Formal methods have come into wide use because of their effectiveness in verifying %22safety and security%22 requirements of digital systems; a set of requirements for which testing is mostly ineffective. Formal methods are routinely used in the design and verification of high-consequence digital systems in industry. This report outlines our work in assessing the capabilities of commercial and open source formal tools and the ways in which they can be leveraged in digital design workflows.

http://prod.sandia.gov/techlib/access-control.cgi/2014/1420533.pdf

Survey of Existing Tools for Formal Verification

An increasing number of safety-critical systems involve software: this software must not fail. The paper introduces some of the problems of producing safety-critical software, considers the place of software within the total system, and proposes a development methodology. The development ideas are based on principles of error-free development, mathematical formalism, and on independent team for testing.

Software and safety: how compatible are they?

CLAS (C Language Program Analysis System) is a reverse engineering tool intended for use in the verification and validation (V&V) of software programs developed in the ANSI 'C' language. By analysing the source code, CLAS generates data according to two conceptual models of software programs viz, the entity-relationship (ER) model and control flow graph (CFG) model. The tools within CLAS, make use of this data, to provide different graphical views of the programs. We discuss the features provided by CLAS and show how these can aid in automating some aspects of V&V and quality assessment activities.

https://ieeexplore.ieee.org/iel2/4047/11601/00526397.pdf

CLAS: a reverse engineering tool

Within industry, the almost universally accepted method of validating a design against its requirement involves extrapolation from simulation of a (comparatively) small number of test cases to the behaviour of the complete circuit That such an extrapolation is in general unjustifiable is widely accepted, but despite theorem provers' ability to provide a more robust link between specification and circuit design, very few industrial engineers are using theorem provers on a daily basis This paper aims to consider some of the factors that may be preventing the wider application of proof methods Specifically, RSRE has concentrated on two areas of research: the development of a largely automatic but functionally limited proof system, and more recently on a more general prover based on the concepts of a hardware description language It is hoped to illustrate that these provers, being designed specifically for hardware design applications, may provide a more familiar environment for designers wishing to do proofs

Will proof replace simulation

The growing demand for increasingly complex systems, including safety critical systems, is resulting in a tendency to meet this demand by the use of software rather than hardware to implement the increasing functionality. Justifications for this approach include the assumptions that: 

a)

A software system is easier to enhance at a later date




b)

Using software makes it easier to implement complex functions.




c)

It is easier to specify software than hardware.




d)

The cost of replicating a software based system will be lower.

J. T. Webb

Papers

Malpas — Verification of a Safety Critical System