Separation of concerns for dependable software design

Abstract

For ‘mixed-criticality’ systems that have both critical and non-critical functions, the greatest leverage on dependability may be at the design level. By designing so that each critical requirement has a small trusted base, the cost of the analysis required for a dependability case might be dramatically reduced. An implication of this approach is that conventional object-oriented design may be a liability, because it leads to ‘entanglement’, and an approach based on separating services may be preferable.