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Lookup NU author(s): Professor Michael Jackson, Emeritus Professor Cliff JonesORCiD
Well understood methods exist for developing programs from given specifications. A formal method identifies proof obligations at each development step: if all such proof obligations are discharged, a precisely defined class of errors can be excluded from the final program. For a class of ``closed'' systems such methods offer a gold standard against which less formal approaches can be measured. For ``open'' systems --those which interact with the physical world-- the task of obtaining the program specification can be as challenging as the task of deriving the program. And, when a system of this class must tolerate certain kinds of unreliability in the physical world, it is still more challenging to reach confidence that the specification obtained is adequate. We argue that widening the notion of software development to include specifying the behaviour of the relevant parts of the physical world gives a way to derive the specification of a control system and also to record precisely the assumptions being made about the world outside the computer.
Author(s): Hayes I, Jackson M, Jones C
Publication type: Report
Publication status: Published
Series Title: School of Computing Science Technical Report Series
Year: 2003
Pages: 16
Print publication date: 01/01/2003
Source Publication Date: 2003
Report Number: 808
Institution: School of Computing Science, University of Newcastle upon Tyne
Place Published: Newcastle upon Tyne
URL: http://www.cs.ncl.ac.uk/publications/trs/papers/808.pdf
