Arc Skills / Configuration and change control
Review a deviation or waiver request
Use Arc Skills to review a request to depart from a controlled engineering requirement. Get a comparison of the requested scope, actual evidence, downstream consequences and information the authorized reviewer needs to decide.
Use this skill
Use Arc Skills to review this deviation or waiver request.
Inputs:
- Project definitions and approval criteria
- Exact requirement, departure and configuration scope
- Measurement evidence, uncertainty and proposed controls
Return a decision table with supported facts, missing evidence, affected obligations and reviewer options. Preserve the requested scope and original criterion. Identify the authorized disposition; do not invent approval.What you provide and what you get
| What you have | How it is used | What you get |
|---|---|---|
| Project terminology and controlled criterion | Interpret the requested departure | Correct scope and decision basis |
| Observed results and configuration | Compare like-for-like evidence | Supported departure and uncertainty |
| Controls and downstream requirements | Assess consequences and recurrence | Reviewer options and evidence gaps |
A mass departure applies to one article, not the whole fleet
Illustrative engineering example.
The project calls acceptance of an existing departure a waiver. This example concerns one instrument serial number with a measured mass above its allocated limit.
REQ-M rev C: instrument mass shall not exceed 12.0 kg in delivery configuration.
Article SN-04: 12.3 kg ±0.1 kg under the supplied bounded measurement interpretation.
Requested waiver: SN-04 only. System budget claims spare capacity, but its current ledger is not attached.
Proposed control: identify the article and update its mass-properties record.| Decision aspect | Supplied evidence | Finding | Required reviewer evidence / option |
|---|---|---|---|
| Requirement departure | 12.3 ±0.1 kg versus 12.0 kg | Even the lower bound, 12.2 kg, exceeds the limit | Record the nonconformance against REQ-M C |
| Scope | Instrument SN-04 only | Request is bounded to one article | Identify delivered configuration and prevent automatic extension to other serial numbers |
| System mass consequence | Narrative claim of spare capacity | Current system budget absent | Obtain the controlled ledger including this article and reserves |
| Mass properties | Total mass result only | Center of gravity and inertia consequences unresolved | Provide the relevant mounting/load and mass-properties checks |
| Disposition | Article labeling and record update proposed | These controls identify the departure but do not establish acceptability | Reviewer can request more evidence, reject or accept under explicit authorized scope |
The measured departure is supported here because the whole supplied interval exceeds the limit. The existence of that departure does not by itself determine the waiver disposition: the authorized reviewer still needs the system-level consequences.
A note in the delivery record controls traceability; it is not a physical mitigation for excess mass. The review distinguishes identifying the affected article from demonstrating that its use remains acceptable.
Separate the departure from its acceptability
- Use the project’s actual deviation and waiver definitions and approval route.
- Compare the exact criterion and configuration with results, units and uncertainty.
- Bound serial, lot, duration and operating conditions; assess linked effects.
- Present supported reviewer options and the evidence required for each disposition.
Questions about this task
Are deviation and waiver used the same way on every project?
No. Read the project’s contractual definitions and approval process before classifying the request. The engineering comparison still needs an exact criterion and bounded scope.
Sources and further reading
- NASA Systems Engineering Handbook: configuration management: Background on identifying configurations and controlling baseline changes.
References inspected on 3 October 2026. The worked output is an authored example using the stated inputs.