Validation of calibration software ? as required by ISO 17025, for example ? is a topic that people don?t like to talk about. Almost always there is uncertainty about the following: Which software actually should be validated? If so, who should take care of it? Which requirements should be satisfied by validation? How do you do it efficiently and how is it 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 activities, from supporting the evaluation process, around fully automated calibration. Whatever the degree of automation of the program, validation always refers to the complete processes into that your program is integrated. Behind validation, therefore, is 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 provide the required functionality with sufficient accuracy?
If you need to do validation tests now, you should be aware of two basic principles of software testing:
Full testing isn’t possible.
Testing is always influenced by the environment.
The former states that the test of all possible inputs and configurations of an application cannot be performed as a result of large numbers of possible combinations. Depending on the application, the user must always decide which functionality, which configurations and quality features should be prioritised and which are not relevant for him.
Which Confessions is made, often depends on the next point ? the operating environment of the program. Based on the 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 average person 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 software configurations within the customer-specific application areas therefore make it impossible for a manufacturer to test for all the needs of a specific customer.
Correspondingly, considering the above points, the validation falls onto the user themself. In order to make this process as efficient as you possibly can, a procedure fitting the following 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 into the software.
The resulting certificates could be weighed against those from the prior version.
Regarding an initial validation, a cross-check, e.g. via MS Excel, can take place.
The validation evidence should be documented and archived.
WIKA provides a PDF documentation of the calculations carried out in the software.
Note
For further information on our calibration software and calibration laboratories, go to the WIKA website.