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Goal of Lean Six-Sgma
Design products and processes that do what they are supposed to do with very high reliability.
To remove variability from upstream operations that are inputs to a process in order to yield defect free outputs.
What is Six-Sigma?
Reduction of defects through variability reduction
What is Lean?
To reduce the waste associated with the flow of material and information
Examples of Lean-only Tools?
Setup reduction
Pull scheduling
Continuous flow
What are CTQCs?
Customer requirements are analysed and expressed as Critical to Quality Characteristics ie. the process outputs that really drive customer satisfaction.
Need —> Drivers —> CTQs
What are the benefits of lean six sigma?
Reduced cost Increased market share Improved customer satisfaction Faster time to market Increased revenue and profits
Examples of Six-Sigma-only Tools?
Design of Experiments
Statistical hypothesis testing
Examples of Lean and Six-Sigma Tools?
Error proofing Metrics Fishbone diagram Project management Run chart/spc chart Planning matricies Pareto charts/TPM Scientific method Process mapping
What is the D in DMAIC?
Define the problem, improvement activity, opportunity for improvement, the project goals, and customer (internal and external) requirements.
Project charter to define the focus, scope, direction, and motivation for the improvement team
Voice of the customer to understand feedback from current and future customers indicating offerings that satisfy, delight, and dissatisfy them
Value stream map to provide an overview of an entire process, starting and finishing at the customer, and analyzing what is required to meet customer needs
What is the M in DMAIC?
Measure process performance.
Process map for recording the activities performed as part of a process
Check for process stability
Capability analysis to assess the ability of a process to meet specifications
Pareto chart to analyze the frequency of problems or causes
What is the A in DMAIC?
Analyze the process to determine root causes of variation and poor performance (defects).
Root cause analysis (RCA) to uncover causes
Failure mode and effects analysis (FMEA) for identifying possible product, service, and process failures
Multi-vari chart to detect different types of variation within a process
What is the I in DMAIC?
Improve process performance by addressing and eliminating the root causes.
Design of experiments (DOE) to solve problems from complex processes or systems where there are many factors influencing the outcome and where it is impossible to isolate one factor or variable from the others
Kaizen event to introduce rapid change by focusing on a narrow project and using the ideas and motivation of the people who do the work
What is the C in DMAIC?
Control the improved process and future process performance.
Quality control plan to document what is needed to keep an improved process at its current level
Statistical process control (SPC) for monitoring process behavior
5S to create a workplace suited for visual control
Mistake proofing (poka-yoke) to make errors impossible or immediately detectable
DMAIC vs DMADV?
Define, Measure, Analyze, Design, and Verify (DMADV) is a data-driven quality strategy that focuses on the development of new products or services compared to existing ones. The DMADV method or approach is often used when implementing new strategies because of its basis in data, its ability to identify success early, and its method, which requires thorough analysis. Like DMAIC, it is an integral part of a Six Sigma quality initiative.
What is D (2nd one) in DMADV?
This stage of DMADV includes both a detailed and high level design for the selected alternative. The elements of the design are prioritized and from there a high level design is developed. Once this step is complete, a more detailed model will be prototyped in order to identify where errors may occur and to make necessary modifications.
What is V in DMADV?
Verify
In the final phase, the team validates that the design is acceptable to all stakeholders. Will the design be effective in the real world? Several pilot and production runs will be necessary to ensure that the quality is the highest possible. Here, expectations will be confirmed, deployment will be expanded and all lessons learned will be documented. The Verify step also includes a plan to transition the product or service to a routine operation and to ensure that this change is sustainable.
What are the 5 principles of lean?
- Identify Customers and Specify Value
- Identify and Map the Value Stream
- Create Flow by Eliminating Waste and Achieving a Lot Size of One
- Respond to Customer Pull (where possible)
- Pursue Perfection ie. keep repeating the above steps. Other tools employed in achieving perfection include Kaizen, error proofing, Total Productive Maintenance (TPM) and standardised work.
What is a value stream?
The complete sequence of activities an organisation performs in order to produce and deliver its end product or service. It encompasses suppliers, internal processes, customers and end users
What is a value stream map and what is it compromised of?
Graphical representation of the series of activities the organisation follows in producing and delivering its end product or service. It shows the flow of information and material and the occurrence of actions using easy to understand symbols. It is composed of three parts:
- The flow of material and information from production by suppliers to delivery to customers
- The transformation of the material and information into finished products or services
- The flow of information that supports the first two parts.
When value stream mapping, map the current state map to see the flow of material and information and to identify sources of waste. Then map the future state map as this forms the basis of your lean improvement implementation plan and identifies the specific areas and magnitude of improvement required.
What is flow?
