Reliability based quality (RBQ) technique for evaluating the degradation of reliability during manufacturing

Abstract

Complex, modern day aviation systems such as Army helicopters require much more than sophisticated performance and versatility. Such systems demand high levels of field reliability to render their operation both safe and cost effective. To meet this need, a total life cycle reliability program is required — one that does not stop after design and development but continues through production and field use. Only through a total life cycle program that is executed by well disciplined engineering methods and procedures, can safe, reliable, and economical helicopter systems be achieved. In order to assure that helicopter systems and components are reliable and cost-effective, a comprehensive methodology is being developed by the U.S. Army Aviation Research and Development Command (AVRADCOM). The basic framework for developing the methodology is defined in AVRADCOM's R&M management guidebook (1). The entire range of reliability engineering efforts as they relate to all phases of a helicopter's life cycle are covered in the guidebook. This paper addresses the production phase, which historically contributes to helicopter unreliability, and which traditionally has had no detailed reliability engineering procedures. It discusses how to assess and control the reliability of a helicopter system or component as it leaves production, by performing reliability and quality control analyses that account for production degradation factors due to manufacturing induced defects and imperfect inspection.