Six Sigma is one of the most important and popular developments in the quality field. It has saved huge amounts of money and improved the customer experience for a large number of organizations across the world, yet it is applied in an inconsistent and often reductive fashion in many companies.
Chapter 10 Principles of Six Sigma Key Idea Introduction Although we view quality improvement tools and techniques from the perspective of Six Sigma, it is important to understand that they are simply a collection of methods that have been used successfully in all types of quality management and improvement initiatives, from generic TQM efforts, to ISO 9000, and in Baldrige processes Six Sigma A simple quality metric An overall strategy to quality improvement SixSigma Metrics Defect – any mistake or error that is passed on to a customer Defects per unit (DPU) = number of defects discovered number of units produced Defects per million opportunities (dpmo) = DPU 1,000,000 opportunities for error SixSigma Quality Ensuring that process variation is half the design tolerance (Cp = 2.0) while allowing the mean to shift as much as 1.5 standard deviations, resulting in at most 3.4 dpmo kSigma Quality Levels Six Sigma (Chapter 3) Based on a statistical measure that equates to 3.4 or fewer errors or defects per million opportunities Pioneered by Motorola in the mid 1980s and popularized by the success of General Electric Key Idea (Chapter 3) Six Sigma can be described as a business improvement approach that seeks to find and eliminate causes of defects and errors in manufacturing and service processes by focusing on outputs that are critical to customers and a clear financial return for the organization Key Concepts of Six Sigma (1 of 2) (Chapter 3) Think in terms of key business processes, customer requirements, and overall strategic objectives Focus on corporate sponsors responsible for championing projects, support team activities, help to overcome resistance to change, and obtaining resources Emphasize such quantifiable measures as defects per million opportunities (dpmo) that can be applied to all parts of an organization Key Concepts of Six Sigma (2 of 2) (Chapter 3) Ensure that appropriate metrics are identified early and focus on business results, thereby providing incentives and accountability Provide extensive training followed by project team deployment Create highly qualified process improvement experts (“green belts,” “black belts,” and “master black belts”) who can apply improvement tools and lead teams Set stretch objectives for improvement Key Idea Problem Solving A structured problemsolving process provides all employees with a common language and a set of tools to communicate with each other, particularly as members of crossfunctional teams DMAIC Methodology Define Measure Analyze Improve Control Define Describe the problem in operational terms Drill down to a specific problem statement (project scoping) Identify customers and CTQs, performance metrics, and cost/revenue implications Measure Key data collection questions – What questions are we trying to answer? – What type of data will we need to answer the question? – Where can we find the data? – Who can provide the data? – How can we collect the data with minimum effort and with minimum chance of error? Analyze Focus on why defects, errors, or excessive variation occur Seek the root cause 5Why technique Experimentation and verification Improve Idea generation Brainstorming Evaluation and selection Implementation planning Control Maintain improvements Standard operating procedures Training Checklist or reviews Statistical process control charts Tools for SixSigma and Quality Improvement Elementary statistics Advanced statistics Product design and reliability Measurement Process control Process improvement Implementation and teamwork Design for Six Sigma Focus on optimizing product and process performance Features – A highlevel architectural view of the design – Use of CTQs with welldefined technical requirements – Application of statistical modeling and simulation approaches – Predicting defects, avoiding defects, and performance prediction using analysis methods – Examining the full range of product performance using variation analysis of subsystems and components Six Sigma in Services and Small Organizations Six Sigma is equally applicable to services. However, services have some unique characteristics Key Idea Six Sigma in Services All Six Sigma projects have three key characteristics: a problem to be solved, a process in which the problem exists, and one or more measures that quantify the gap to be closed and can be used to monitor progress Key Six Sigma Metrics in Services Accuracy Cycle time Cost Customer satisfaction Lean Production and Six Sigma The 5S’s: seiri (sort), seiton (set in order), seiso (shine), seiketsu (standardize), and shitsuke (sustain). Visual controls Efficient layout and standardized work Pull production Single minute exchange of dies (SMED) Total productive maintenance Source inspection Continuous improvement Traditional Economic Model of Quality of Conformance Total cost Cost due to nonconformance “optimal level” of quality Cost of quality assurance 100% Modern Economic Model of Quality of Conformance Total cost Cost due to nonconformance Cost of quality assurance 100% ... 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