Refinement is reviewed, highlighting in particular the distinction between its use as a
specification constructor at a high level, and its use as an implementation mechanism at a …

Retrenchment is introduced as a liberalisation of refinement intended to address some of the
shortcomings of refinement as sole means of progressing from simple abstract models to …

Efficient and effective methods are needed to generate defect oriented tests for todays VLSI
circuits. This paper describes an industrial case study for using defect injection and Spice …

For large systems, the manual construction of fault trees is error-prone, encouraging
automated techniques. In this paper we show how the retrenchment approach to formal …

The more obvious and well known drawbacks of using refinement as the sole means of
progressing from an abstract model to a concrete implementation are reviewed …

We review retrenchment as a liberalisation of refinement, for the description of applications
too rich (eg using continuous and infinite types) for refinement. A specialisation of the notion …

KAOS is a goal directed requirements engineering framework based on the decomposition
and refinement of goals. Decomposition and refinement continue until a point is reached at …

Discusses a simple example that demonstrates various expressive limitations of the
refinement calculus, and suggests a liberalization of refinement, called retrenchent, which …

We present a formal characterization of fault-tolerant behaviors of computing systems via
simulation relations. This formalization makes use of variations of standard simulation …

In the formal modelling of safety critical systems, an initial abstract model captures the ideal,
fault free, conception of the system. Subsequently, this model is enriched with the detail …