Report Number: CS-TN-95-26
Institution: Stanford University, Department of Computer Science
Title: Mediation and Software Maintenance
Author: Wiederhold, Gio
Date: October 1995
Abstract: This paper reports on recent work and directions in modern software architectures and their formal models with respect to software maintenance. Related earlier work, now entering practice, provides automatic creation of object structures for customer applications using such models and their algebra, and we will summarize that work. Our focus on maintenance intends to attack the most costly and frustrating aspect in dealing with large-scale software systems: keeping them up-to-date and responsive to user needs in changing environments. We introduce the concept of domain-specific mediators to partition the maintenance effort. Mediators are autonomous modules which create information objects out of source data. These modules are placed into an intermediate layer, bridging clients and servers. These mediators contain knowledge required to establish and maintain services in a coherent domain. A mediated architecture can reduce the cost growth of maintenance to a near-linear function of system size, whereas current system architectures have quadratic factors.