2 Change Impact Analysis

Purpose and assessment baseline

Change impact analysis is a structured assessment of how a proposed change would affect an approved project baseline. Its purpose is to give decision-makers evidence to approve, reject, defer, or request revision of a change before work begins.

Assess the request against the current approved scope, schedule, cost, quality requirements, risks, and stakeholder needs. An informal or outdated plan is not the appropriate reference point.

A practical assessment process

Use a consistent process so that the assessment clarifies the request, makes its boundaries explicit, and records the evidence and uncertainty behind its conclusions.

1. Clarify the request. Record what is proposed, why it is needed, its expected benefit, constraints, and assumptions. If the request is unclear, seek clarification before estimating effects.

2. Set the baseline and boundaries. Identify the approved requirements, plans, deliverables, interfaces, and success criteria that may be affected. Trace connections to dependent work and to other teams or systems.

3. Gather evidence. Ask relevant subject-matter experts to estimate the work, review dependencies, and identify uncertainties. Scale the depth of analysis to the change’s size, complexity, and feasibility.

4. Compare options. Consider alternatives such as a smaller change, a later release, or no change. Estimate each option’s effects relative to the same baseline.

5. Record findings and assumptions. Distinguish known effects from estimates. Where precision is limited, include ranges or confidence levels. Document affected plans, rationale, unresolved questions, and the analyst’s recommendation.

Assess connected effects, not only the task that prompted the request. A seemingly small change may also affect interfaces, testing, documentation, procurement, operations, or benefits.

Assessing connected impacts

Examine the dimensions together: an effect in one area can create effects in another. For example, additional testing can increase cost and schedule while reducing quality risk. Make these trade-offs visible rather than treating each dimension in isolation.

Six impact dimensions

Consider the following questions for each area of impact.

Scope

Identify requirements, deliverables, features, or acceptance criteria that would be added, removed, or revised. Assess whether the change alters project objectives, boundaries, or expected benefits, and identify other work products or interfaces that must change.

Schedule

Identify design, implementation, review, testing, approval, and deployment work that would be added or removed. Check affected dependencies and critical-path activities, and determine whether milestones or the completion date would move.

Cost

Estimate additional or avoided costs for labor, materials, equipment, vendors, training, support, and operations. Consider whether rework or delay could create indirect costs. State the estimate’s assumptions and uncertainty.

Quality

Assess possible effects on requirements compliance, acceptance criteria, reliability, performance, usability, safety, and maintainability. Identify new verification, validation, inspection, or testing needs, and consider whether the change could weaken an existing quality target.

Risk

Identify new threats or opportunities and changes in the likelihood or consequence of existing risks. Consider technical, delivery, operational, safety, and external dependencies. Identify mitigations, owners, and residual risk.

Stakeholders

Identify who requests, approves, performs, uses, supports, funds, or is otherwise affected by the change. Assess effects on responsibilities, expectations, training, communications, and adoption. Identify disagreements and groups that need consultation.

Example: adding a portal language

A proposal to add a second language to a customer portal illustrates how the dimensions connect.

• Scope: Identify translation, interface, and revised acceptance-test work.

• Schedule: Check whether localization and testing affect a release milestone.

• Cost: Include translation, development, review, and ongoing content maintenance in the estimate.

• Quality: Add checks for translated content, display layout, and accessibility.

• Risk: Consider inaccurate translations and late content delivery, and identify review and contingency actions.

• Stakeholders: Identify customers, support staff, content owners, and the team responsible for future updates.

Decisions and follow-through

An impact assessment does not automatically decide whether to approve a request. It provides comparable evidence for the authorized decision-maker, who can weigh expected benefits against impacts, constraints, and risk.

If the change is approved, update affected plans and baselines and track implementation. If it is deferred or rejected, record the decision and its rationale. In every case, clear documentation of estimates, assumptions, uncertainty, and dependencies helps make the decision transparent and supports planning for approved work.

• Verification and validation