Def(Aust) 5679 "The Procurement Of Computer-based Safety Critical Systems"

This safety standard was released as one of the Def(Aust) on August 1998, and encapsulates some of the policies of the Defence Materiel Organisation (DMO) with regards to the procurement, analysis, development, and operation of systems that may be safety-critical.

Even for those not adhering to this safety standard, the management principles and technical principles provide a good overview of aspects which are common to many safety standards

The management principles address the following concepts.

  • Assumption that a system is safety-critical until proven otherwise
  • Issues addressed early and throughout life cycle
  • Visibility of both product and process
  • Diversity of people, skills and techniques
  • Commitment and co-operation of all parties
  • Independence of checking and review
  • Transferrability
  • Auditable and repeatable

The technical principles address the following concepts.

  • Tried and trusted techniques where possible
  • Iterative, continuous and evolutionary process
  • Simplicity of critical functions
  • Isolation of critical functions
  • Use of formal methods for the most critical cases


Although the naming of Def(Aust) 5679 implies that it is applied across Australian defence projects, other safety standards are sometimes applied either with or without it.


Def(Aust) 5679 from the Defence Science Technology Organisation (DSTO) website.