2.3. Are Six Sigma, Lean Six Sigma, Design for Six Sigma, TQM and QbD just using the same tools o rare they pursuing similar objectives?

Trying to define whether and how these approaches actually differ from each other is anything but straightforward as all of them are indeed very much interconnected and for sure all are using the same set of tools to achieve their objectives, i.e. Voice of the Customer, Kano Model, Pugh Matrix for Quality Function Deployment, TRIZ, 37 House of Quality, FMEA, Function simulation, Monte Carlo Simulation, Finite elements methodology, Capability prediction, DOE, Score Cards,....

The Six Sigma initiatives also pursue quite similar objectives in their attempt to improve quality by reducing variation and increasing robustness in production (Six Sigma), or to improve innovation to develop better products faster in R&D (Design for Six Sigma) and by applying Lean Six Sigma focusing only on the essentials, eliminating steps which are considered unimportant. Also the methodology used for all approaches is quite similar requiring a systematic, stepwise procedure: Define - Measure – Analyse – Improve – Control and this may require several cyclic repetitions. Also depending whether the focus is improvement, problem solving, or a new development slight alterations and additional steps may be needed. As such a Design for Six Sigma approach for a new product according to IDDOV involves.³⁸

• Identification of the needs of the customer (VOC) and how these can be targeted with the product (Identify)
• Specification of the specific product requirements to ensure the product targets are met (Define)
• Definition and evaluation of possible solutions and how these will meet the product specification and at which quality level and efficiency the designed processes will achieve to do so (Design)
• Testing the designed options and optimising these until all requirements are met consistently at the desired quality and efficiency (Optimise)
• Assuring the robustness of the designed product and process by establishing suitable controls to ensure future compliance with the defined quality criteria or efficiency ratios (Verify)

Total Quality Management was introduced by Toyota in the 1960s and has since then been adapted by many other companies and industries. It describes the alignment of all functions and all value chain activities within an organisation to build or improve a distinctive competency in the way a company develops, sources, manufactures, distributes, markets and services its products always focusing on superior quality as to both, excellence and reliability. This presents a holistic approach involving all organisational functions, from R&D to logistics, from information management systems to production, and from supply chain functions to marketing & sales (customer service), management, controlling, human resources, and others. It also needs to be integrated into the organisational structure at the company’s normative, strategic and operational level, supported by the corporate vision and culture, the strategic decisions and operational management activities. Therefore, TQM must include management commitment and accountability, participation and training of employees, continuous learning, innovation and improvement systems, partnership management (includes suppliers, distributors, after sales service, CROs,...), customer focus and a focus on optimisation.

The tools such as flexible manufacturing units, Six Sigma approaches, or JIT inventories to achieve TQM need to be integrated into the structure and processes of the organisation and supported by both upper management and individual employees. As such TQM is more a high level philosophy rather than an operational tool itself although it is strongly connected and interdependent with these tools, e.g. JIT and continuous process improvement.³⁹

Only then can be achieved what Toyota said, “Let’s get the product right, then let’s get the quality of the product right, and then when we’ve got the quality of the product right, we’ll find ways to improve the processes used to develop and make the product more effectively and efficiently.”⁴⁰

But even Toyota has experienced the very challenges of maintaining an integrated TQM sustainable over prolonged time periods. As summarised by Robert Spector “there has been a lot of speculation as to causes, with all of the following being mentioned: Managers have been job hopping, engineers not paying attention to basics, top executives too focused on next deal rather than process excellence. Toyota may have lost its discipline by focusing single minded on expanding market share and becoming the number one car manufacturer in the world.”⁴¹

³⁷ Genrich; Erfinden - Wege zur Lösung technischer Probleme;1986
³⁸ Ingenieurbüro Roden; Design for Six Sigma; slide 16
³⁹ Jones; Theory of Strategic Management; p 125-126: TQM
⁴⁰ Shanley; Pharmaceutical Quality and Lessons from Toyota; 2011
⁴¹ Shanley; Tunnell’s Robert Spector with Lessons for Pharma from Toyota; 2011