Worst Case Analysis
How Worst Case Circuit Analysis Saves $$$
Worst Case Circuit Analysis (WCCA or WCA) is a cost-effective means of screening
a design to ensure with a high degree of confidence that potential defects and deficiencies
are identified and eliminated PRIOR TO and DURING test, production, and delivery.
WCCA is not an after-the-fact exercise but a cost-effective integral part of the design process.
WCCA is not a candidate for elimination when there are cost overruns.
When a WCCA is performed properly, the results often save companies millions of
dollars in lost revenue, dramatically lessen the possibility of human disaster,
and avert potential disasters, both monetary and political.
Conducting a WCCA during the design phase should be a top consideration. The computer
models should be constructed in parallel with the breadboards and/or EM’s. The models
should be reviewed and updated for EVERY circuit or requirement change.
Should you do a WCCA? Here are some questions to ask yourself:
• How much risk can the program accept?
• What is the cost of failure?
• What is the heritage of the circuitry?
• What is the cost of doing or not doing a worst case analysis?
The typical cost of performing a rigorous WCCA is generally less than 1% of the
program cost. The cost of not doing the WCCA can be 100% of the program cost.
We have seen many program failures which required at the least, major redesigns
AFTER completion of qualification testing. This costs enormous amounts of time and
money.
Benefits From WCCA
•
Validate acceptable operation throughout the entire product life cycle under the most unfavorable combination of anticipated conditions [Worst Case Extreme Value Analysis (EVA)]
•
Define Critical Components and Spec. Control Drawing (SCD) Limits
•
Provide Acceptance Test Procedure (ATP) Limits
•
Define Need for and Range of Select-At-Test (SAT) components
•
Improve Reliability through Parts Stress and Derating Analysis
•
Identify design concerns which during test, alignment, and use, could result in circuit damage or premature degradation.
WCCA helps ensure increased product reliability. We accomplish this through rigorous
mathematical and simulation-based models, along with hardware correlation. Correlated
models are then used to determine part stress margins, and EOL/BOL product operating
specifications. A single over-stressed component can cost your company millions
of dollars. A thorough Worst Case Analysis can prevent this from happening.
Background & Definition
A Worst Case Circuit Analysis is a quantitative
assessment of the equipment performance, accounting for manufacturing, environmental
and aging effects. In addition to a circuit analysis, a WCCA often includes a stress
and derating analysis, a Failure Modes and Effects Criticality analysis (FMECA) and a Reliability
Prediction (MTBF).
The specific objective is to verify that the design is robust enough to provide
operation which meets the system performance specification over the design life under
worst case conditions and tolerances (initial, aging, radiation, temperature, etc.).
Links to more Background Information can be found HERE.
Do You Need a Worst Case Circuit Analysis?
Have a question? As WCCA experts, we are here to help.
AEi Systems supports WCCA for the Automotive, Space, Nuclear, Medical, and other high reliability industries.
We are happy to discuss part tolerances, mission life, specifications, reliability, failure, radiation, and SDRL related questions along with any other project requirements.
If you have any questions about WCCA or need to find out more about our Worst Case Analysis services please contact AEi Systems via email, info@aeng.com, or by phone at (310) 216-1144.
In order to provide a firm fixed quotation for a WCCA, we will need to see a schematic of the design, a parts list (BOM), and a specification, if one exists.
Please let us know if a Non-Disclosure (NDA) needs to put into place. If so, please forward a Mutual NDA Form in MS Word Format to lee@aeng.com. AEi Systems can also send its mutual form to you if that is preferred.
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• EB Aerospace
• EDO/AIL
• FEI
• Florida Power and Light
• FORD
• Frequency Electronics
• General Dynamics
• Hamilton Standard
• Harris
• Honeywell
• Hughes Space and Communications
• International Rectifier
• Interpoint
• ITT Industries
• L3
• Linear Technology
• Lockheed Martin (CA, CO, PA)
• Lucix
• Merrimac
• MIT Lincoln Labs
• Moog
• M.S. Kennedy/Anaren
• Neptec
• Northrop Grumman
• Perkin-Elmer/Excelitas
• Raytheon
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