Validation of calibration software ? as required by ISO 17025, for example ? is a topic that people don?t prefer to talk about. Often there is uncertainty about the following: Which software actually must be validated? If so, who should look after it? Which requirements must be satisfied by validation? How does one take action efficiently and how is it documented? The following post explains the background and gives a recommendation for implementation in five steps.
In a calibration laboratory, software is used, among other things, from supporting the evaluation process, up to fully automated calibration. Regardless of the amount of automation of the program, validation always refers to the complete processes into that your program is integrated. Behind validation, therefore, may be the fundamental question of whether the procedure for calibration fulfills its purpose and whether it achieves all its intended goals, that is to say, does it supply the required functionality with sufficient accuracy?
To be able to do validation tests now, you ought to know of two basic principles of software testing:
Full testing is not possible.
Testing is always influenced by the environment.
The former states that the test of most possible inputs and configurations of a program cannot be performed due to the large numbers of possible combinations. According to digital pressure gauge , the user should always decide which functionality, which configurations and quality features should be prioritised and which are not relevant for him.
Which decision is made, often depends on the second point ? the operating environment of the software. Depending on application, practically, there are always different requirements and priorities of software use. There are also customer-specific adjustments to the software, such as regarding the contents of the certificate. But also the individual conditions in the laboratory environment, with a wide range of instruments, generate variance. The wide variety of requirement perspectives and the sheer, endless complexity of the program configurations within the customer-specific application areas therefore make it impossible for a manufacturer to test for all your needs of a specific customer.
Correspondingly, taking into account the aforementioned points, the validation falls onto an individual themself. To make this process as efficient as possible, a procedure fitting the next five points is recommended:
The data for typical calibration configurations ought to be defined as ?test sets?.
At regular intervals, typically once a year, but at the very least after any software update, these test sets should be entered in to the software.
The resulting certificates could be compared with those from the prior version.
In the case of an initial validation, a cross-check, e.g. via MS Excel, may take place.
The validation evidence ought to be documented and archived.
WIKA offers a PDF documentation of the calculations completed in the software.
Note
For further information on our calibration software and calibration laboratories, go to the WIKA website.