How much Reliability

Individually, we may be concerned about a smal portion of the reliability program, Such as probability of success, or economic considerations, or systems effectiveness, or one of the many other reliablility factors, when we should be looking at the whole picture. Reliability is not something that you buy by the piece or pound erdezem and just attach to the equipment, it is something that is inherent in the disian. This places a great responsibility on the design engineer. He must know the safety factor of each and every part, how they can fail, and how to compensate for all the variables. There is no part answer to ``how much reliability;'' it involves many trade-offs, and the final decision will be made as a result of these trade-offs. When figuring ``how much reliability,'' we must consider the routin engineering practices, then add how much it would cost using good reliability practices. Afte this is determined, one must assign a useful Iife span to the equipment, determine the cost of maintenance, the cost of owning the equipment, and the cost of idle equipment. From this informtion, good decisions can be made. There is no quick ans wer to ``how much reliability,'' but it can easly be evalupted and the determination, made.