Validation of calibration software ? as required by ISO 17025, for instance ? is a topic that folks don? Evil prefer to talk about. Often there is uncertainty about the following: Which software actually must be validated? If that’s the case, who should look after it? Which requirements must be satisfied by validation? How do you take action efficiently and how could it be documented? The following post explains the background and provides a recommendation for implementation in five steps.
In a calibration laboratory, software is used, among other activities, from supporting the evaluation process, around fully automated calibration. Whatever the amount of automation of the software, validation always refers to the entire processes into which the program is integrated. Behind validation, therefore, is the fundamental question of if the process of calibration fulfills its purpose and whether it achieves all its intended goals, that is to say, does it provide the required functionality with sufficient accuracy?
If you need to do validation tests now, you ought to know of two basic principles of software testing:
Full testing is not possible.
Disoriented is always influenced by the environment.
The former states that the test of most possible inputs and configurations of a program cannot be performed because of the large numbers of possible combinations. With respect to the application, the user should always decide which functionality, which configurations and quality features must be prioritised and that are not relevant for him.
Which decision is manufactured, often depends on the second point ? the operating environment of the program. With regards to the application, practically, you can find always different requirements and priorities of software use. There are also customer-specific adjustments to the program, such as regarding the contents of the certificate. But additionally the individual conditions in the laboratory environment, with an array of instruments, generate variance. The wide selection of requirement perspectives and the sheer, endless complexity of the software configurations within the customer-specific application areas therefore make it impossible for a manufacturer to check for all the needs of a specific customer.
Correspondingly, considering the aforementioned points, the validation falls onto the user themself. In order to make this process as efficient as possible, a procedure fitting the next five points is recommended:
The info for typical calibration configurations should be defined as ?test sets?.
At regular intervals, typically one per year, but at 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.
Regarding a first validation, a cross-check, e.g. via MS Excel, may take place.
The validation evidence should be documented and archived.
WIKA offers a PDF documentation of the calculations completed in the software.
Note
For more info on our calibration software and calibration laboratories, go to the WIKA website.