Outline of Method
The main steps in the Parts Stress Analysis method are as follows:
1. Define the proposed system and develop a reliability model.
2. For each block (or area) within the model:
a. List each part comprising the item(s) represented by the block.
b. Determine the mean operating stress levels for each part and hence the factors appropriate to its particular failure rate model. (See Data Tables.)
c. Calculate the failure rate of each part using the appropriate model.
d. Sum the failure rates to give the total failure rate for the block (or area).
Evaluate the block (or area) reliability.
3. Combine the block (or area) reliabilities as shown by the reliability model to obtain the total system reliability.
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Some blocks in the model may have to be evaluated separately, e.g., one-shot devices, items whose reliabilities are not time-dependent or constant with time, etc.).
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