Introduction to Software Configuration Management

Software Configuration Management (SCM) Introduction

• SCM is a set of management disciplines used in software development.
• Critical SCM functions include identification, baseline management, auditing and reporting.

SCM Functions

• Identification: Identifying software configuration items and baselines.
• Baseline management: Managing and controlling baselines created from configuration items. Criteria for baseline definition, building, and management are crucial.
• Auditing and reporting: Ensures the baseline accurately reflects the intended components and that SCM procedures are followed throughout the project.

Software Configuration Management (SCM): Integration and Standards

• SCM integrates all aspects of planning, oversight, and implementation for a software product or project.
• This includes software, user documentation (printed and online), and various media such as CD-ROMs, flash memory, diskettes, tape, EPROMs, and printed documentation.
• ANSI/IEEE standards exist to address SCM, including 828-1998 (which provides guidelines for an SCM plan) and 1042-1987 (a comprehensive overview of SCM with examples suitable for many project types).

SCM Terminology

• Configuration Item (CI) or Software Configuration Item (SCI): Anything associated with a project, like designs, code, test data, documents, etc. Each item usually has unique versions.
• Configuration Control: Ensuring versions of systems and components are recorded and maintained for the lifetime of the system, so that changes are managed and all versions tracked.
• Version: A unique instance of a configuration item that differs from other versions; generally identified by a version number in addition to the configuration item name.
• Baseline: A controlled collection of component versions that make up a complete system; cannot be changed. Used as a reference point.
• Codeline: A set of versions of a software component and co-dependent configuration items from which that component depends.
• Mainline: A sequence of baselines that represent various system versions.
• Release: A version of the system that is ready for use outside the project.
• Workspace: A private area for developers to modify software without affecting other teams.
• Branching: Creating a new codeline from an existing one. Allows independent development.
• Merging: Combining separate versions in different codelines to create a new version of a component.
• System Building: Creating an executable system version by compiling and linking component versions and libraries.

Definitions from IEEE Standard 1042-1987

• Baseline: A milestone in software development, marking the delivery of software configuration items which have been reviewed and agreed upon.
• Software Configuration Item (SCI): Elements treated as a unit for configuration management.
• Configuration: Defines the parts, overall structure and relationships of baselines.
• Configuration Control Board (CCB): Responsible for reviewing and approving changes to baselines.
• Software: Information organized with logical/functional properties throughout development.
• Version: Represents specific instances of baselines or configuration items.

Manufacturing Process

• Building a software product requires a manufacturing-like process involving a bill of materials (BOM), detailed assembly instructions and an exploded parts diagram.
• Software parts needed (like Source code, library routines, executable code, build procedures etc.) are cataloged.
• Procedures and diagrams for software construction are essential.