David Parnas Prof. David Lorge Parnas, P.Eng.
Serious errors can hide for years.
Consequently, many are hesitant to employ software in safety-critical applications and all companies are finding the cost of correcting and improving software to be an increasing burden. This talk describes a procedure for inspecting software that consistently finds subtle errors in software that was believed to be correct. Reviewers exploit the hierarchical structure of the code rather than proceeding sequentially through the code. Reviewers focus on small sections of code, producing precise summaries that are used when inspecting other such sections. Reviewers proceed systematically so that no case, and no section of the program, gets overlooked.