Forum Questions and Answers
Topic: PRISM Questions and Answers
Topic Posted by: SRC
Date Posted: Wed Jan 12 8:33:33 US/Eastern 2000
Topic Description: Welcome to the PRISM forum! Please feel free to post your questions and comments about the PRISM assessment software here.
Posted by: Alberto D'Amico
Date posted: Thu Jan 11 7:00:21 US/Eastern 2001
Subject: Duty cycle and calendar hours
Let's suppose we have a product,
-> whose commercial life is 5 years (so 43600 calendar hours).
-> It is plugged for 5 years (so the high voltage part of its Power supply unit works for 5 years with no interruption).
-> It is on (in std-by mode, electronic board on) for -let's say- 2000 hrs every year (so 10000 hrs in its life)
-> It's mechanical part's life have to be 60000 cycles (during the 5 years)
-> If a single cycle lasts 60 seconds then, in the 5 years, there are 1000 fully operational hrs during its life.
In such a situation,
how do I set the duty cycles for the different modules of the product?
how can I read the failure rate coming out from Prism?
Since it is in calendar hours, is it correct to multiply it for the operational/calendar ratio (43600/1000 = 43.6, in our example)?
A last question (sorry to bother you), how the duty cycles and usage profiles are taken into account if they are different within assemblies of the same system, and their conditions are different from the default ones for the system?