Reuso griss

Software reuse: From library to factory
by M. L. Griss

Systematic Software reuse is a key business strategy that software managers can employ to dramatically improve their software development processes, to decrease time-to-market and costs, and to improve product quality. Effective reuse requires much more than just code and library technology. We have learned that careful consideration mustbegiven to people, process, and technology. One approachto the systematic integration of these three elements is the concept of the software factory. Hewlett-Packard Co., At we have initiated a multifaceted corporate reuse program to help introduce the best practices of systematic reuse into the company, complemented by multidisciplinary research to investigate and develop better methods fordomain-specific, reuse-based software engineering. This essay discusses our experiences. Key aspects include domainspecific kits, busi:-tess modeling, organization design, and technology infrastructure for a flexible software factory.

Among the many solutions proposed to address this software crisis, the systematicapplication of software reuse to prototyping, development, and maintenance is one ofthe most effective ways to significantly improve the softwareprocess, shorten time-to-market, improve software quality and application consistency, and reduce development maintenance and costs. While many companies are developing proprietary software libraries, software reuse is not yet a major force in most corporate software development. We believe that this is largely because effective reusedepends more on socioeconomic than on technical factors at this time,4,5 while most users still concentrate on library or language technology. In this essay I describe how Hewlett-Packard is directing its efforts to betterunderstand these issues and implement solutions to systematically improve and expand its reuse practice. In folthe lowing sections I highlight the business issues, the growing needfor flexibility, and a more engineered approach to software. I summarize the status and promise of reuse, stressing the integration of improved process, management, and technology. Thelibrarymetaphorand model, used for many years to guide work in reuse, needs to be replaced by a software engineering model based on kits, factories, manufacturing, and engineering. Software engineers and managersneed to change their viewof software reuse from that
"Copyright 1993 by International Business Machines Corporation. Copying in printed form for private use is permitted without payment of royalty provided that (1) each reproduction is done without alteration and (2) the Journal reference and IBM copyright notice are included on the first page. The title and abstract, but no other portions, of thispaper may be copied or distributed royalty free without further permission by computer-based and other information-service systems. Permission to republish any other portion of this paper must be obtained from the Editor.

he phrase software crisis was first used in 1969 to describe the ever-increasing burden andfrustrationthatsoftwaredevelopmentand maintenance haveplaced on otherwise happy andproductive organizations. Since then, managers have been looking for effective strategies to deal with software. Manufacturers of computer systems and instruments, such as Hewlett-Packard Co. and IBM, whose businesses relied mostly on hardware and mechanical engineers, today find that over 70 percent of their research and development engineers working in the areas softare of ware and firmware.Maintenance and rework accountforabout 60 to 80 percent of thetotal software costs. Systems take longer to produce than expected, and software is frequently onthe critical path.

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IBM SYSTEMS JOURNAL, VOL 32, NO 4, 1993

Figure 1 The software trend

70% OF HEWLETPACKARD ENGINEERS PERFORM SOFTWARE DEVELOPMENT

50% OF HEWLETTPACKARDRESEARCH AND DEVELOPMENT PROJECTS INVOLVE SOFTWARE...