ClearCase

Foundations

Software Configuration Management (SCM)

The discipline of controlling and tracking changes to software artifacts — versions, baselines, and configurations — over a project's life.

ClearCase

IBM Rational's enterprise SCM and version control system for managing source code and other artifacts across teams.

Version Control

Tracking and managing changes to files over time so history is preserved and versions can be retrieved or compared.

Why SCM Matters

SCM enables parallel development, reliable builds, traceability, and safe change management on complex projects.

Core Concepts

VOB (Versioned Object Base)

A ClearCase repository that stores versioned files, directories, and their history.

View

A workspace that presents a specific set of file versions to a user, determined by configuration rules.

Dynamic View

A view that provides transparent, real-time access to versions in VOBs without copying files locally.

Snapshot View

A view that copies selected versions to a local disk for work offline or with better performance.

Element and Version

An element is a file or directory under version control; each change creates a new version in its history tree.

Versioning

Version Tree

The branching history of an element showing all its versions and branches over time.

Check Out / Check In

Reserving an element to modify it (check out) and committing the change as a new version (check in).

Labels

Named tags applied to versions to mark baselines or releases for easy identification.

Branching

Branch

A parallel line of development that lets teams work on features or fixes independently.

Branching Strategy

A planned approach to using branches (e.g., per release, feature, or developer) to organize parallel work.

Merge

Combining changes from one branch into another, resolving conflicts where versions diverge.

Conflict Resolution

Deciding how to reconcile competing changes when merging, using ClearCase's diff and merge tools.

Configuration

Config Spec

A set of rules in a view that selects which versions of elements the view sees, defining its configuration.

Baseline

A known, labeled configuration of versions used as a stable reference point for builds or releases.

Build Auditing (clearmake)

ClearCase's ability to record exactly which versions and steps produced a build for reproducibility.

Workflows

UCM (Unified Change Management)

ClearCase's higher-level process layer that organizes work into activities and streams, often integrated with ClearQuest.

Stream and Activity (UCM)

A stream is a UCM branch structure for a team or developer; an activity groups the changes for a task.

Integration with ClearQuest

Linking code changes to change requests and defects for traceability across development.

Parallel Development

Multiple developers or teams working simultaneously on isolated branches, then integrating changes.

Best Practices

SCM Best Practices

Frequent integration, clear branching strategy, meaningful labels/baselines, and traceable changes for reliable delivery.