This is an archived page and is no longer updated.
Please visit our current pages at

Foundations of System Correctness and Failure

Our research in this area looks at some of the philosophical and logical issues behind system correctness - what it means, for example - and system failure, which is somehow the `converse' of correctness. Reasoning about failure tells us much about what it is for a system to be correct, and aircraft accidents are amongst the most carefully investigated incidents of system failure.

These concerns have been addressed in a number of essays collected into a hypertext book, The Success and Failure of Artifacts by Peter Ladkin. The essays consider some of the philosophical and logical questions in the foundations of engineeering, such as: what is the logical situation of specification, requirements, design, software, and digital hardware, with respect to `the world' - or even with respect to each other, as components of an artifact? What can we prove mathematically, and what features stand no chance of being mathematically proven? What does it mean for a system to fail, and how do we tell? Conversely, what does it mean for a system to be `correct'? How can we explain or reason about failure? What are the features of the world that are relevant in considering these questions? What ontology do we need; what reasoning power do we need; what is the logical form of our assertions about systems?

Future planned essays concern the meaning and status of testing; the application of some fundamental engineering terms to behavioral devices such as software; and the meaning of risk. The latter theme has been addressed in Peter Ladkin's lecture Computers and Risk in the section Lecture Notes on the RVS Publications Page.

For investigation and analysis of the failure of complex systems, we look at the area of commercial aircraft accidents. One of the main products of our work here has turned out to be the Compendium on Computer-Related Incidents with Commercial Aircraft, which provides reliable sources of information and commentary on such incidents, as well as resources and links to other sources. Two of our main contributions are

Ladkin has also written surveys, summaries of and introductions to issues in aviation procedures and safety, which may be found in the section Electronic Journalism (Report Series RVS-J) on the RVS Publications Page.

Ladkin is a regular contributor to the RISKS Forum, the Forum on Risks to the Public in Computers and Related Systems, published by the ACM Committee on Public Policy and edited by Peter Neumann of SRI International Computer Science Lab. A list of these articles may be found in the section Electronic Journalism (Report Series RVS-J) on the RVS Publications Page.