Part 105: Quality Improvement Methods
(Project Quality Management: Manage Quality)
- The most common are Plan-Do-Check-Act and Six Sigma
- They do not have a heavy focus on the exam, but Six Sigma has its own certification process
- There are many improvement methods
- Plan-Do-Check-Act (PDCA) Cycle (invented by Shewhart and Deming)
- Kaizen
- Ideas that focus on continuous improvement
- Just-in-Time
- Reduce inventory to just what is needed
- Reduce the cost of carrying the excess inventory
- For example, if you are manufacturing ovens, only stock enough component parts to satisfy demands for a week. You can order more parts every week. This way, you can move to a smaller warehouse, and pay less rent and utilities. And, if you change the design of the oven, you won’t be stuck with extra parts that you can’t use.
- Marginal Analysis
- Every time we improve quality, it costs us money (a high-quality product costs more to manufacture, usually because it takes more time, and labor costs money)
- When we improve quality, we also gain some revenue/profit (customers are happier with a higher-quality product, and we spend less on warranty repairs; also, our reputation improves)
- If the increase in revenue is more than the cost of improving the quality, we are happy, and we try to improve the quality again
- We reach the optimal quality when the incremental revenue from improvements is equal to the incremental costs to obtain it
- That means we can still improve the quality even more, but the cost of improving the quality is more than the benefit
- For example, adding a third coat of paint to a car would make it look better and reduce scratches (customers will be happy and purchase more cars). The increased revenue from car sales is less than the cost of the third coat of paint.
- But if we add a fourth coat of paint, customers won’t notice the difference. The cost of the fourth coat will be more than the revenue we obtain from adding it.
- Total Quality Management (TQM)
- Everybody is responsible for continuously improving quality, whether they are inside or outside the organization
- Invented by Deming
- Quality Function Deployment (QFD)
- Take customer needs and transform them into a product/service
- Six Sigma
- Six Sigma includes DMAIC (Define, Measure, Analyse, Improve, and Control)
- Improves the quality of the output by removing the causes of defects and minimizing variability
- Six Sigma believes that items within six standard deviations (99.99966%) should be free from defects
- Organizations with more defects are spending too much time correcting defects, and therefore do not have enough time to innovate
- Deming Cycle
- Known as A3
- Requires you to define
- Problem
- Current situation
- Root cause of the problem
- Alternative solutions
- Suggestions for a recommended solution
- Cost-benefit analysis
- Kanban
- Pull system that provides sustainable and regular delivery
- Ensures faster delivery, and a sustainable pace of work
- Supports small, continuous improvements
- Four principles
- Start with the existing process
- Respect the existing system’s process, roles, responsibilities, and job titles
- Agree to implement incremental improvements
- Encourage leadership from all levels
- Capability Maturity Model (CMMI)
- Developed by the Software Engineering Institute
- Five levels of organizational maturity (the goal is to reach the fifth level)
- Level One
- Chaos and Panic
- Results are not repeatable
- Level Two
- Project tracking, requirements management, and configuration management processes are present
- Results are repeatable
- Level Three
- Standard development and maintenance processes are integrated throughout the organization
- Training programs ensure compliance
- Level Four
- Organization tracks productivity with metrics
- Performance is predictable
- Quality is high
- Level Five
- Level One
- Organization can focus on continuous process improvement
There are many Quality Improvement Methods