quality management (SOM ch 5)

Here are detailed summary notes based on the Quality Management slides:

Quality Management - Detailed Notes

1. Introduction to Quality Management

• Quality refers to how well a product or service satisfies customer expectations.

• It is crucial for competitiveness, customer satisfaction, and long-term business success.

Two Key Aspects of Quality

1. Quality of Design

   • Determined during the product/service design phase.

   • Focuses on performance, features, reliability, aesthetics.

2. Quality of Conformance

   • Ensures that the product/service meets design specifications.

   • Determined by the production process and consistency in manufacturing.

2. Costs of Quality (COQ)

Quality management involves several costs, categorized as:

A) Prevention Costs (Proactive)

• Costs incurred to prevent defects before they occur.

• Examples:

  • Preventive maintenance of machines.

  • Employee training programs.

  • Supplier quality audits.

  • Product design improvements.

B) Appraisal Costs (Detective)

• Costs related to detecting defects through inspections and testing.

• Examples:

  • Incoming raw material inspections.

  • In-process testing.

  • Final product inspections.

C) Internal Failure Costs (Reactive - Before Delivery)

• Costs incurred when defects are found before delivery to customers.

• Examples:

  • Rework and repair costs.

  • Scrap (discarded defective products).

  • Downtime due to quality issues.

D) External Failure Costs (Reactive - After Delivery)

• Costs incurred when defects are discovered by the customer.

• Examples:

  • Warranty claims and product recalls.

  • Customer dissatisfaction and loss of reputation.

  • Legal liability from defective products.

Key Takeaway:

• Investing in prevention and appraisal reduces internal and external failure costs.

3. Evolution of Quality Management

Quality management has evolved through various approaches:

A) Total Quality Management (TQM)

• A comprehensive approach focusing on continuous quality improvement.

• Based on three key principles:

  1. Customer Focus

  • Understand customer needs and exceed expectations.

  • Improve products/services based on customer feedback.

  2. Employee Involvement

  • Quality is everyone's responsibility.

  • Encourages workers to actively participate in identifying and fixing problems.

  • Quality at the Source (Jidoka): Defects should be corrected immediately.

  3. Continuous Improvement (Kaizen)

  • A mindset of ongoing small improvements rather than large overhauls.

  • Involves identifying waste and inefficiencies.

B) Six Sigma Approach

• A data-driven methodology for reducing defects and process variation.

• Developed by Motorola and expanded by General Electric.

• Aim: Achieve near-perfect performance with no more than 3.4 defects per million opportunities (DPMO).

4. Six Sigma Methodology

Six Sigma follows the DMAIC Framework, a structured problem-solving approach:

Step 1: Define

• Identify the problem and set quality improvement goals.

• Example: Reduce defect rate in manufacturing.

Step 2: Measure

• Collect data to understand current performance.

• Use key metrics like defect rate, process variation, cycle time.

Step 3: Analyze

• Identify the root causes of defects.

• Use tools like Pareto charts, cause-and-effect diagrams (fishbone), and statistical analysis.

Step 4: Improve

• Implement solutions to eliminate defects.

• Example: Modify machine settings, train employees, improve materials.

Step 5: Control

• Maintain improvements by monitoring performance.

• Use control charts and quality monitoring systems.

Key Takeaway:

• DMAIC is a structured method to improve quality and reduce defects.

5. Six Sigma Tools and Techniques

Several tools are used in quality analysis and problem-solving:

A) Control Charts

• Monitors process variation over time.

• Helps detect unusual fluctuations (out-of-control processes).

B) Run Charts

• Tracks trends and patterns in quality performance over time.

• Identifies if process improvements are effective.

C) Pareto Chart (80/20 Rule)

• Identifies the most significant causes of defects.

• 80% of problems come from 20% of the causes.

• Helps prioritize quality improvement efforts.

D) Cause-and-Effect Diagram (Fishbone Diagram)

• Identifies root causes of defects by categorizing potential problem sources.

• Categories: Personnel, Equipment, Materials, Procedures.

Example: Delay in flight departures

• Possible causes: Late cabin crew, mechanical failures, delayed check-in, scheduling errors.

E) Root Cause Analysis

• Systematic approach to finding the underlying cause of defects.

• Uses techniques like 5 Whys Analysis to trace back to the fundamental issue.

6. Six Sigma Quality Standards

• Theoretical Goal: No more than 2 defects per billion opportunities.

• Practical Goal: 3.4 defects per million opportunities (DPMO) to account for process variations.

• Example Calculation:

  • If the acceptable weight of a cereal box is between 19.2 and 20.8 ounces,

  • A Six Sigma process ensures that 99.99966% of the boxes meet this range.

Key Takeaway:

• Six Sigma focuses on reducing variability to improve product quality.