A measure of quality that strives for near perfection. A disciplined, data-driven approach and methodology for eliminating defects in any process. Six Sigma started as a defect reduction effort in manufacturing (Motorola Corporation in the mid-1980s) and was then applied to other business processes for the same purpose. Motorola holds the trademark for Six Sigma.
Sigma is a statistical term that measures how far a given process deviates from perfection. The central idea behind Six Sigma is that if you can measure how many "defects" you have in a process, you can systematically figure out how to eliminate them and get as close to "zero defects" as possible. To achieve Six Sigma, a process must not produce more than 3.4 defects per million opportunities. A Six Sigma defect is defined as anything outside of customer specifications. A Six Sigma opportunity is then the total quantity of chances for a defect. A process variation of no greater than Six Sigma is 99,9997% defect free. A 99,9% defect-free level of quality (four sigma) means: 96 crashes per 100.000 airline flights.
Six Sigma methodology: DMAIC (define, measure, analyze, improve, control) is an improvement system for existing processes falling below specification and looking for incremental improvement.
Define a problem or improvement opportunity /Measure process performance /Analyze the process to determine the root causes of poor performance; determine whether the process can be improved or should be redesigned /Improve the process by attacking root causes /Control the improved process to hold the gains. Define high-level project goals and the current process. Measure key aspects of the current process and collect relevant data. Analyze the data to verify cause-and-effect relationships. Determine what the relationships are, and attempt to ensure that all factors have been considered. Improve or optimize the process based upon data analysis using techniques like Design of experiments. Control to ensure that any deviations from target are corrected before they result in defects. Set up pilot runs to establish process capability, move on to production, set up control mechanisms and continuously monitor the process.
Define the project: Define the project’s purpose and scope / Collect background info on the process and customers’ needs and requirements / Develop the charter / Map the processes / Understand the voice of customer. Tools: Affinity diagram, Charter, Communication plan, Control charts, CTQ tree, Kano model, Pareto chart, SIPOC. // Measure the current situation: Gather info on the current situation to provide a clearer focus for the improvement effort / Collect baseline data on defects & their possible causes / Plot defect data over time & analyse for special causes / Do Pareto analysis / Calculate process sigma / Create detailed process maps. Tools: Control charts, Flowchart, Histograms, Pareto chart, Process sigma, Run chart. // Analyze to identify causes: Identify the root causes of defects / Confirm them with data / Develop a focused problem statement / Explore potential causes / Organize potential causes / Collect data / Use statistical methods to quantify a cause and effect relationship. Tools: Brainstorming, Cause and effect diagram, Histograms, Hypothesis testing, Interrelationships digraph, Tree diagram. // Improve: Develop, try out, and implement solutions that address the root causes / Use data to evaluate results for the solutions and the plans used to carry them out / Create possible solutions for root causes / Select solutions / Develop plans / Implement plans / Measure results / Evaluate benefits / Tools: Gantt chart, Brainstorming, Control charts, FMEA, Pareto chart, PDCA cycle, Prioritization matrix, Process sigma, Run chart. Control: Maintain the gains achieved by standardizing the work methods and processes / Anticipate future improvements and make plans to preserve the lessons learned / Develop & document standard practices / Train teams / Monitor performance / Create process for updating procedures / Summarize and communicate learning / Recommend future plans. Tools: Communication plan, Control charts, PDCA cycle, Process management chart, Run chart.
DMADV (define, measure, analyze, design, verify) is an improvement system used to develop new processes or products at Six Sigma quality levels. It can also be employed if a current process requires more than just incremental improvement.
Define design goals that are consistent with customer demands and the enterprise strategy. Measure and identify CTQs (characteristics that are Critical To Quality), product capabilities, production process capability, and risks. Analyze to develop and design alternatives, create a high-level design and evaluate design capability to select the best design. Design details, optimize the design, and plan for design verification. Verify the design, set up pilot runs, implement the production process and hand it over to the process owners. Define design goals that are consistent with customer demands and the enterprise strategy. Measure and identify CTQs (characteristics that are Critical To Quality), product capabilities, production process capability, and risks. Analyze to develop and design alternatives, create a high-level design and evaluate design capability to select the best design. Design details, optimize the design, and plan for design verification. This phase may require simulations. Verify the design, set up pilot runs, implement the production process and hand it over to the process owners.
