The short answer
Inventory every place the shared code is stored or used, freeze the authorized vendor and job population, provision the approved replacement path, test allowed and denied behavior, communicate the effective boundary, revoke and monitor the old code, then reconcile late jobs, emergency exceptions, and access logs before closure.
Key takeaways
Find the whole shared path
Record access point, code owner, storage locations, dispatch templates, vendor recipients, active work, after-hours process, physical fallback, log coverage, and integrations. Keep the code itself out of the review sheet.
Ask whether the replacement identifies a person, company, job, or time window at the level the operation actually needs.
Use a cutover register
| State | Proof | Failure | Response |
|---|---|---|---|
| Replacement ready | Named/job-bound test succeeds | Vendor cannot complete authorized job | Fix provisioning before revoke |
| Boundary communicated | Audience/version/acknowledgment | Old instructions still circulating | Supersede and search templates |
| Old path revoked | Denied test and system state | Old code still works | Contain and escalate |
| Late/emergency work | Approved exception identity and expiry | Shared path reintroduced informally | Bounded alternative and review |
Monitor for residual use without exposing secrets
Review failed attempts, old template sends, manual notes, and jobs created before the boundary. Distinguish harmless stale documentation from a path that still grants access.
NIST access-control and audit concepts support attribution and review but do not define physical entry authority.
Close with a denied old path and attributable replacement
Name the population, cutoff, evidence version, owner, decision, unresolved exceptions, next checkpoint, and downstream records updated. Preserve the earlier state rather than replacing it with a clean current screen.
Reopen the record when a late event, changed source, new affected item, or downstream consequence invalidates the signed conclusion.
Operational checklist
Mark your progress, then save a working copy. Selections reset when you leave this page. A checked box is not an approval or evidence of completion.
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Edge cases
Sources and references
Follow each source to check the underlying claim. Access checks and professional review are different steps.