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Protocol Plug-and-play starting point Data Integrity

Protocol: Time Control OQ Test Script (Synchronization, Clock Lockdown, Time Zone, DST)

A plug-and-play OQ test script for GxP time controls: verify NTP synchronization and tolerance, a negative test that ordinary users cannot change the clock, controlled-change capture, UTC storage and zone-labelled display, and the daylight-saving edge cases, with expected results and a filled specimen.

Document type: Protocol

Read and copy the template below into your own quality system. It is a generic starting point for your own internal use, provided as is, with no warranty; see the Terms and License. Adopting it does not by itself create compliance.

This is a ready-to-use operational qualification test script for the time controls on a GxP computerized system. It proves the three things time control must deliver: the clock is accurate (synchronized within tolerance), it cannot be changed by ordinary users, and stored/displayed time is unambiguous across sites and daylight-saving transitions. Replace every <<FILL: ...>> placeholder, set your document numbers and dates, and route it through document control and approval. A filled specimen of one executed test case follows. Verify each cited regulation against the current source. This is general guidance to adapt, not legal or regulatory advice.

Approval page

RoleNameSignatureDate
Author (Validation / CSV)<<FILL>>
Reviewer (IT / System Owner)<<FILL>>
Approver (QA)<<FILL>>
FieldEntry
Protocol number<<FILL: PROT-ID, e.g. OQ-TIME-001>>
System / host<<FILL: system name, version, host>>
Version<<FILL: 1.0>>

1. Objective

To verify that the time controls of <<FILL: SYSTEM>> meet the requirements for accurate, protected, and unambiguous time: NTP synchronization within tolerance, restriction of clock and time-zone change to a controlled role, UTC (or local-plus-offset) storage with zone-labelled display, and correct behaviour across daylight-saving transitions.

2. Scope

Server/workstation clock, network time synchronization, OS access controls over time, application-level time storage and display, and DST edge cases. Out of scope: <<FILL: e.g. instrument-side controls tested under the instrument OQ>>.

3. Prerequisites

  • The system is installed and IQ is complete and approved.
  • The NTP hierarchy and tolerance are defined in the configuration specification.
  • A normal (non-privileged) test account and the controlled administrative role are available.
  • The storage/display strategy (UTC recommended) is specified.

4. Roles

RoleResponsibility
TesterExecutes each case, records actual results and evidence.
Reviewer (IT / system owner)Confirms configuration and supports privileged steps.
QAReviews and approves executed protocol and any deviations.

5. Acceptance criteria

All test cases pass as written, or any failure is captured as a deviation, resolved, and re-tested to a pass, before the OQ is approved.

6. Test cases

IDTest stepExpected resultActualPass/FailTester / date
TC-01Read the host’s configured time sourceHost points at the defined internal NTP servers (redundant), not an uncontrolled source<<FILL>><<FILL>><<FILL>>
TC-02Measure clock offset against the referenceOffset within the documented tolerance (<<FILL: e.g. within 2 s>>)<<FILL>><<FILL>><<FILL>>
TC-03Observe a routine correctionCorrection slews (gradual), does not step backward<<FILL>><<FILL>><<FILL>>
TC-04Negative test: as an ordinary user, attempt to change the system clockChange is denied; user has no “change system time” right<<FILL>><<FILL>><<FILL>>
TC-05Negative test: as an ordinary user, attempt to change the time zoneChange is denied<<FILL>><<FILL>><<FILL>>
TC-06As the controlled role, make a small clock correctionChange succeeds and is captured in the secure log with who/old/new/when<<FILL>><<FILL>><<FILL>>
TC-07Inspect a stored record’s time valueStored as UTC or local-plus-offset, never naive local time<<FILL>><<FILL>><<FILL>>
TC-08View a record in the UI and on a printed reportDisplayed time shows its zone label (e.g. UTC or EDT)<<FILL>><<FILL>><<FILL>>
TC-09Cross-site: view the same event from two zonesBoth see correct local time; underlying stored value identical<<FILL>><<FILL>><<FILL>>
TC-10DST autumn: create records spanning the duplicated hourSequence is preserved (correct order in UTC); no ambiguous ordering<<FILL>><<FILL>><<FILL>>
TC-11DST spring: create a record around the skipped hourTime resolves correctly with no invalid or shifted stamp<<FILL>><<FILL>><<FILL>>
TC-12Confirm tz database source and change controlSystem uses IANA tz data (or equivalent) maintained under change control<<FILL>><<FILL>><<FILL>>

7. Deviation handling

Record any failure as a deviation with the observed result and evidence, resolve it (configuration fix, access change), and re-execute the affected case to a pass. QA approves the resolution.

8. Summary and conclusion

State the number of cases executed, passed, and deviated, the disposition of each deviation, and the overall conclusion that time controls are, or are not, qualified. <<FILL: complete at execution>>.

9. Attachments

  • NTP configuration evidence (source list, offset measurement).
  • Screen captures of the denied clock/time-zone change (TC-04, TC-05).
  • The controlled-change log entry (TC-06).
  • Stored-value and display evidence (TC-07, TC-08).

10. References

21 CFR Part 11.10(e) (computer-generated, time-stamped audit trails), 11.10(d) (access control). EU GMP Annex 11 (computerised systems). MHRA GxP Data Integrity Guidance and Definitions (2018). PIC/S PI 041, Good Practices for Data Management and Integrity.

Confirm the current version of each reference before issue.


Filled specimen

One executed test case, illustrative only.

IDTest stepExpected resultActualPass/FailTester / date
TC-04As ordinary user “qc-analyst-3”, attempt to change the system clock from Control Panel and via command lineBoth attempts denied; no “change system time” right heldBoth attempts denied, access-denied message captured (screenshot A-04)PassA. Patel, 2026-06-18

Here the negative test is the one inspectors care about most: an ordinary analyst genuinely cannot move the clock, evidenced by a captured access-denied result, not just an assertion that they cannot.

Common inspection findings this protocol prevents

  • No evidence that the “cannot change the clock” control was ever tested (only asserted).
  • Synchronization proven at go-live with no recorded tolerance or offset.
  • DST behaviour never tested, so an out-of-sequence audit trail surprises everyone later.
  • Naive local time storage never noticed because the stored value was never inspected.

How to adapt this protocol

  1. Set the system, host, and document numbers.
  2. Insert your real NTP source list and tolerance in TC-01 and TC-02.
  3. Add or remove cases to match the system (for example instrument time, database time zone).
  4. Attach the actual evidence for each case; a screenshot of the denied change is the strongest artifact.
  5. Confirm every regulation in section 10 against the current published version before issue.
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