Chapter 6: Configuration Management

Overview

CM is the discipline that ensures that the state of the software at any given time is known and reconstructable. CM is a discipline that covers hardware as well as software, but in this book CM will be limited to software unless specifically stated otherwise.

CM comprises three basic elements: configuration identification (CID), configuration control (CC), and configuration accounting (CA). While each element may be invoked without the others, CM is incomplete in the absence of any of them.

CID provides a method for specifically and uniquely identifying each instance (e.g., release, version) of a given software product or set of products. By using a standard naming convention that allows for the identification of every instance of the product, each new draft of a document, each new compilation of a unit, or each new build can be specifically identified.

CC is the element that ensures that each change to an instance of the product is known, authorized, and documented. CC includes the activities of the change control board (CCB), which reviews and authorizes changes to the documents and code as increasingly formal control is placed on the developing software system. The software library may also be included as a function of CC.

CA serves to keep track of the status of each instance of the product. This becomes increasingly important as units and modules are integrated into subsystems and systems. It is obvious that the specific parts of a given system must be known so the system itself can be known. CA also assigns and tracks the status of each baseline of the requirements, test, design, code, and so on, as the software effort proceeds. Another growing requirement for CA is the case of a basic product that is adapted for use in multiple installations, each with slight variations in the total requirements set.

The increased use of reusable code makes all CM elements more important than ever.

Figure 6.1 presents an overview of CM processing.

Figure 6.1: CM overview.