MTBF Calculations tools....

Absolutely right, usually thousands of pounds/dollars. Many years ago I did an spreadsheet that calculated MTBF using the parts count method for three different quality levels and three different envirinments and I fond it very handy. Later I built a DOS PC program which did the same thing and released it as shareware. I got just one £20 registration. I am currently in the early stages of developing a GUI version for Linux.

However, there are two problems I have yet to resolve.

1. The MILSTD parts count method gives very pessimistic results for non military components (which it seems to think are about 30 times more likely to fail than their MILSTD counterparts - an erroneous assumption)

1. Gathering failure rate data for parts and building a library (a somewhat thankless task).

To overcome the first I am thinking of abandoning the quality factor used in the MILSTD parts count method and for the second including just a basic library and facilities to allow users to add there own parts to it (most manufacturers provide the necessary failure rate data).

Ian

Years ago I used a program called "Predictor T-217" by Threshold Systems. I did several projects with it. I called their number and checked the yellow pages with no results so it looks like they went out of business.

You can have my "off-site archive" if you want.

Colin