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 should be validated? If that’s the case, who should look after it? Which Destiny must be satisfied by validation? How does one take action efficiently and how is it documented? The following blog 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, around fully automated calibration. Regardless of 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, 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 due to the large number of possible combinations. With Skill to the application, the user should always decide which functionality, which configurations and quality features must 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. With respect to the application, practically, there are always different requirements and priorities of software use. Additionally, there are customer-specific adjustments to the program, 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 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 the needs of a particular customer.
Correspondingly, considering the above 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 defined as ?test sets?.
At regular intervals, typically one per year, but at least after any software update, these test sets ought to be entered into the software.
The resulting certificates can be weighed against those from the prior version.
In the case of a first 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, visit the WIKA website.