Rebaseline

Rebaseline is the formal process of establishing a new approved baseline for project scope, schedule, and cost, replacing the existing baseline. Baselines define the agreed milestones, deliverables, budgets, and timelines used to measure performance. A rebaseline is undertaken when the original baseline becomes invalid due to approved changes, significant variances, or external factors, and it requires re-aligning plans, resources, and performance metrics to the new targets.

Rebaselining is typically triggered by substantial changes to requirements, scope growth or reduction, schedule delays, or cost overruns that cannot be adequately controlled within the current baseline. It may also occur after major risk events, regulatory changes, or shifts in project priorities. Any rebaseline usually requires formal approval by a change control board or equivalent governance body and thorough documentation of the rationale, assumptions, and expected impacts.

The process generally includes assessing the impact of the proposed changes, developing a revised plan, obtaining approvals, updating baselines, and communicating the new targets to stakeholders. Key artifacts often updated include the project schedule, work breakdown structure, cost baselines, resource allocations, and risk register. Earned value management and other performance metrics are recalibrated against the new baseline to provide a realistic view of progress and forecasts.

Implications of rebaselining include improved realism and control over the project, but potential loss of historical comparability and increased governance overhead. It is most appropriate in programs with large scope changes or persistent performance issues, ensuring that measurement remains aligned with current objectives. In software and product development, rebaselining may occur when configurations or release plans undergo substantial shifts that justify a new reference point.