Flow in the process is achieved when the product or service being created progresses through a series of value-added steps without delays defects or non-value-added operations. This means that the product or service moves from the point of production to the point of consumption as quickly as possible. Where there is flow with no waste in the process it is called continuous flow
What are the 8 wastes?
TIM P WOOD
Transportation (unnecessary conveyance)InventoryMotionPeople UnderutilizationWaiting (delays)Over processing (doing extra steps)Overproduction (doing work not requested)Defects (includes rework/repair rime to correct mistakes)
Why 6 sigma (instead of 7, 8 etc)?
3.4 defects per million, beyond that you get diminishing returns (a lot of effort for little gain). Most industries are around 3 sigma instead.
What is COPQ?
Cost of Poor Quality (COPQ) is the cost caused through producing defects.
What is the definition of DPMO or DPPM?
DPMO is Defects Per Million Opportunities and DPPM is Defective Parts Per Million
What is Pareto Principle?
The Pareto principle (or the 80/20 Rule) states that, for many events, roughly 80% of the effects come from 20% of the causes
Name the different kinds of variations used in Six Sigma?
The different kinds of variation are — mean, median, range and mode.
Who forms the part of Six Sigma implementation team?
- Executive leaders
- Champions
- Master black belt
- Black belts
- Green belts
Executive leaders: The decision of to six sigma is taken by the main team – Executive Leaders. They promote the six sigma throughout the enterprise and ensure the commitment of the enterprise in six sigma. The executive leaders are mainly CEO, or some of the board of directors. The six sigma initiative is funded by Executive leaders. The executive leaders should be confident and determine that six sigma will improve organization process and it is succeeded.
Champions: Champions are normally the senior manager of the enterprise. He promotes six sigma mainly among the users of the business. He acts as a coach, mentor, selects projects, decides the objectives, allocates the resources and removes hurdles from black belt players. The champions fight for removing black belt hurdles.
Master Black-Belt: This role highly demands the technical capability in six sigma. All organizations are not started with six sigma and will not have the same. Normally outsiders are recruited for it. The key role of Master Black-belt is train, mentor and guide. He supports the executive leaders in candidate’s selection; teach the fundamentals and train resources and right project for resources.
Black-Belt: Black-belt always leads a selected project team for show casing six sigma. Their responsibilities include finding out the variations and looking after minimizing the variations. Black belt normally selects the projects, train resources, and they are the real implementers of the project. They are the core resources to six sigma as the actual implementation of six sigma is done by black belt, in the enterprise.
Green Belt: The green belt resources supports black belt in the functionality areas. They are part time resources who work mainly on projects for six sigma implementation. The six sigma methodologies for solving problems are applied by green belt and help for defining the basic six sigma implementation of the enterprise. The too support black belt in implementing six sigma in the enterprise.
Can you explain the concept of fish bone/ Ishikawa diagram?
This cause analysis tool is considered one of the seven basic quality tools. The fishbone diagram identifies many possible causes for an effect or problem. It can be used to structure a brainstorming session. It immediately sorts ideas into useful categories.
Methods Machines (equipment) People (manpower) Materials Measurement Environment
What are the 7 basic quality tools for process improvement?
Cause-and-effect diagram (also called Ishikawa or fishbone diagrams): Identifies many possible causes for an effect or problem and sorts ideas into useful categories.
Check sheet: A structured, prepared form for collecting and analyzing data; a generic tool that can be adapted for a wide variety of purposes.
Control chart: Graph used to study how a process changes over time. Comparing current data to historical control limits leads to conclusions about whether the process variation is consistent (in control) or is unpredictable (out of control, affected by special causes of variation).
Histogram: The most commonly used graph for showing frequency distributions, or how often each different value in a set of data occurs.
Pareto chart: A bar graph that shows which factors are more significant.
Scatter diagram: Graphs pairs of numerical data, one variable on each axis, to look for a relationship.
Stratification: The process of dividing a process into subgroups (strata) based on inherent characteristics such as: age group, ethnicity, occupation etc in order to obtain a representative sample for analysis (some lists replace stratification with flowchart or run chart).
What is load testing?
It is the process of putting demand on a software system or computing device and measuring its process
What is the difference between Cpk and Ppk?
Cpk is process capability index, which measures how close a process is running to its specification limits, relative to the natural variability of the process and Ppk is process performance index, which verifies if the sample that have been generated from the process is capable of meeting Customer CTQs (requirements).
What is Cp vs Cpk?
Cp and Cpk measure how consistent you are to around your average performance.
The ‘k’ stands for ‘centralizing factor.’ The index takes into consideration the fact that your data is maybe not centered.
Cpk tells us what a process is capable of doing in future, assuming it remains in a state of statistical control.
Cp assumes the process is centered (i.e. what the ideal can be).
