Preparing Functional Safety
Achieving functional safety for a software-based system is not trivial; it is a long and costly process that should not be undertaken lightly, but one that can bring in enormous returns.
As with any important project, the first order of business should be ...
Defining Sufficient Dependability
A system’s dependability is its ability to respond correctly to events in a timely manner, for as long as required; that is, it is a combination of the system’s availability (how often the system responds ...
Establishing Good Processes
A good process does not guarantee that the system being built with that process will achieve the required level of functional safety. It does not even guarantee that the system will be a good one.
With a poor process it ...
Establishing Methods of Validation
A standard requirement for certification of a system’s safety integrity level (SIL) is that the system’s functional safety characteristics be measured, validated and ...
Building Functional Safety
Validation demonstrates only that a system does (or does not) meet defined dependability standards. Functional safety must be build into a system from the start, and all work to this end should follow from the premise that all software contains faults and ...
Validating Functional Safety
After taking all possible care to ensure that functional safety is designed and built into a software system (that, for instance, deadlines and other pressure did not cause anyone to make mistakes or deliver shoddy work) the system is not ...
Conclusion
In Part II we have seen that functional safety should be designed and built into a software system from its inception. It begins with the best available expertise and a clear definition of the system’s dependability ...
