Complex assurance scenario
LIMS–ERP result interface
Assuring integrity when critical data crosses a system boundary.
Context
Approved laboratory results move from LIMS to ERP and influence material status.
Intended Use
Transfer released lot result and specification status without manual re-entry.
Boundary
Source status, message schema, middleware mapping, retry queue, target status, reconciliation, and support roles.
Failure Chain
A unit field is truncated → ERP interprets a value under the wrong unit → acceptable status is assigned → material is released.
Existing Controls
- Schema validation
- Source-release rule
- Interface exception queue
- Daily reconciliation
Evidence
- Mapping specification
- Boundary-value tests
- Negative-message tests
- Queue recovery demonstration
- Reconciliation challenge
Evidence Gaps
No production alert currently distinguishes delayed from permanently failed messages.
Test Design
Script exact mappings and status rules; explore duplication, reordering, downtime, partial payloads, unusual characters, and delayed recovery.
Decision
Approve after adding an aged-message alert and demonstrating recovery without duplication.
Residual Risk
A novel upstream schema change could evade expected-format checks.
Monitoring
Counts, control totals, message age, rejects, duplicates, and reconciliation exceptions.
Reassessment Triggers
- Schema or middleware change
- New result type
- Unexplained control-total variance
Inspection Questions
- Where is completeness proven?
- Who owns exceptions?
- How is replay prevented from duplicating records?