Six Sigma Methods and Tools : 5 Whys, histograms, Anova Gauge R&R, etc.
Six Sigma Implementation Roles: Executive Leadership includes the CEO and other members of top management. They are responsible for setting up a vision for Six Sigma implementation. Champions take responsibility for Six Sigma implementation across the organization in an integrated manner. They also act as mentors to Black Belts. Master Black Belts, identified by champions, act as in-house coaches on Six Sigma. They devote 100% of their time to Six Sigma. They assist champions and guide Black Belts and Green Belts and ensure consistent application of Six Sigma across various functions and departments. Black Belts operate under Master Black Belts to apply Six Sigma methodology to specific projects. They devote 100% of their time to Six Sigma. They primarily focus on Six Sigma project execution. Green Belts, the employees who take up Six Sigma implementation along with their other job responsibilities, operate under the guidance of Black Belts. Yellow Belts, trained in the basic application of Six Sigma management tools, work with the Black Belt throughout the project stages and are often the closest to the work. /// Black Belts operate under Master Black Belts to apply Six Sigma methodology to specific projects. They devote 100% of their time to Six Sigma. They primarily focus on Six Sigma project execution. Green Belts, the employees who take up Six Sigma implementation along with their other job responsibilities, operate under the guidance of Black Belts. Yellow Belts, trained in the basic application of Six Sigma management tools, work with the Black Belt throughout the project stages and are often the closest to the work.
Lean Manufacturing: Lean is the set of "tools" that assist in the identification and steady elimination of waste (muda). As waste is eliminated, quality improves while production time and cost are reduced. // Toyota: in Lean Manufacturing, focus is upon improving the "flow" or smoothness of work, thereby steadily eliminating mura ("unevenness") through the system and not upon 'waste reduction' per se. Lean implementation is focused on getting the right things to the right place at the right time in the right quantity to achieve perfect work flow, while minimizing waste and being flexible and able to change.
Muda: The original seven muda are: Transportation (moving products that is not actually required to perform the processing) Inventory (all components, work-in-progress and finished product not being processed) Motion (people or equipment moving or walking more than is required to perform the processing) Waiting (waiting for the next production step) Overproduction (production ahead of demand) Over Processing (due to poor tool or product design creating activity) Defects (the effort involved in inspecting for and fixing defects) 7 types of waste [Educational]: Overproduction: products being produced in excess quantity or products being made before the customers need them Waiting: periods of inactivity in a downstream process that occur because an upstream activity does not deliver on time Transport: unnecessary movements of materials (WIP materials) Extra processing: rework, reprocessing, handling, and storage that occur because of defects, overproduction or too much/ little inventory Inventory: excess inventory that is not directly required for the current customer orders e.g.: excess raw materials, finished products, marketing materials that are not mailed or repair parts that are never used Motion: extra steps taken by employees and equipment to accommodate inefficient process layout Defects: products or services that do not conform to specification or to customers’ requirements e.g.: incorrect info listed on a form
Muri: It is all the unreasonable work that management imposes on workers and machines because of poor organization, such as: carrying heavy weights, moving things around, dangerous tasks, even working significantly faster than usual. It is pushing a person or a machine beyond its natural limits.
Mura: It focuses on how the work design is implemented and the elimination of fluctuation at the scheduling or operations level, such as quality and volume;Improving the "flow" or smoothness of work
Lean enterprise: Goals: Improve quality, Eliminate waste, Reduce lead time (the time needed to complete an activity from start to finish), Reduce total costs.
1. Defining the problem // 2. Analysis of Root Causes…Why? // 3. Generate and Test Countermeasure Ideas - Lean methods: Map existing process (information mapping); Reduce stages required (create ideal process map); Change processes from batch to flow (process change); Good housekeeping (reduce inventory); Spring clean once/twice (sweep the backlog); Clean regularly thereafter / Process Map // Query Metrics // Improvement plan 4. Implement the Countermeasures // 5. Check the Result // 6. Standardize the Result // 7. Record the Improvement Story
Problem-solving approach: Form a cross-functional problem solving team from the following departments: ... // Conduct a qualitative process analysis to identify potential causes for ...// Set up a data collection plan ... // Conduct an observational study