Seven Basic Tools of Quality

Kaoru Ishikawa advocated that up to 95% of quality-related problems in the workplace could be solved with these seven fundamental tools. Their power lies in their simplicity and visual nature, which makes them accessible to the entire workforce, not just quality engineers. The Cause-and-Effect Diagram (or Fishbone Diagram) helps identify, sort, and display possible causes of a specific problem. The Check Sheet is a structured form for collecting and analyzing data. Control Charts are used to study how a process changes over time and to determine if it is in a state of statistical control. A Histogram is a graphical representation of the distribution of numerical data. The Pareto Chart, based on the Pareto principle, is a bar graph that shows which factors are more significant. The Scatter Diagram graphs pairs of numerical data to look for a relationship between two variables. Finally, Stratification is a technique to separate data gathered from a variety of sources so that patterns can be seen. Sometimes, a Flowchart is included as the seventh tool to visually map the steps in a process. Together, these tools provide a structured way for teams to collect data, analyze it, identify root causes, and find solutions, forming the backbone of quality circles and shop-floor continuous improvement activities.