Before comparing Quality Management (QM) approaches, it will help you understand better if we go back a little and take a quick look at these approaches.
As most of you know already, organizations exist to produce products and services. It can be compared with a three legged stool. First Leg is Input. Second Leg is transformation process and the third Leg is Output. Without these legs an organization would not be able to function. This is applicable for most of the organizations around the world. Let’s take a simple example. Let’s look at an organization from the Software Industry. A hypothetical company wants to produce software to support Green initiatives. In this case the input is skilled software Professionals, office, environment and the required tools. The process is Programming and the Output is software which supports Green initiatives. Similar to this example, at a higher level, any organization can be compared with a three legged stool.
The main objectives of these QM approaches are to make the three legged stool stronger than before by producing best quality products and services to differentiate it from other three legged stools. In general, Quality management approaches can be classified into two broad categories, industry-specific QM and non-industry-specific QM. For example, some QM program such as ISO 14000,AS9100, QS 9000, and TL 9000 are industry specific and others, including Lean management, Six Sigma, Total Quality Management, and ISO 9000:2000, are company-wide quality management programs. Our main objective is to compare the company-Wide QM approaches.
The Lean QM program mainly focuses on removing non-value-added activities from processes and services in an organization. Japanese engineers Taiichi Ohno and Shigeo Shingo, developed an approach called the Toyota production system, which the Western world calls Lean management. The main components of the Lean quality management system are called the 5S system: sort, set in order, shine, standardize, and sustain.
Similar to the principles of Lean management, Six Sigma has drawn intense interest from the business community. It was developed by Motorola in the 1980s and was popularized by General Electric’s chief executive officer (CEO) Jack Welch and others in the 1990s. Six Sigma is a data-driven approach for process improvement. Using statistical quality control and mathematical modeling in Six Sigma, one can reduce the defect rate between 3.4 per million and 2 per billion. The framework, called DMAIC (define, define the scope of the problem; measure, collect the data to analyze the problem; analyze, determine the root cause; implement, implement the solution to the problem, and control, monitor and make it defect free), is the heart of Six Sigma.
Similar to Lean management and Six Sigma is another quality management system called TQM. It is the subject of many books and research papers. It is not a new concept and is the extension of a company-wide quality concept from Japan. Researchers have identified several definitions for TQM. The commonly used definition of TQM is that it is an ongoing process whereby top management takes whatever steps necessary to enable everyone in the organization in the course of performing all duties to establish and achieve standards which meet or exceed the needs and expectations of their customers, both external and internal. Total quality management is a never-ending process to satisfy both the internal and the external customers and the core ideas presented by Deming, Juran, Crosby, and Ishikawa are the key elements of TQM.
ISO 9000 is another powerful QM system similar to Lean management, Six Sigma, and TQM which is being used in industries worldwide to support continuous improvement. The ISO 9000 standards are a set of international standards and guidelines developed by a technical committee composed of experts from business and other organizations around the world to promote QM in organizations. There are five ISO standards: ISO 9000, ISO 9001, ISO 9002, ISO 9003, and ISO 9004. The ISO 9000:2000 is the most comprehensive and it provides a model for quality assurance in design, development, production, installation, and services. The key principles of ISO 9000:2000 are customer focus, leadership, involvement of people, a process approach, a system approach to management, continual improvement, a factual approach to decision making, and mutually beneficial supplier relationships.
Now, let’s compare these approaches. Lean Management mainly focuses on Process flow. But Six Sigma is all about process performance and TQM focuses on all activities. ISO mainly focuses on documentation (a kind of inward looking approach). From an assumption standpoint, Lean assumes eliminating waste can improve performance. Six Sigma assumes that variation exists in all processes and analyzing the variation could improve performance. TQM assumes Deming’s chain of reaction. Edwards Deming’s chain of reaction approach improves quality, productivity, market share and decreases costs. It also helps the organization to stay in business and provide more jobs. I do not find any specific assumptions for ISO, but many believe that that ISO can safeguard customers.
Commonly noted benefits of Lean are Improving productivity, quality and flexibility. Likewise, the commonly noted benefits of Six Sigma are customer satisfaction and improving operational efficiency. TQM benefits are improving customer satisfaction and producing better product quality. Commonly observed benefits of ISO are better documentation, Quality awareness and help to take more market advantage. Finally from a critic’s standpoint, statistical analysis is not valued in Lean. Six sigma approaches and the DMAIC principle work well only if the variations are normal. TQM focuses on long term results instead of short term results. Of late, organizations give high priority to the projects which yield results within a short span of time. Financial improvements of implementing ISO were not proved well and it is the biggest criticism of using ISO to improve the quality of products and services.