Abstract

Variation is everywhere. All variations have causes, of which there are four types. Common causes are ever-present and best attacked after gathering in-depth information. Special causes are intermittent effects that must be investigated immediately. Other causes are tampering (when unnecessary changes are made in response to common causes) and structural variation (such as seasonal patterns). Statistical control charts with control limits help identify, investigate, and reduce variation. These basics of the theory of variation apply to the management of people. Managers should help their people identify and remove special causes and reduce the occurrence of common causes. Managers should internalize knowledge about variation. One way to do this is to see variation theory in W. Edwards Deming's 14 points. For example, point 1 says to create constancy of purpose. Therefore, frequent goal changing should be avoided.