7 Quality Tools

7 Quality Tools

Kaoru Ishikawa, a professor of engineering at Tokyo University, developed seven basic tools of quality that may be used to analyse and interpret data. He designed the tools for simplicity. The only one which requires some amount of training is drawing the control charts. Quality pro’s the world over use these tools for quality control. A quality professional must give these tools precedence and excel at them to perfect quality control. Ishikawa argues that a company’s major share of troubles can be worked out using these tools. The Seven Quality Tools can help a manager analyse and prioritise problems effectively, help with information gathering from the collected data and solve problems quickly. Kaoru developed these tools so that even an average person could easily grasp and understand it. These tools have been given many names some of which are the Basic Seven, the Magnificent Seven, etc. These tools are tried and tested, and indispensible to those who have realised its merit. The Seven Quality tools are listed below. Ishikawa Diagram Ishikawa diagram is named after its inventor Kaoru Ishikawa. It is also called as cause-and-effect diagram or fishbone chart as the diagram resembles a fish skeleton. It is a tool used to analyse, sort and determine the various causes of a problem. It shows the relationship between the causes/sub-causes and their outcome. Control Charts These are the most complicated of the seven quality tools. Control charts are graphs used to track changes or progress of a process or product over a particular time period. It displays the data according to the sequence in which it occurred. Checklists Checklists are a structured and systematic form of data analysis and collection. It gathers data such that it’s based on facts rather than assumptions. It can be in various formats, e.g. table, tally chart, etc. Checklists help easy identification of the problem. Pareto Analysis Pareto analysis is also known as the 80:20 rule or ABC analysis. It is one of the simplest yet effective tools available. It is named after its inventor Alfredo Pareto who noticed that very few people controlled most of the nation’s riches. He invented a chart where the vital few could be distinguished from the trivial many. According to this rule 80% of the problems can be attributed to 20% causes. Scatter Diagram A scatter diagram is a graphical tool for the identification of the relationship between two variables. It shows the value of a variable with respect to a change in the other. Two sets of data are plotted on graph, with the x-axis being used for the predictor variable, while the y-axis used for the variable being predicted. This method can be used to test a possible cause/effect relationship. Flowcharts Flow charts are the pictorial representation of a sequence of operations in a process. They are usually simple and easy to understand. They show a step-by-step picture of the process for analysis and discussion. It shows the flow of operations that transform and input to an output for the next step. Histogram A histogram is a bar chart representation of a set of data. It provides an easy way to evaluate the distribution of data. The measurements are grouped into bins, each bin representing a range of values of some variable. It shows patterns that may have otherwise gone unnoticed in a table or chart.