EVIDENCE OUTPUTS
- Trigger catalogue
- Approved rule version
- System acknowledgements
- Exception and backup-expiry record
P04Expire
ARCHITECTURE PATTERN · SYNTHETIC REFERENCE
Retention event engine
Convert approved purpose and lifecycle events into scoped expiry work and verifiable outcomes.
Engineering control
Engineering pattern
not a legal template
WHEN TO USE
Use when retention depends on product events, inactivity, contracts, holds or dependent systems.
Start only after the relevant facts, source status and system boundary are understood.
SOURCE / STATUS BOUNDARY
Verify the legal status before implementation.
Engineering controlPattern verification pointers
These IDs are verification pointers to the primary-source ledger. They are not provision mappings, applicability findings or legal conclusions.
SEQUENCE DIAGRAM
Four accountable hand-offs.
- 01Source system
emits an approved lifecycle event
ARTEFACT · trigger record - 02Rules engine
evaluates scope, period and hold state
ARTEFACT · expiry decision - 03System adapters
delete, anonymise or defer
ARTEFACT · acknowledgements - 04Assurance
samples primary and backup outcomes
ARTEFACT · verification result
TYPED JSON FIXTURE
Synthetic by design.
This example contains no real person, provider, incident or system data. It demonstrates record boundaries, not a production schema.
{
"fixture": true,
"schemaVersion": "1.0-demo",
"pattern": "retention-event-engine",
"subjectRef": "synthetic-only",
"payload": {
"trigger": "purpose_complete_demo",
"ruleVersion": "ret_demo_v2",
"hold": false
}
}THREAT CONSIDERATIONS
- Forged trigger
- Over-broad deletion
- Hold details exposed to unauthorised staff
FAILURE MODES
- A date is calculated from an unreliable event
- Retries create duplicate destructive work
- Derived data and backups remain untracked
RESEARCH / RADAR CONNECTION
Keep implementation context attached.
A small organisation can begin with named owners, a compact inventory and a few tested lifecycle paths while avoiding unsupported readiness claims.
Read Privacy engineering for Indian MSMEs: where simplicity mattersEvent-driven retention
Use approved lifecycle events to trigger scoped expiry workflows.
Promising implementation pattern · Review 2026-10-20Open radar rationaleLOCAL WORKSPACE NOTE
Give this work a next owner.
Nothing is sent anywhere. Avoid names, personal data or confidential incident details.