SQC

Cause-and-effect diagram, also known as a fishbone diagram, is a tool that systematically organizes results (effects) and causes (factors) in a structure resembling a fish skeleton. This article provides a clear and detailed explanation of the purpose and uses of the cause-and-effect diagram, examples of its application, steps to create one, and key points for extracting causes, illustrated with specific examples.

Control chart is a graph consisting of line data of quality characteristics, center lines, and control limit lines, and is used for the purpose of checking process stability. The structure and meaning of control charts, types and selection of control charts, how to make them, and how to find signs of abnormality are explained from the basics so that even beginners can understand them.

Histogram is a statistical graph that represents the frequency of intervals on the vertical axis and class intervals on the horizontal axis. It is also known as a bar chart or frequency distribution chart. This article explains the benefits of using histograms, six common distribution patterns for interpretation, and how to create them in Excel, with separate instructions for versions before Excel 2013 and from Excel 2016 onward.

Pareto diagram is a composite graph consisting of a bar chart arranged in descending order of value and a line chart showing cumulative composition ratios. This article explains the basic structure of the Pareto diagram, how to create a composite graph in Excel, and key points for analyzing defective items in an easy-to-understand manner for beginners.

We will explain what can be read from check sheets and the characteristics of trends that should be focused on, with examples of consideration.