Software reliability in the system context

A systems approach to the analysis and control of software reliability is described which is intended to supplement conventional software reliability models which focus on program attributes under the control of the software professionals. A review of software reliability experience during the operations and maintenance (O&M) phase is presented. This is followed by a description of a basic failure model that supports a unified approach to software and hardware reliability and of the implications of that model for conventional software reliability approaches. Next, the effect of management activities on reliability is investigated, and an outline of a combined hardware/software reliability model suitable for the planning phase is presented.