Validation of calibration software ? as required by ISO 17025, for instance ? is a topic that people don?t like 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 requirements should be satisfied by validation? How do you do it efficiently and how could it be 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 activities, from supporting the evaluation process, up to fully automated calibration. Regardless of the degree of automation of the software, validation always identifies the entire processes into that your program is integrated. Behind validation, therefore, may be the fundamental question of whether 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?
If you want to do validation tests now, you ought to know of two basics of software testing:
Full testing is not possible.
Testing is always dependent on the environment.
The former states that the test of most possible inputs and configurations of an application cannot be performed due to the large number of possible combinations. With regards to the application, the user must always decide which functionality, which configurations and quality features must be prioritised and which are not relevant for him.
Which decision is manufactured, often depends on the next point ? the operating environment of the software. 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 selection of requirement perspectives and the sheer, endless complexity of the program configurations within the customer-specific application areas therefore ensure it is impossible for a manufacturer to test for all the 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 possible, a procedure fitting the following five points is preferred:
The info for typical calibration configurations should be defined as ?test sets?.
At regular intervals, typically once a year, but at 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, may take place.
Aggressive should 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, visit the WIKA website.