Software fault tree analysis services

Ann Marie Neufelder has been constructing software fault trees for 30 years for many different application types. 

Software fault trees should be part of an overall system fault tree since software and hardware failures are generally not independent.  The SFTA is useful when:

The basic software failure events are:

Common mistakes made when doing software fault trees

  • Excluding hardware from the analysis or isolating the software from the rest of the system
  • Starting with "software fails" as the top event
  • Neglecting to use standard failure events and failure modes checklists during the brainstorming
  • Not having the appropriate subject matter experts in the analyses
  • Neglecting to add the "shall nots" divulged from the fault trees into the requirements, design documents and test plans
  • Neglecting to review past historical failure events
  • Performing the analysis too late in development to impact the design