5 Why Analysis – A Root Cause Analysis Tool

5 Why Analysis is a simple approach for exploring root causes and instilling a “Fix the root cause, not the symptom,” culture at all levels of a company. The 5 Why Analysis was originally developed by Toyota founder Sakichi Toyoda and was later used within Toyota Motor Corp. during the development of the Toyota Product System (TPS). At Toyota, 5 Whys is still a critical component of problem-solving training, and the method is still widely applied within the company when problems occur.

“Toyota Business Practices dictates using the ‘Five Whys’ to get to the root cause of a problem, not the ‘Five Whos’ to find a fire the guilty party.” – Jeff Liker, The Toyota Way

It can be used whenever the real cause of a problem or situation is not clear. Using the 5 Whys is a simple way to try solving a stated problem without a large detailed investigation requiring many resources. When problems involve human factors this method is the least stressful on participants. It is one of the simplest investigation tools easily completed without statistical analysis. Also known as a Why Tree, it is supposedly a simple form of root cause analysis. Application of the procedure involves taking any problem and asking “Why – what caused this problem?” Then, when the cause is identified, asking “Why?” again (i.e. “what caused the cause?”) The strategy, as commonly understood, is to ask “Why” five times or more uncovering links in a causal chain going back in time. By repeatedly asking the question, ‘Why?’ you peel away layers of issues and symptoms that can lead to the root cause.… Read the rest

Goldratt’s Theory of Constraints – Constraint Management

An Israeli physicist, Eliyahu Goldratt wrote a book titled ‘The Goal’, about a factory manager’s quest to save his factory from being closed down for lack of profitability. It chronicles the process that the manager and his staff go through as they learn how to save their factory. What they learn is how to apply the principles of what Mr. Goldratt calls the “Theory of Constraints.”

Theory of Constraints (TOC) is a logic-driven approach which focuses on system improvement. The core idea of TOC is that every organization has at least one constraint that prevents management from achieving the goal of the organization to a larger degree.

A system can be defined as a collection of interrelated, interdependent components or processes that act in concert to turn inputs into defined outputs in pursuit of a particular goal. Linking systems to chains, TOC defines weakest link as a Constraint. Constraint limits the systems performance. A constraint determines the maximum capacity of a System. Theory of Constraints assumes that every system has at least one constraint that prevents from achieving the system goals. The performance of the entire system is limited by the constraint. Constraints can be physical resources or policies. TOC develops a set of procedures and methodologies to identify and optimize such constraints. Theory of Constraints helps to increase throughput, reliability, and quality while decreasing inventory, late deliveries, and overtime.

Goldratt introduced a method called the five focusing steps for addressing system problems on a continuous improvement basis. The steps are:

  1. Identify the constraint: Identify the operation that is limiting the productivity of the system.
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Six Sigma – A Business Process Improvement Methodology


“It’s the only program I’ve ever seen where customers win, employees are engaged and satisfied, and shareholders are rewarded.” – Jack Welch

Historical Background of Six Sigma

Around 1980 Robert Galvin, at that time CEO at Motorola, realized the importance of working systematically with variance reduction as the Japanese had done for a prolonged period. Together with Bill Smith, Mikel Harry and Richard Schroeder, he created an improvement program that was given the name Six Sigma. Bill Smith came up with the idea of “inserting hard-nosed statistics into the blurred philosophy of quality”. The program was inspired by Japanese work, but also strongly influenced by Juran’s thoughts. Due to Six Sigma, Motorola managed to reduce their costs and variation in many processes and were an inaugural winner of America’s Malcolm Baldrige National Quality Award in 1988. They reported a profit from the program of USD 700 million for 1991 alone.

“We quickly learned if we could control variation, we could get all the parts and processes to work and get to an end result of 3.4 defects per 1 million opportunities, or a Six Sigma level. Our people coined the term and it stuck. It was shorthand for people to understand that if you can control the variation, you can achieve remarkable results.” – Robert W.

