Stale Tooth Review¶
Periodic review — instantiates Ratchet Control and Release Design
A recurring review that re-justifies each aging tooth against present need and prunes the ones whose reason has lapsed, giving the de-ratcheting owner a standing forum to remove.
A Stale Tooth Review is a recurring review in which each aging tooth is put on trial for its continued existence: someone must re-justify it against present need, and any tooth whose justifying condition has lapsed is marked for removal. Its defining move is condition-triggered re-justification by a named owner — it does not wait for a pre-set expiry date; it periodically asks, of every existing tooth, "does the reason for this still hold?", and it gives the de-ratcheting owner a standing forum and mandate to prune. It differs from a sunset register, which stamps a fixed expiry at a tooth's birth, by judging teeth on current relevance rather than the calendar. It is where removals are decided and queued, not executed.
Example¶
An enterprise has accumulated access entitlements for a decade: employees change roles, projects end, contractors leave — but their permissions persist, because granting access is a same-day ticket and revoking it is nobody's job. The identity-governance team institutes a quarterly Stale Tooth Review, in the form of an access recertification: every entitlement above a sensitivity threshold is presented to a named owner (the resource owner or the holder's manager), who must affirmatively re-justify it against the holder's current role, or it is flagged for revocation. In the first cycle, 31% of privileged entitlements turn out to have no current justification — the project ended, the person moved — and are queued for removal. The review does not strip the access itself; it produces the adjudicated worklist and, crucially, puts a named owner on the hook for each keep-or-cut call, so "we'll sort out access someday" becomes a quarterly decision with an accountable signer.
How it works¶
- Re-justify against present need. Each tooth must earn continued existence now; silence or a lapsed justification means it is flagged, not grandfathered.
- Trigger on cadence, judge on condition. The review runs on a schedule, but a tooth's fate turns on whether its reason still holds — not on a birth-date expiry.
- Assign a named owner per tooth. Every keep-or-cut decision has an accountable signer, so removal gains a sponsor the way addition always had one.
- Produce a worklist, don't execute. It adjudicates and queues; a sprint or gate carries out the removals.
Tuning parameters¶
- Review cadence — quarterly, annually; frequent reviews keep staleness low but cost owner attention.
- Scope threshold — which teeth are reviewed (all, or above a sensitivity/impact line); broader is thorough, narrower is sustainable.
- Default on non-response — if an owner does not re-justify, does the tooth stay or go? Revoke-on-silence is aggressive and effective; keep-on-silence is safe and toothless.
- Evidence bar — how much proof of continued need is required; higher removes more but burdens owners.
When it helps, and when it misleads¶
Its strength is that it directly attacks teeth that outlived their reason, and by putting a named owner on each decision it manufactures the removal sponsorship that ratchets structurally lack — the standard cure for privilege creep and the operational form of least-privilege maintenance.[1]
Its failure mode is rubber-stamp recertification, in which overwhelmed owners re-approve everything to clear the queue, so the review runs forever and removes nothing. It also cannot see teeth no one thought to enroll, and a keep-on-silence default quietly defeats it. The classic misuse is running the review for compliance-audit optics while the default and the owner incentives ensure nothing is actually cut. The discipline that guards against this is to default to revoke-on-silence, sample re-approvals for realness, and measure the review by teeth removed, not teeth reviewed.
How it implements the components¶
sunset_decay_or_review_rule— the periodic re-justification of each tooth against present need is the review flavor of this rule.de_ratcheting_owner— assigning a named, accountable owner to each keep-or-cut decision gives pruning the sponsor it structurally lacks.
It judges teeth on current relevance, not on a pre-set clock, so it does not maintain the birth-stamped expiry register (temporary_exception_registry — that's Sunset Clause Register, the time-triggered counterpart to this relevance-triggered review). It decides removals rather than carrying them out.
Related¶
- Instantiates: Ratchet Control and Release Design — it is the standing forum where accumulated teeth are re-justified or cut.
- Consumes: Ratchet Event Log — the ledger of teeth it reviews.
- Sibling mechanisms: Add/Remove Symmetry Audit · Cumulative Impact Budget · De-Escalation Gate · De-Ratcheting Sprint · One-In/One-Out or Cap Rule · Ratchet Event Log · Ratchet Threshold Dashboard · Sunset Clause Register · Rollback Runbook
Editorial Notes¶
Form Classification¶
Form family: Assessment, Review & Assurance
Rationale: Stale Tooth Review operates as a bounded evaluation of existing evidence or work that produces a finding or disposition because it a recurring review that re-justifies each aging tooth against present need and prunes the ones whose reason has lapsed, giving the de-ratcheting owner a standing forum to remove.
Independent corroboration: The frozen evidence defines Stale Tooth Review as 'A recurring review that re-justifies each aging tooth against present need and prunes the ones whose reason has lapsed, giving the de-ratcheting owner a standing forum to remove', so its operative form is Assessment, Review & Assurance.
Review outcome: Independent reviewer agreement; high confidence.
Origin Attribution¶
Primary origin: Organizational & Management Science
Origin pattern: Cross-disciplinary synthesis
Present-day reach: Universal
Rationale: Periodic removal of obsolete ratcheted commitments is organizational de-escalation governance.
Related originating lineages:
- Law & Governance — Legal doctrine, regulatory governance, and procedural accountability supplies a parallel or contributing lineage for the mechanism's defining operation: a recurring review that re-justifies each aging tooth against present need and prunes the ones whose reason has lapsed, giving the de-ratcheting owner a standing forum to remove.
- Systems Thinking & Cybernetics — Pruning interrupts accumulation feedback.
Review resolution: The blind reviewers agree that organizational_management is the primary origin and differ only on reported ambiguity, alternate origin disagreement, origin mode disagreement. I preserve every independently explained alternate from both records rather than imposing a numeric cap. I retain cross_disciplinary_synthesis because the combined evidence shows material contributions from several lineages. The broader reach of universal records portability separately from historical provenance; encyclopedia_synthesis=true preserves the affirmative synthesis judgment where either reviewer identified one.
Attribution caveat: The named tooth metaphor is encyclopedic, while periodic de-ratcheting has organizational and legal-governance analogues.
Encyclopedia synthesis: The exact catalogued form synthesizes established practice rather than reproducing a single standard historical label.
Review outcome: Reconciled after independent review; medium confidence.
References¶
[1] Saltzer, Jerome H.; Schroeder, Michael D.. "The Protection of Information in Computer Systems". Proceedings of the IEEE 63(9): 1278–1308 (1975). States the least-privilege principle: every program and user should operate with only the privileges needed to complete the task. registry ↩ Show verification details
Supported in partVerified against the publisher's abstract
Abstract only: the paper sets out protection design principles, but the held abstract never states least privilege, so it frames the claim at most.
“Section I describes desired functions, design principles, and examples of elementary protection and authentication mechanisms.”