SRC Forum - Message Replies

Forum: Reliability & Maintainability Questions and Answers

Topic: Reliability & Maintainability Questions and Answers

Topic Posted by: Reliability & Maintainability Forum ( )
Organization: System Reliability Center
Date Posted: Mon Aug 31 12:47:36 US/Eastern 1998

Back to message list Show all replies Topics List About this forum
Original Message:

Posted by: John Schweighardt ( )
Organization:BAE SYSTEMS-CNI
Date posted: Thu Jun 28 11:43:37 US/Eastern 2001
Subject: Spares Calculator
I have been using an old Lotus spares calculator (15 years), but it's been acting up lately. Is there a good, Windows-based software package available out there? I've been unsuccessful in my search. Thanks

Previous reply

Subject: Actuarial method for spares calculations
Reply Posted by: Larry George ( )
Organization: Problem Solving Tools
Date Posted: Fri Jul 20 15:52:23 US/Eastern 2001
Please refer to for software specification for actuarial forecasts. Actuarial forecasts are used by the US Air Material Command and airlines for service and spares planning for high cost, fracture critical parts like engines and major engine modules. The software specification doesn't mention it, but I also estimate the distribution of forecast demand, for recommending stock levels. Using the real distribution obviates the need for the Poisson assumption in the Air Force actuarial method and the normal distribution assumption used elsewhere. Spreadsheet versions are available. Please request my article, "Forecasting for the Automotive Aftermarket," for more information. Reliability statistics,, allow actuarial methods to be used for ALL parts, not just those tracked by serial number. If you like, send field data, and I will send back nonparametric estimates of age-specific field reliability and failure rate functions, actuarial forecasts, and their distributions, FREE.

Reply to this message