Constraint-based Software Specifications for Safety-critical Applications

Abstract

Constraint-based specifications add constraints in behavior or properties specifications. If these constraints are violated at run time, appropriate adjustment can be made. This research extends SpecTRM-RL, a newest constraint-based specification language developed by Nancy Leveson, to incorporate graphic representation, augmented assertions, and safety analysis. We also convert portions of the specifications to DFM (Dynamic Flowgraph Methodology) to generate timed fault trees systematically at design stage. These techniques enhance the quality and safety of safetycritical software.