Annex A.2.5: OpsCon: justification and nature of changes
The section explains why the change is needed and what kind of change it is.
What annex A.2.5 asks
The section explains why the change is needed and what kind of change it is. It covers the justification for the change, the nature of the change, the assumptions and constraints, and the relationship to the current system. It is the bridge between the current situation in A.2.4 and the proposed system in A.2.6.
Annex A is normative content and part of a full conformance claim.
Why it matters
The justification is where the concept earns its funding. The clause expects the reason, not only the description. The nature of the change distinguishes an evolution from a replacement, which changes the risk profile and the migration plan.
No clause level change is public for this unit; the DIS keeps the title and scope, and the requirement text is not released.
What good looks like
Write the justification in terms of the problem from the business or mission analysis. Describe the change type and the assumptions. Link each assumption to the risk register or the decision it affects.
Evidence an assessor asks for
The assessor will ask what happens if the project does nothing. The justification has to answer that question, not only describe the new system.
- Justification The problem or opportunity and why the change is the preferred response
- Nature of change Evolution, replacement, extension or retirement, with the boundary of the change
- Assumptions and constraints Each assumption and constraint, with its source and its effect on the concept
- Relationship to current system What is retained, replaced, migrated or retired
Where it commonly fails
- The justification is a list of features with no problem statement
- The change is described as new without saying what happens to the current system
- Assumptions are not recorded, so the migration plan rests on unstated beliefs
What to do before the revision
Write the do-nothing case in one paragraph. If it is acceptable, the justification is not yet strong enough.
Read across
- A.2.4 OpsCon: the current system or situation
- A.2.6 OpsCon: concepts for the proposed system
- 6.2.1 Purpose: business or mission analysis
- 6.2.3.3 Define the problem or opportunity space
← A.2.4 OpsCon: the current system or situation A.2.6 OpsCon: concepts for the proposed system →
Source for annex A.2.5: ISO/IEC/IEEE 29148:2018, Annex A.2.5, retrieved 19 October 2026. The revision note rests on ISO page 94091. The requirement, evidence and gaps are written from our record. Every source.