Quality Management Principles and 7QC Tools
Understanding the Concept of Quality
Quality is the measure of how well something fulfills its purpose or meets specific standards and expectations. It is about making sure a product, service, or process is reliable, effective, and satisfying to the person using it.
Factors of Quality
- Performance: How well it works.
- Durability: How long it lasts.
- Appearance: How good it looks.
- Reliability: Consistent performance over time.
- Meeting Expectations: How well it satisfies needs or requirements.
Key Dimensions of Quality
Quality of Design
This refers to how well a product is planned and designed before it is made. It includes factors like features, materials, and specifications. A high-quality design means the product will be useful, durable, and meet customer needs.
Quality of Performance
This is about how well a product works when used. Even if a product has a great design, it must function properly in real-world conditions.
Quality of Conformance
This means how well the actual product matches the original design and standards. If a product is manufactured exactly as planned, it (58) has high quality of conformance.
Costs Related to Quality
The different types of costs related to quality are:
- Prevention Cost (Cost to avoid problems): This is the money spent to stop defects before they happen. It includes training workers, improving processes, and using better materials.
- Appraisal Cost (Cost of checking quality): This is the cost of testing and inspecting products to ensure they meet quality standards.
- Internal Failure Cost (Cost of defects found before selling): This is the cost of fixing defects before the product reaches the customers. It includes rework, scrap, and production delays.
The 7QC (Quality Control) Tools
The 7QC (Quality Control) tools are simple but powerful tools used to find and fix quality problems.
- Check Sheet (for Data Collection): A simple sheet used to record and track defects or issues over time. It helps identify patterns.
- Histogram (for Data Visualization): A bar chart that shows how often different values occur in a dataset. It helps find trends or patterns in quality issues.
- Pareto Chart (for Identifying Major Problems): A special bar chart based on the 80/20 rule; it shows the most common problems, helping focus on the biggest issues.
- Cause and Effect Diagram (Fishbone Diagram): Looks like a fishbone and helps find the root cause of a problem by breaking it into different categories like machines, etc.
- Scatter Diagram (for Finding Relationships): A graph that shows if two factors are related. It helps find cause-and-effect relationships.
- Control Chart: A graph that tracks how a process changes over time. It helps detect unusual variations.
- Flowchart: A diagram that shows the steps of a process in order. It helps find where mistakes happen.
The Deming Wheel and PDCA Cycle
The Deming Wheel, also called the PDCA (Plan-Do-Check-Act), is a simple four-step process for continuous organizational improvement in business. It was developed by Dr. W. Edwards Deming, a quality management expert.
The Four Steps of the Deming Wheel
- Plan: Identify a problem or opportunity and develop a strategy to address it.
- Do: Implement the plan on a small scale to test its effectiveness.
- Check: Analyze the results and compare them with the expected outcomes.
- Act: If successful, standardize the solution and implement it widely; if not, refine the plan and repeat the cycle.