Forum: Reliability & Maintainability Questions and Answers
Topic: Reliability & Maintainability Questions and AnswersTopic Posted by: Reliability & Maintainability Forum (firstname.lastname@example.org )
Organization: System Reliability Center
Date Posted: Mon Aug 31 12:47:36 US/Eastern 1998
Original Message:Posted by: Jim Miller (email@example.com )
Organization:United Defense, L.P.
Date posted: Wed Mar 28 14:16:21 US/Eastern 2001
Subject: Reliability Prediction Confidence Level
We are being asked to provide a confidence level (percent) to our current reliability prediction of a Navy mechanical/electrical/electronics system still in preliminary design. Several areas of the design are still in the "maybe it will be like this" stage. Prediction data sources currently include a mix of handbook, data supplied from hopeful vendors, 217, and Navy / Army failure rate data of similar items we may be using in the new design. Can a confidence level be assigned or calculated at this stage of the prediction, or at any stage of the prediction? If so, is there an established methodology for doing so? We understand that as the design goes forward and actual hardware is specified and tested, and subassemblies are built and tested, we can incorporate vendor data, testing data, FRACAS data, etc. into the prediction, thereby increasing our "confidence" in the prediction. But can this confidence ever be quantified?