Specification Quality Control

This chapter discusses specification quality control (SQC). The primary purpose of SQC is systems engineering process control through sampling measurement of specification quality. Through SQC, we can improve systems engineering processes, save project time and increase systems engineering productivity. The basic ideas of SQC are simple, which includes "a stitch in time saves nine": fix defects at early design stages (DDP), before they cause damage and/or require a costly “defect removal” process, during test or operation; "An ounce of prevention is worth a pound of cure": learn from defects, which have common underlying causes, and continuously improve your work processes (DPP). Finally, the fact that the SQC process is universally applicable to any readable specification means that any group of people can use it wherever they want control over quality-in-relation-to-standards. Therefore, it needs to use additional methods to see “how good” a specification is and, if necessary, adjust the specification.