pharmacy,
    Pointless and dim light.
    Live another quarter century - Everything will be so. There is no outcome.

    If you die, you will start over again
    And everything will be repeated as if you were old:
    Night, icy ripples of the canal,
    Pharmacy, street, lantern.

    Question: Intermediate events in the diagram we give are physical or functional events? Another diagram will help us answer this question, on which the same events have a completely different name:

    Thus, we see that the diagrams depict functional events. If we recall that the interpretations of events can be combined, then we can redraw the diagram so as to take into account both points of view:

    Physical event

    But what is a physical event in our case? This is an event when the lighthouse keeper is sitting on a log and meditating. At this brief moment, he is gathering strength to continue his work. In this case, the fire is either burning or extinguished. All of these facts together constitute a physical event.


    Now consider the operation. For them, the same laws apply as for events: the division into physical and functional. And we must remember that the diagrams write the names of functional operations, but not physical ones.

    Functional operations

    Let us have 3 analysts who are in front of the coffee machine. Their task is to describe the interaction of this particular subject with this automaton. The subject approaches, analysts take pens and begin to record.

    The first analyst drew the following interaction scheme: The

    second - this:

    And the third one:

    All diagrams are correct, but different names in them indicate different functional operations that belong to the same extent. For example, the operation “Pay money” and the operation “Accept money” are two functional operations that describe one physical operation from different points of view. The first point of view is the point of view of the subject. The second point of view is the point of view of coffee machine manufacturers. The third point of view is the point of view of the baton, which (point of view) concentrates on the question of which actor the actor is waiting for. Depending on the goals of the simulation, we use one or another point of view. If we model the behavior of the subject, then the first. If we simulate the operation of the machine, then the second. If we depict objectivity, then the third. I said that you can combine points of view. Practice it yourself.

    Physical operation

    A physical operation is an extent that includes a subject who throws coins into a coin acceptor, a working coin recognition machine, and a counter that is incremented.

    One extent - different objects?

    I repeat that the same extent can be considered both an event, an operation, and an object. Therefore, we can assume that the temporary part of the door handle is an object, if we go to describe its geometric dimensions, an event, if we describe the event “The door opened”, and an operation if we describe the operation of opening the door.

    Intersection of Extents

    It is believed that the state or operation is described by the initial and final events. I agree with this, but with one caveat. If an event is understood to mean a moment in time (as is customary in ISO), then a contradiction arises when trying to determine the exact moment when it occurred. For example, when exactly did the Battle of Kulikovo event take place? There is no such moment. If we assume that the event is a 4-D extent, then we get another contradiction. It turns out that the extent of the operation has common parts with the extent of the event. And this means that a description in the form of an operation that has a beginning and an end is only an approximate description of reality. Here I agree. All our descriptions are just some approximate models that describe real objects rather simplistically. This simplification allows us to reduce the description to an acceptable level of detail, required in terms of modeling goals. As a result, reality and its model are related approximately as follows:

    Sometimes the extent of what we call an event is equal to the extent of the operation that this event describes. Think of examples yourself.

    Ways to describe events

    So, we realized that one of the ways to use events is to divide space-time into temporary parts. Each part is a state or operation, and an event is a conditional boundary between them. There are several ways to describe an event.

    The first way to describe events

    A complete classification of the extent descriptions has not yet been given, and therefore at this stage you can just play around. For example, events can be described using boundary states. There is one state of the system, there is a second, and both of them are described. An event is declared as a transition from one state to another, which is represented by an arrow in the state diagram. For example, there is a tomato green state and a tomato red state. The transition between these states is an event. We are well aware that the transition has a nonzero time interval. However, from the point of view of the narrator, the width of this interval is not significant. The description of the event includes a description of two states: tomato green and tomato red, as well as the time interval during which the change of state occurred. For example, on the night of August 5th, on the 6th, the tomato ripened.
    Partridge Error
    This is exactly what Chris Partridge should have done in the book Business Objects: Re-Engineering for Re-Use when describing the Tomato Ripe event. He came up with a kind of “Complex event” that distinguishes from simple one in that it supposedly consists of simple ones, but the author could not describe it clearly. Here is an example from his book in which he gives a space-time diagram.

    The second way to describe events

    Another way to describe an event is to describe it as a state. For example, the event “Ignition started” can be described as follows: “The caretaker is resting.”

    What I don't like in ISO 15926

    In ISO 159126, an event refers to a point in time. And the interpretation of the moment in time is as follows: this is a 4-D slice of space-time perpendicular to the time axis. That is, is the whole universe at time t. How does this differ from the definition given by us? First, why do we need the whole universe? We work in a limited area of ​​space. And simultaneity on this site is determined by us visually (on one clearing), chronometers (on the globe) and some kind of theory of relativity within the limits of near space. But, as soon as we begin to understand what simultaneity is in general, we get the collision and impossibility of this definition. Secondly, a section of the universe is a geometric abstraction, which we tried to get rid of with all our might. After all, the definition that I gave is understandable from the point of view of common sense. And what gives ISO, comes not from common sense, but from mathematical abstraction (exactly what Kolmogorov said in his geometry textbook for the 6th grade!) If we accept the definition of ISO 15926, the question arises: which of the moments is considered an event? For example, an analyst may ask: “What is the event 'customer came?' The answer may be: “This is the moment when his crown crossed the plane of the doorway of the office” Do you like this definition of event? I don’t, because I will immediately ask, “what is the crown?” and "what is a doorway?" etc. Therefore, the ISS is a definitive definition of an event that is turned upside down. It includes what we do not need - the whole universe, and even an abstraction with which to work is unthinkable! Mine is quite justified, because it is always locally (limited by the scope of the simulated space), and understandable.

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