This is a help for calculating the reliability of series/parallel and non- series/parallel systems. ( project document - PDF )
(Current version only supports up to 20 modules.)

Please follow the instructions below step by step: (click here for samples)

1. Input the configuration of the system.

According to the system structure, please input the parameters and configuration in the first input window. (Click here to learn more about the syntax of the configuration description)

2. Now you have three choices:

a.  If you only want the general result

Click the first RUN (Get Expression of Reliability), then you will get the diagram of system structure and full expression of system reliability.

b. If you want the numerical result

Please input the numerical value of reliability for each module in the second window, then click the second RUN (Get Reliability), you will get the diagram of system structure and the full expression of reliability, also you will get the numerical value of system reliability. (Click here to learn more about how to input the numerical value)

c. If you want to input the failure rate of each module

Please input the numerical value of failure rate for each module in the third window, then click the third RUN (Get Graph or Reliability), you will get the diagram of system structure, the full expression of reliability. If you choose Graph Only,  you will also get the diagram of system reliability R(t) vs time. If you choose Value Only, you will also get the numerical result of the system reliability at the fixed time which you input. (Click here to learn more about how to input the failure rate)

3. There are 3 typical examples. Please look at these examples carefully and see how it works.

example 1 --- simple series system
example 2 --- simple parallel system
example 3 --- a series/parallel system

example 4 --- a non-series/parallel system

If you still have any problems, please contact me at bwu@ecs.umass.edu