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Fictional worked example · CSVtoCSA editorial

GxP Spreadsheet

Formula, rounding, boundary, protection, version, and independent-verification decisions for a release calculation.

Published 12 September 2026 · Context updated 21 September 2026 · Version 2.0

All organizations, identifiers, test results and decisions in this example are fictional teaching material.

Information available and assumptions

The workbook supports a product acceptance calculation. Approved formulas, units and limits are available independently of the spreadsheet being assessed.

Scope and decision record

Standard case study record

Scope and decision fields

Read these fields before the detailed worked case. All organizations, identifiers, test outcomes, and decisions are fictional teaching material.

GxP Assessment
The workbook calculates a finished-product result used in a regulated batch-disposition decision. Formula, input, version, protection, and review controls are GxP-relevant even though the workbook contains no macros.
Change or Issue
A copied formula references the previous row after a new product range is inserted, and rounding is applied before rather than after the final calculation.
Functions Affected
  • Controlled data entry
  • Formula and reference integrity
  • Rounding and unit rules
  • Independent verification and approved-copy control
Potential Impact
A batch near the acceptance limit could be reported as passing when the approved calculation would fail.
Deviations / Known Issues
The fictional boundary test detects a one-unit rounding difference. Release of the workbook is withheld until the formula is corrected, independently verified, and regression tested.
In this example

Situation

A controlled workbook calculates a finished-product result used by Quality during batch disposition. It has no macros. A new product range and a revised rounding rule are introduced.

Intended Use

Authorized analysts enter approved source values and the workbook calculates a result for qualified Quality review. The workbook does not import raw instrument data or approve the batch.

Failure Scenarios

  • A copied formula references the previous row.
  • Rounding occurs before the final calculation.
  • An analyst uses an uncontrolled local copy.
  • A protected formula cell is overwritten through an unlocked range.

Existing Controls and Evidence

The approved template is stored in a controlled location, formula cells are protected, a second analyst verifies the result, and prior known-answer tests are available. Those records do not cover the new product range or revised rounding rule.

Evidence Gaps and Testing Approach

Review every affected formula and reference. Execute independent calculations, exact known-answer cases, values immediately below, at, and above each limit, invalid and blank inputs, unit challenges, protection checks, version identification, save-and-reopen behavior, and controlled-copy retrieval. Record expected and actual values without masking precision.

Validation Conclusion

In this fictional case, a boundary test exposes premature rounding. The workbook is not released until the rule is corrected, independently verified, regression tested, and approved. Absence of macros is not used as the validation decision.

Reassessment Criteria

Reassess formula, lookup, range, rounding, unit, protection, platform, source-data, intended-use, or approved-location changes.

Limitations and unresolved questions

The conclusion is limited to the assessed workbook, protected formulas and input conditions. No-macro status alone does not reduce the consequences of an incorrect calculation.

Relevant regulations and guidance

These sources apply within their stated scope. The suggested worksheet fields, test designs and fictional decisions are practitioner recommendations, unless a source requirement is expressly identified. Completing a template does not establish compliance.

Computer Software Assurance for Production and Quality Management System Software ↗

Regulatory guidance / GMP guideline · United States · February 2026

Scope: Medical-device manufacturers assuring software used in production or their quality management system.

Relevance: For medical-device production or QMS software, supports selecting assurance activities from intended use, risk and available evidence. It is nonbinding guidance and does not determine other sectors’ obligations.

Status: Final / published · Checked 2026-09-21

Publication identity, scope and status checked against the linked official source. This is not an independent audit of every retained guide statement.

Read source details and applicability →

EudraLex Volume 4, Annex 11 — Computerised Systems ↗

Regulatory guidance / GMP guideline · European Union · January 2011 revision

Scope: Computerised systems supporting activities in the applicable EU pharmaceutical GMP context.

Relevance: For computerised systems used in EU GMP activities, informs lifecycle, supplier and record controls. Confirm applicability to the actual activity; the example does not establish it.

Status: Final / published · Checked 2026-09-21

The Commission index confirms the January 2011 operative revision. The linked PDF could not be retrieved in this check; retained detailed section mappings need review against an authorized copy.

Read source details and applicability →
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