Cause-and-Effect Diagrams: An impor

Cause-and-Effect Diagrams: An important aspect of process analysis is linking each metric to the inputs, methods, and process steps that build a particular attribute into the service or product. One way to identify a design problem is to develop a cause-and-effect diagram: that relates a key performance problem to its potential causes. First developed by Kaoru Ishikawa, the diagram helps management trace disconnects directly to the operations involved. Processes that have no bearing on a particular problem are not shown on the diagram.The cause-and-effect diagram sometimes is called a fishbone diagram. The main performance gap is labeled as the fish’s “head,” the major categories of potential causes as structural “bones,” and the likely specific causes as “ribs.” When constructing and using a cause-and-effect diagram, an analyst identifies all the major categories of potential causes for the problem. These might be personnel, machines, materials, and processes. For each major category, the analyst lists all the likely causes of the performance gap. Under personnel might be listed “lack of training,” “poor communication,” and “absenteeism.” Creative thinking helps the analyst identify and properly classify all suspected causes. The analyst then systematically investigates the causes listed on the diagram for each major category, updating the chart as new causes become apparent. The process of constructing a cause-and-effect diagram calls management and worker attention to the primary factors affecting process failures. Example 2.3 demonstrates the use of a cause-and-effect diagram by a firm manufacturing air conditioners.