Distributed con guration management is intended to support the activities of projects that span multiple sites. NUCM is a testbed that we are developing to help us explore the issues of distributed con guration management. NUCM separates con guration management repositories (i.e., the stores for versions of artifacts) from con guration management policies (i.e., the procedures by which the versions are manipulated) by providing a generic model of a distributed repository and an associated programmatic interface. This paper describes the model and the interface, presents an initial repository distribution mechanism, and sketches how NUCM can be used to implement two, rather di erent, con guration management policies, namely checkin/check-out and change sets.

Even though the number and variety of available configuration management systems has grown rapidly in the past few years, the need for new configuration management systems still remains. Driving this need are the emergence of situations requiring highly specialized solutions, the demand for management of artifacts other than traditional source code and the exploration of entirely new research questions in configuration management. Complicating the picture is the trend toward organizational structures that involve personnel working at physically separate sites. We have developed a testbed to support the rapid development of configuration management systems. The testbed separates configuration management repositories (i.e., the stores for versions of artifacts) from configuration management policies (i.e., the procedures, according to which the versions are manipulated) by providing a generic model of a distributed repository and an associated programmatic interface. Specific configuration management policies are programmed as unique extensions to the generic interface, while the underlying distributed repository is reused across different policies. In this paper, we describe the repository model and its interface and present our experience in using a prototype of the testbed, called NUCM, to implement a variety of configuration management systems.

As with any other artifact produced as part of the software life cycle, software architectures evolve and this evolution must be managed. One approach to doing so would be to apply any of a host of existing configuration management systems, which have long been used successfully at the level of source code. Unfortunately, such an approach leads to many problems that prevent effective management of architectural evolution. To overcome these problems, we have developed an alternative approach centered on the use of an integrated architectural and configuration management system model. Because the system model combines architectural and configuration management concepts in a single representation, it has the distinct benefit that all architectural changes can be precisely captured and clearly related to each other---both at the fine-grained level of individual architectural elements and at the coarse-grained level of architectural configurations. To support the use of the system model, we have developed Mae, an architectural evolution environment through which users can specify architectures in a traditional manner, manage the evolution of the architectures using a check-out/check-in mechanism that tracks all changes, select a specific architectural configuration, and analyze the consistency of a selected configuration. We demonstrate the benefits of our approach by showing how the system model and its accompanying environment were used in the context of several representative projects.