Applying the Seven Basic Quality Tools in Software Development

Ishikawa’s Seven Basic Tools for Quality Control Checklist (or Check Sheet) – to facilitate gathering data and to arrange data so it can be easily used later Pareto Diagram – a frequency chart of bars in descending order; the bars are usually associated with types of problems Histogram – a graphic representation of frequency counts of a sample or a population Scatter Diagram – portrays the relationship of two interval variables; can make outliers clear Run Chart – tracks the performance of the parameter of interest over time; used for trend analysis Control Chart – an advance form of a run chart for situations in which the process capability can be defined Cause and Effect Diagram (fishbone diagram) – it shows the relationship between a characteristic and the factors that affect that relationship

Ishikawa’s Seven Basic Tools for Quality Control

Checklists Summarize the key points of the software development process More effective than lengthy process documents Help ensure that all tasks are complete and the important factors or quality characteristics of each task are covered Examples of checklists are: Design review checklist Code inspection checklist Moderator (for review and inspection) checklist Pre-code-integration checklist Entrance and exit criteria for system tests Product readiness checklist

Pareto Diagram Identifies areas that cause most of the problems

Pareto Analysis of Software Defects

Pareto Diagram of Defect by Component Problem Index

Histograms

Profile of Customer Satisfaction with a Software Product

Scatter Diagram of Program Complexity and Defect Level

Correlation of Defect Rates of Reused Components Between Two Platforms

Grouping of Reused Components Based on Defect Rate Relationship

Pseudo-Control Chart of Test Defect Rate—First Iteration

Pseudo-Control Chart of Test Defect Rate—Second Iteration

Pseudo-Control Chart of Inspection Effectiveness

Cause-and-Effect Diagram

Cause-and-Effect Diagram of Design Inspection

A Schematic Representation of a Relations Diagram

A Diagram of Complex Relationships Associated with Customer-Critical Situations of a Software Product