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Lean Thinking

Concept of Lean Thinking

Lean Thinking originated from manufacturing methods used by Japanese automotive manufacturers, especially from Toyota. Lean thinking is basically about getting the right things, to the right place, at the right time, in the right quantity while minimizing waste and waiting time and being flexible and open to change.

A term coined by James P. Womack and Daniel T. Jones in their book “Lean Thinking: Banish Waste and Create Wealth in Your Corporation” to describe an exceptionally focused, efficient, agile and successful organisation. Lean thinking provides a way to specify value, sequence value-creating actions in the best way, conduct these activities without interruption whenever someone requests them, and perform them more and more effectively.  Lean thinking means doing more and more with less and less resources while providing customers with exactly what they want.

“Becoming ‘lean’ is a process of eliminating waste with the goal of creating value.”

The lean way is about banishing waste or muda which is the Japanese word for waste.  Muda is the centre of the lean thinking. Waste is any human activity that allocates resources but generates no value. For example, production of products that are not in demand, processing activities that are not needed and unnecessary transportation of goods. In order to become a lean organization, it is fundamentally important to eliminate and to avoid all following types of waste.

  • Mistakes which require rectification,
  • Production of items no one wants,
  • Processing steps which aren’t actually needed,
  • Movement of employees and transport of goods from one place to another without any purpose,
  • Groups of people remaining idle  because an upstream activity has not delivered on time,
  • Goods and services which don’t meet the needs of the customer.
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Line Balancing in Production Management

A production line is typically associated with continuous or flow production system. Production lines are particularly appropriate for high volume operations. In a production line work is divided into individual tasks and assigned to consecutive workstations on the line. In mass production on progressive assembly line the workload between various machines or workstations should be balanced. The need for balancing the line becomes obvious when it is considered that the output to be received from the line is determined by the maximum time involved in the performance of work at one particular workstation. The imbalances existing in the line would lead to wastage of time at all other work stations when one work station holds up the total output rate. Therefore, it is necessary to level out or balance the cycle times at each workstation.

Line balancing refers to the apportionment of sequential work activities into workstations in order to achieve maximum possible utilization of facilities and to minimize idle time. In case of wholly automated operations, line balancing is largely achieved through engineering design. In other cases balancing of equipment capacities poses a problem. If the time requirements at one workstation are very large in comparison with other stations, the tasks at the station may have to be further subdivided or additional personnel may be added to the station. Alternatively, a parallel section may be provided so that two or more units may be worked on simultaneously. The speed of an assembly line is determined by the desired rate of output, spacing of products on the line, time requirements of workstations, and pace considerations appropriate to the workers.… Read the rest

Quality Control (QC)

What is Quality?

Quality has become one of the most important factors of consumers decision in selecting a product among competing products (services). This phenomenon is wide spread regardless of the fact whether the consumer is an individual organisation, retail store, or a military defense programme.

The quality of products / services can be evaluated in several ways. It is important to identify different dimensions of quality Garrin (1987) discusses eight components or dimensions of quality as follows.

  1. Performance (Will the product do intended job?)
  2. Reliability (How often does the product fail?)
  3. Durability (How long does the product last?)
  4. Serviceability (How easy is it to repair the products?)
  5. Aesthetics (How the product looks like?)
  6. Features (What does the product do?)
  7. Perceived Quality (What is the reputation of the company?)
  8. Conformance to standards (Is the product made exactly as the design indented?)
Meaning of Quality Control

Quality control means several things:

  1. To lay down the desirable norm or standard of quality expected of the article or product or service. This factor again is composed of two attributes.
    • The nature of the product.
    • The consumer or user satisfaction that is expected of it. Thus for a sophisticated machine tool are an automobile part or aircraft component or a ball bearing the highest precision, quality and rigid tolerance are necessary. For an ordinary kerosene stove the different components need not observe such rigid quality standard.
  2. To lay down the desirable quality. Each article carries with it a quality assurance. Quality control seeks to establish production condition by which variations form the expected quality standard are minimized.
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