Systems Effectiveness Associates, Inc.
20 Vernon Street
Norwood, MA 02063
Phone: 781-762-9252
Fax: 781-769-9422

Reliability Analysis

Availability Prediction Tool

Please follow the directions below to calculate the following values:
System Availability
System MTTF
Hours of System Outage per Year

1. Input the data as blocks of similar modules.
2. More than one type of redundancy can be associated with a type of module within a block as long as the total number of modules in a block does not exceed six.
3. For each module block:
Enter the Module Type, the Failure Rate, the MTTR and the Mean Service Time.
Then, add as many redundancy code entries for that block of modules as you wish.
Make sure that there is the correct number of slots filled to match the redundancy code. If the system has 3 of 4 redundancy you should fill 4 slots.
4. Once finished with each block of modules, click the Add Block button to save that block and continue adding more. You may enter as many blocks as you wish.
5. Once you have completed entering the redundancy data for your last block, and before you click Add Block button, click the Enter Mid-Plane button to enter the Failure Rate, MTTR and Mean Service Time for the Mid-Plane.
6. Click the calculate button and the results will be displayed at the top of the page.

Module Type Failure Rate (fpmh) MTTR (hours) Mean Service Time (hrs)
Redundancy Type Code
None N
1 of 2 1
2 of 3 2
3 of 4 3
Slot # Redundancy Code

Please call SEA, Inc. for evaluation of more complicated configurations.

To download a MicroSoft Excel version of this Availability Prediction Tool, Click here.