Groupware Technology and Software Reuse Position paper for the European Reuse Worskhop (ERW’98).

Computer-Supported Cooperative Work (CSCW) is a research field concerned with the design and implementation of systems to support cooperative work. Such systems are usually called Groupware. Although Software Reusability (SR) is not commonly mentioned as an issue in the CSCW community, there are some obvious overlaps in design issues and methodologies. In this paper I will argue that reusability issues are of particular importance to groupware technology and relate our experiences in this matter. Changing requirements An issue of particular concern in the implementation 1 of groupware is that it is impossible to predict in detail how a system will be used, hence the requirements are at least partially unknown when the system is constructed. Changing requirements is a general problem in software engineering, but in CSCW the problem is more grave than in other domains. In order to adequately support cooperation between people, one needs some understanding of how cooperation takes place. This is a very subtle and not fully formalizable process, as failures of early office automation systems and numerous CSCW studies testify [Suc83, Suc87]. Testing multi-user systems is problematic and can not well be done in a laboratory setting. In the CSCW community it is common knowledge that systems can only be evaluated in situ, at the workplace. Case studies of successful groupware implementations show that systems evolve, as organisations learn to work with them [Orl96, BE96]. If the system is used in a given setting, it affects the way people work and enhances their "technological frame " [Orl92], i.e., their mental model of what the system can be used for, so they think of new ways to use the system. The technical system and the social system evolve in an interlocked process. (Note, however, that presupposes the system to be successful. Many CSCW systems have been installed but were never really used [Gru88]). Consequently, the system has to be reworked over and over again; "maintenance " is not a proper word to describe this, "continuous implementation " is nearer to the mark. "Design for change " is one of the maxims of groupware systems design. But how to do so