THE CUMULATIVE EFFECT OF PREVENTION

Quality costs have been discussed widely in the literature. This discu ssion has not always agreed and it is possible to identify two basic s chools of thought; one asserts the existence of a minimal level of qua lity cost for a given level of prevention and appraisal activities, an d the other asserts that through prevention quality improvement is con stant. This paper summarises these positions and outlines a behaviour model of quality costs that unifies and clarifies them. The behaviour model is based on the consideration of the cumulative effects of preve ntion. Ceteris paribus, continuous prevention activities should permit quality improvements whilst at the same time reducing the costs neces sary to obtain them. The behaviour model introduces the effect of exte rnal quality requirements in an attempt to explain how, over time, qua lity improvement efforts do not necessarily result in decreased qualit y costs as customers' quality requirements rise over the same period.