System Safety Assessment

  Functional Hazard Assessment (FHA)
  Fault Tree Analysis (FTA)
  Failure Mode & Effects Analysis (FMEA)
  Failure Mode & Effects Summary (FMES)
  System Safety Assessment (SSA)
  Common Cause Analysis (CCA)
 ü Common Mode Analysis (CMA)
 ü  Particular Risk Analysis (PRA)
 ü  Zonal Safety Analysis (ZSA)
  Architectural Mitigation Analyses
  DAL Assessments / Justification reports
 

Reliability Engineering

  Reliability Management / Program Office
  Reliability Program Plans
  Reliability Modeling
  Reliability Development & Accelerated-Life
  Failure Rate / Reliability Predictions
  Failure Reporting, Analysis & Corrective Action
  System (FRACAS)

Technical Points / Summary

? Similar to a PSSA but performed later in the program when the design has taken shape and when it has been implemented.  The SSA is used to show that the as designed system complies with the system safety requirements.

? Typically contains:

• the list of safety requirements (including FCs & required probabilities) generated from the FHA and PSSA

• a system description

• verification of the implementation of architectural, protectional and hardware safety requirements into the system design

• a compilation of analyses showing that the qualitative and quantitative system safety requirements have been met, e.g. including FMES, FTA, Table of Compliance (FTA Summary) showing the safety requirements, i.e. FCs, and the quantitative result of each FTA).

•  Common Cause Analysis (usually limited to Common Modes Analysis (CMA) at the system & item levels.  Always includes CMA, Particular Risk (PRA) and Zonal Safety (ZSA) analyses at aircraft level.

• a list of significant latent failures and candidate certified maintenance requirements (CMMRs).

Parnassus has prepared SSAs for several systems comprised of electro-mechanical, hydraulic and electronic equipments flown on several commercial and military jets.