AbstractÐThis paper examines and proposes an approach to writing software specifications, based on research in systems theory, cognitive psychology, and human-machine interaction. The goal is to provide specifications that support human problem solving and the tasks that humans must perform in software development and evolution. A type of specification, called intent specifications, is constructed upon this underlying foundation. Index TermsÐRequirements, requirements specification, safety-critical software, software evolution, human-centered specifications, means-ends hierarchy, cognitive engineering.

This paper examines the issue of completeness in specification language design. In the mid-80s we identified a set of 26 formal criteria to identify missing, incorrect, and ambiguous requirements for process-control systems. Experimental validation of the criteria on NASA and NASDA spacecraft systems have supported their usefulness in detecting commonly omitted but important information and engineers have been using them in checklist form on real systems. At the same time, we have extended the criteria and now have over 60. This paper shows how most of the criteria can be embedded in a formal specification language in ways that potentially allow automated checking or assist in manual reviews.

This paper examines the management by equipment suppliers of consistency between their product development efforts and the evolution of public standards. We specify structures which make explicit the role of a firm's standards management and provide a unified perspective of its interdependences with other groups, internal and external to the firm. Based on a sample of cases provided by nine standards managers in three firms we develop five standards management structures which are used to provide consistency between product development and public standards evolution. We also show how these structures can be changed systematically with changes in goals and how they are related to three basic building blocks which we refer to as Information Management, Commercial Exploitation and Standard Development. The paper makes two main contributions. First, it enables individuals involved in the design or implementation of a standards strategy to create a simple and realistic visual representation of the binding which channels their activities. Second, it provides a stable framework within which