Agony of calibration software ? as required by ISO 17025, for example ? is a topic that people don?t prefer to talk about. Almost always there is uncertainty about the following: Which software actually should 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 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 program, validation always refers to the complete processes into which the program is integrated. Behind validation, therefore, may be the fundamental question of if the procedure for calibration fulfills its purpose and whether it achieves all its intended goals, in other words, does it supply the required functionality with sufficient accuracy?
If you want to do validation tests now, you ought to know of two basic principles of software testing:
Full testing is not possible.
Testing is always influenced by the environment.
The former states that the test of most possible inputs and configurations of an application cannot be performed because of the large numbers of possible combinations. According to the application, the user should always decide which functionality, which configurations and quality features should be prioritised and that are not relevant for him.
Which decision is manufactured, often depends on the next point ? the operating environment of the software. Depending on application, practically, you can find always different requirements and priorities of software use. There are also customer-specific adjustments to the software, such as concerning the contents of the certificate. But also the average person 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 ensure it is impossible for a manufacturer to test for all the needs of a particular customer.
Correspondingly, considering the aforementioned points, the validation falls onto an individual themself. In order to make this technique as efficient as possible, a procedure fitting the next five points is preferred:
The data for typical calibration configurations should be thought 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, may take place.
The validation evidence ought to 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.