We propose requirements monitoring to aid in the maintenance of systems that reside in dynamic environments.By requirements monitoring we mean the insertion of code into a running system to gather infor/nation from which it can be determined whether, and to what degree, that running system is meeting its requirements. Monitoring is a commonly applied technique in support of perfonnance tuning, but the focus therein is primarily on computational performance requirements in short runs of systems. We wish to address systems that operate in a long lived, ongoing fashion in non-scientific, enterprise applications.We argue that the results of requirements monitoring can be ofbenejit to the designers, maintainers and users of a system -alerting them when the system is being used in an environment for which it was not designed, and giving them the information they need to direct their redesign of the system. Studies of two commercial systems are used to illustrate and justify our claims.

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Abstract

Adoption of advanced automated SE (ASE) tools would be more favored if a business case could be made that these tools are more valuable than alternate methods. In theory, software prediction models can be used to make that case. In practice, this is complicated by the "local tuning" problem. Normally, predictors for software effort and defects and threat use local data to tune their predictions. Such local tuning data is often unavailable.This paper shows that assessing the relative merits of different SE methods need not require precise local tunings. STAR1 is a simulated annealer plus a Bayesian post-processor that explores the space of possible local tunings within software prediction models. STAR1 ranks project decisions by their effects on effort and defects and threats. In experiments with NASA systems, STAR1 found one project where ASE were essential for minimizing effort/ defect/ threats; and another project were ASE tools were merely optional.

S. FEATHER .USC/lnformation Sciences Institute When a complex system is to be realized as a combination of interacting components, development of those components should commence from a specification of the behavior required of the composite system. A separate specification should be used to describe the decomposition of that system into components The first phase of implementation from a specification in this style is the derivation of the individual component behaviors implied by these specifications.The virtues of this approach to specification are expounded, and specification language features that are supportive of it are presented. It is shown how these are incorporated in the specification language Gist, which our group has developed. These issues are illustrated in a development of a controller for elevators serving passengers in a multistory building.

Abstract

ProgramProgram transformation has been advocated as a potentially appropriate methodology for program development. The ability to transform large programs is crucial to the practicality of such an approach.This paper describes research directed toward applying one particular transformation method to problems of increasing scale. The method adopted is that developed by Burstall and Darlington, and familiarity with their work is assumed.The problems which arise when attempting transformation of larger scale programs are discussed, and an approach to overcoming them is presented. Parts of the approach have been embodied in a machine-based system which assists a user in transforming his programs. The approach, and the use of this system, are illustrated by presenting portions of the transformation of a compiler for a "toy" language.