Why is software quality assurance important?

Lean Manufacturing is a methodology that focuses on loss reduction, and Lean Manufacturing usually implements standard solutions to solve various process problems: as a rule, losses, defects, uneven flow, and cycle time. Whereas Six Sigma addresses problems with an unknown solution. Decisions in Six Sigma may not be standard at all, depending on the information obtained through a thorough examination of the data. Companies currently use the integrated Six Sigma methodology.

Let’s start with Lean Development.

Lean Development

Principles. Benefits. Facts.


  1. Eliminate waste

Wastes are considered to be everything that adds any values for users: excessive functionality, waiting for other activities, teams, processes, switching people between tasks, the motion required to complete work, managerial overhead not producing real value, defects and lower quality.

2. Amplify learning

Short iteration cycles, early testing, increasing feedback via short feedback sessions help both customer representatives and the development team learn more about the domain problem and figure out possible solutions for further development.

3. Decide as late as possible

Better results should be achieved with a set-based or options-based approach, delaying decisions as much as possible until the1y can be made based on facts and not on uncertain assumptions and predictions.

4. Deliver as fast as possible

The shorter the iterations, the better the learning and communication within the team.

5. Empower the team

People should not be seen exclusively as a resource. People need something bigger than just a list of tasks.

“Find good people and let them do their own job.”

6. Build integrity in

It is about referring the comprehensive information to the client and aiming for an accurate architecture. One of the healthy ways towards integral architecture is refactoring. As more features are added to the original code base, the harder it becomes to add further improvements. Refactoring is about keeping simplicity, clarity, minimum number of features in the code.

7. See the whole

“Think big, act small, fail fast; learn rapidly.”


Lean Development

  • rationalizes and simplifies the development process
  • means Short-term development = fast release of the product
  • helps not just perform the tasks, but aims for the product with the least number of defects
  • reduces the costs of the projects
  • helps Become closer to your customer
  • increases the team involvement rate

Why Six Sigma?

The Six Sigma method is an approach to improving the production process by searching for and eliminating the causes of errors or defects in business processes, focusing on the output parameters critical for the consumer.

The Six Sigma theory is based on six points on which the effectiveness of business processes depends.

1) Expression of interest in the client. This is reflected in continuous monitoring and analysis of customer needs.

2) Management based on verified data and facts, and not on the basis of assumptions that may happen with a certain probability.

3) Orientation to the production process. Constant process management, improvement, process improvement. The entire production cycle can be divided into separate processes and manage them — this is based on the basis of the process approach to management.

4) Proactive management (ahead of schedule). Leaders do not expect what can happen but warn of possible changes.

5) Openness to cooperation, transparency of production for both customers and suppliers.

6) Continuous improvement. Any process of quality improvement is associated with continuous improvement, and a condescending attitude towards failures is to overcome and learn from them.

To implement the Six Sigma method, Motorola proposed a systematic course of action called DMAIC (English define, measure, analyze, improve, control), which consists of five steps:

1. Define

  • definition of project goals and consumer requests (internal and external);

2. Measure

  • process measurement to determine the current execution;

3. Analyze

  • defect analysis
  • determination of the causes of defects;

4. Improve

  • process improvement through reduction of defects;

5. Control

  • control of the further course of the process.

How do these methods complement each other?

The concept of Lean Production, having changed the culture of production, over time expanded the toolkit, included the ideas of the stream of creating value, a method of protection against errors, and was transformed into Lean Management. By the end of the 20th century, both of these concepts (Lean and Six Sigma) were the most sought-after areas of business consulting in quality management, since the number of successful implementations in relation to the total number of implementations turned out to be higher than other quality management methods. Together, they showed even greater effectiveness.

How does Six Sigma method complement the Lean method?

Lean does not establish the infrastructure requirements necessary to implement the concept. The solution to this issue depends on the initiative of managers and their organizational abilities, and when changing the composition of managers, difficulties arise with the transition. Six Sigma helps formalize the commitments of senior management, create a plan for the allocation of resources and control the success of their development. The Lean concept is not as strict as in Six Sigma, a focus on consumer needs is defined. Satisfying requests from eliminating production costs and non-production losses depends indirectly, while in Six Sigma, the definition of consumer requirements begins with a description of the principles of the DMAIC concept: Define, Measure, Analyze, Improve, Control (Russian: Define. Measure. Analyze. Improve. Manage). Defects, in the framework of the Lean concept, are named as the main sources of production losses, but the statistical control methods for eliminating them are spelled out in Six Sigma.

How does Lean supplement with Six Sigma?

Six Sigma describes methods for eliminating defects, but, in addition to defects, Lean Management also lists the factors of expectation, transportation, overproduction, stocks, movement of people and activities that do not add value. Sometimes practitioners also emphasize the use of low-quality raw materials (“false savings”) and diversity, as a result of unified components of the process. Six Sigma does not explain the relationship between customer satisfaction (quality) and process duration. Thanks to the Lean system, the concept of “time” is introduced as a key. Lean expands the range of tasks that Six Sigma describes, adding the elimination of unproductive activities, optimizing the workplace, reducing inventory, reducing transportation costs, etc. Moreover, both basic systems are characterized by a focus on a single process (in contrast to the previous concepts trying to achieve universal coverage). This originality has been preserved by the synthesized concept.

To sum up:

Lean Methodology

Goal — reduce the losses and acceleration of processes

Focus — the time for the process, work-in-progress, valuable and invaluable operations

Methods — Kaizen projects, value stream mapping, continuous improvement

Process acceleration method (Lean) provides improvement of quality Six Sigma

Six Sigma Methodology

Goal — increase customer satisfaction, reduce the number of defects

Focus — the source of the problem, variability

Methods- DMAIC (define, measure, analyze, improve, control) projects, the involvement of employees and the executives of the company into the optimization processes, statistical methods, Total Quality Management (TQM)

Quality Improvement Method Six Sigma provides acceleration of Lean processes.

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