Chapter 19
Continual Improvement Method with Six Sigma, Lean, and Lean Six Sigma
Objectives
• After reading the chapter and reviewing the materials presented the students will be able to:
• Understand the rationale for continual improvement.• Understand management’s role in continual improvement.• Identify improvement needs.• Develop improvement plans.
Rationale for Continual Improvement
• Continual improvement is fundamental to success in a global environment.
• Customer needs are not static, they change continually.
• The only way a company can hope to compete in the modern marketplace is to improve continually.
Management’s Role in Continual Improvement
• Establish an organization wide quality council and serve on it.• Work with the quality council to establish specific quality
improvement goals with timetables and target dates.• Provide necessary moral and physical support. Physical
support comes in the form of resources needed to accomplish the quality improvement objectives.
• Schedule periodic progress reviews and give recognition where it is deserved.
• Build continual quality improvement in the regular reward system, including promotions and pay increases.
Essential Improvement Activities
• Maintain communication: Communication is essential to continual improvement.
• Correct Obvious Problems: In such cases, the problem should be corrected immediately.
• Look upstream: Look for causes, not symptoms.• Document problems and progress: It is not uncommon for an
organization to continue solving the same problem over and over again because nobody took the time to document the problems that have been dealt with and how they were solved.
• Monitor changes: Because the solution may not solve the problem or only partially solve the problem.
Structure for Quality Improvement
• Establish a quality council: The quality council has overall responsibility for continual improvement. It should include executive level decision makers.
• Develop a statement of responsibilities: Formulating policy as it relates to quality, setting benchmarks, establishing the team and project selection process, provide necessary resources, implementing the project, monitoring progress, and implementing reward and recognition program.
• Establish the necessary infrastructure: Subcommittees that are assigned specific duties, project improvement teams, quality improvement managers, quality training program, and a structured improvement process.
The Scientific Approach
• The scientific approach involves making decisions based on data, looking for the root cause of problems, developing appropriate solutions, and planning and making changes instead of relying on short term fixes.
• Meaningful data are free from errors of measurement and procedure.
• Too many attempts are made to solve symptoms rather than problems.
Identification of Improvement Needs
• Apply multi voting: Multi voting involves using brainstorming to develop a list of potential improvement projects. Team members vote several times to decide which projects to work on first.
• Identify customer needs: Identify pressing customer needs and use them as projects for improvement.
• Study the use of time: If excessive amount of time is devoted to a given process, problem, or work situation, this could signal a trouble spot.
• Localize problems: Problems tend to be like roof leaks in that they often show up at a location far removed from the source.
Development of Improvement Plans
• The first step is to develop a mission for the team. This statement should clearly define the team’s purpose. 5 stages in the plan:
• 1. Understand the process: Before attempting to improve a process, make sure every team member thoroughly understands it.
• 2. Eliminate errors: In analyzing the process, the team may identify obvious errors that can be quickly eliminated.
• 3. Remove slack: Analyze all the steps in the process to determine if there are steps that could be done a better way, or whether they need to be done at all.
• 4. Reduce variations: Common causes result in slight variations and are almost always present. Special causes result in greater variations and are not always present.
• 5. Plan for continual improvement: Each time a problem or potential improvement is identified, an improvement plan is developed (plan), implemented (do), monitored (check), and refined as needed (adjust).
Common Improvement Strategies• Describe the process: To make sure that everyone involved in improving a process has a
detailed knowledge of the process.• Standardize the process: To continually improve a process, all people involved in its operation
must be using the same procedures – best, most effective, and most efficient. • Eliminate errors in the process: This strategy helps delete steps, procedures, and practices
that are being done a certain way simply because that is the way they have always been addressed.
• Streamline the process: This can be done by reducing inventory, reducing cycle times, and eliminating unnecessary steps.
• Reduce sources of variation: Can often be traced to differences among people, machines, measurement instruments, material, operating condition, and times of day. After the source has been identified, this information should be used to reduce the amount of variation to the absolute minimum.
• Bring the process under statistical control: Special causes are eliminated and a plan for continual improvement is developed.
• Improve the design of the process: Through experimentation. What factors do you want to improve? What factors are going to be measured (cycle time, yield, finish, etc)? Measure the critical factors. Analyze the results. Act on the results.
Additional Improvement Strategies• Group Technology: With group technology, processes are arranged so that work
flows in a U shaped configuration. This can result in less time in material handling, and less floor space use.
• Synchronized Production: Synchronized production involves synchronizing the needs of the production line with suppliers of the material needed on the line.
• Jidoka: Jidoka means halting an entire process when a defect is discovered so that it will not cause additional problems further down the line.
