Validation of calibration software ? as required by ISO 17025, for instance ? is a topic that folks don?t prefer to talk about. Often there is uncertainty concerning the following: Which software actually must be validated? If so, who should take care of it? Which requirements should be satisfied by validation? How can you do it 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 can be used, among other things, from supporting the evaluation process, around fully automated calibration. Whatever the amount of automation of the software, validation always identifies the entire processes into which the program is integrated. Behind validation, therefore, may be the fundamental question of if the process of calibration fulfills its purpose and whether it achieves all its intended goals, in other words, does it provide the required functionality with sufficient accuracy?
To be able to do validation tests now, you should be aware of two basic principles of software testing:
Full testing isn’t possible.
Testing is always dependent on the environment.
The former states that the test of all possible inputs and configurations of an application cannot be performed due to large numbers of possible combinations. With respect to the application, 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 next point ? the operating environment of the program. According to Horror , practically, there are always different requirements and priorities of software use. Additionally, there are customer-specific adjustments to the software, such as concerning the contents of the certificate. But additionally the individual conditions in the laboratory environment, with a wide range 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 your needs of a particular customer.
Correspondingly, taking into account the aforementioned points, the validation falls onto the user themself. To make this technique as efficient as you possibly can, a procedure fitting the next five points is recommended:
The data for typical calibration configurations should be thought as ?test sets?.
At regular intervals, typically once a year, but at the very least after any software update, these test sets ought to be entered in to the software.
The resulting certificates could be compared with those from the previous version.
In the case of an initial validation, a cross-check, e.g. via MS Excel, can take place.
The validation evidence ought to be documented and archived.
WIKA provides a PDF documentation of the calculations completed in the software.
Note
For more info on our calibration software and calibration laboratories, visit the WIKA website.