The preservation of the stored data of the activities performed shall be ensured, including the preservation of readability. It must also be protected against unwanted modifications.

Calculations and data transfer must be subject to appropriate checks on a systematic basis, so as to ensure that they are fit for use.

When software developed by laboratory personnel or by an external technician is used, it must be documented in sufficient detail and validated. For this purpose, if appropriate, a technical document, or a technical annex in the corresponding procedure, shall be prepared. The software validation documentation should include the requirements, the validation protocol used, the acceptance criteria, the tests and results, the conclusions as to whether or not it fits the intended use, and the user’s manual.

The commercial software is considered sufficiently validated but if, in the use of this tool, variables or modifications are introduced by the technical personnel that may induce calculation errors or errors in the transfer or loss of information, they must also be validated and documented.

The use of spreadsheets or other applications that allow the design of formulas or algorithms shall be protected against accidental modifications by means of locking or password protection. They shall also be identified, and there shall be control of the version in use, and if a new validation is required after a new edition.