Lecture on Scatter Diagrams and Quality Management Tools

Introduction

• Topic: Scatter Diagrams
• Context: Part of the seven basic quality tools (7QC)
• Links to related content:
  1. Article on scatter diagrams
  2. Playlist of all 7QC tools
  3. Playlist on quality management knowledge area

Understanding Scatter Diagrams

• Purpose: To figure out the relationship between two different kinds of data
• Comparison:
  • Use bar charts or histograms for single data types
  • Use scatter diagrams for two different data types
• Terminology: Scatter diagrams are also known as scatter charts

Example of Use

• Scenario:
  • Collaborating with a testing team to create new test cases
  • Aim: To determine the impact of new test cases on the number of defects found
• Data Representation:
  • Vertical axis: Number of defects found (e.g., 5, 10, 15)
  • Horizontal axis: Number of passed test cases (e.g., 5, 10)
• Observation in Diagram:
  • At 10 passed test cases, about 31 defects were found
  • As passed test cases increase to between 30 and 35, defects found decrease significantly

Conclusion from Example

• Relationship Found:
  • As the number of passed test cases increases, the number of defects found decreases
  • A clear relationship was established using the scatter diagram

Importance

• Utility: Determining if a relationship exists between variables
• Impact on Testing:
  • Establishing relationships can lead to reduced defects in future tests
  • Helps teams agree on strategies to improve testing outcomes

Conclusion

• Final Notes: Scatter diagrams are essential in quality management for visualizing relationships between variables, particularly in testing scenarios.

This lecture provided valuable insights into scatter diagrams and their application in improving quality management processes.