• Cost Curves: A cost curve shows graphically how much cost accumulates until the consumer is billed for the product. The tool helps managers economize on the handling of orders.
• Mushroom concept: This is done by holding to standard processes as long as possible in the overall production cycle and adding different features only at the end of the process so that a variety of diversified products mushroom out at the end.
Kaizen
• Kaizen is the concept of continual improvement of people, processes, and products.
• Management are responsible for allocating resources necessary for kaizen to work, and promoting kaizen.
• Supervisors are responsible for improving communication in the workplace, maintaining morale, providing coaching, soliciting suggestions from employees, and making kaizen suggestions.
• Employees are responsible for participating on teamwork activities, making kaizen suggestions engaging in continual self improvement activities, enhancing skills through education and training, and cross functional training.
Goldratt’s Theory of Constraints
• Goldratt defines a constraint as anything that limits an organization from achieving higher performance.
• Goldratt’s theory is based on the assumption that every organization faces constraints.
• Identify the constraint. Exploit (turn into positive factor, eliminate, or circumvent) the constraint. Subordinate (constraint has greatest priority) everything else to exploit the constraint. Eliminate the constraint. If so, return to first step and continue the improvement process.
The CEDAC Approach
• CEDAC is an acronym for cause and effect diagram with the addition of cards. Three conditions must be present for continual improvement to occur:
• A reliable system: For continual improvement to occur there must be a standardized, reliable system.
• A favorable environment: The keys are leadership and education. Leadership includes commitment to continual improvement and allocation of resources. Education involves employees becoming skilled in the use of improvement system.
• Practicing as teams: It is important for team members to practice together because work is performed by teams.
Six Sigma Concept• The purpose of Six Sigma is to improve the performance of processes to the point
where the defect rate is 3.4 per million or less.• It was designed for use in high volume production settings.• The central core of Six Sigma concept is the six step protocol for process
improvement.• 1. Identify the product characteristics wanted by customers.• 2. Classify the characteristics in terms of their criticality.• 3. Determine if the classified characteristic are controlled by part and/or process.• 4. Determine the maximum allowable tolerance for each classified characteristic.• 5. Determine the process variation for each classified characteristic.• 6. Change the design of the product, process, or both to achieve a Six Sigma
process performance.
Lean Operations
• Lean means doing more with less and doing it better.• Lean is about getting the right things to the right
place at the right time and in the right amounts.• At the heart of the concept are the reduction of
waste and the improvement of work flow.• Lean focuses on reducing and ideally eliminating:
overproduction waste, inventory waste, motion waste, Transportation waste, over processing waste, defects waste, waiting waste, and underutilization waste.
Lean Six Sigma
• Lean is a continual improvement method that focuses on reducing waste and improving process flow.
• Six Sigma is a continual improvement method.• Lean Six Sigma combines the best of these two concepts.• One of the strengths of Lean Six Sigma is its emphasis on
preparation of the key personnel (Green Belts, Black Belts, Master Black Belts, and Champions) who will be responsible for its deployment and ongoing operation.
• This preparation, coupled with well defined roles for individuals adds to the potential for continual improvement methods.
Summary• Continual improvement is fundamental to success in a global environment. • Management’s Role in Continual Improvement: Management needs to work with the quality council to establish specific
quality improvement goals with timetables and target dates.• The scientific approach involves making decisions based on data, looking for the root cause of problems, developing
appropriate solutions, and planning and making changes instead of relying on short term fixes.• Multi voting involves using brainstorming to develop a list of potential improvement projects. Team members vote several
times to decide which projects to work on first.• Study the use of time: If excessive amount of time is devoted to a given process, problem, or work situation, this could
signal a trouble spot.• Localize problems: Problems tend to be like roof leaks in that they often show up at a location far removed from the
source. • Group Technology: With group technology, processes are arranged so that work flows in a U shaped configuration. This can
result in less time in material handling, and less floor space use.• Mushroom concept: This is done by holding to standard processes as long as possible in the overall production cycle and
adding different features only at the end of the process so that a variety of diversified products mushroom out at the end.• Kaizen is the concept of continual improvement of people, processes, and products.• Goldratt defines a constraint as anything that limits an organization from achieving higher performance.• The purpose of Six Sigma is to improve the performance of performances to the point where the defect rate is 3.4 per
million or less.• Lean means doing more with less and doing it better.• Lean Six Sigma combines the best of these two concepts.
Home Work
• Answer Questions 1,2, 6 on page 515.• 1. Explain the rationale for continual improvement.• 2. What is management’s role in continual
improvement?• 6. What is multi voting, and how is it used?
