Validation of calibration software ? as required by ISO 17025, for instance ? is a topic that people don?t prefer to talk about. Often there is uncertainty about the following: Which software actually must be validated? If so, who should take care of it? Which requirements should be satisfied by validation? How will you take action 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 is used, among other activities, from supporting the evaluation process, up to fully automated calibration. Whatever the amount of automation of the program, validation always identifies the entire processes into which the program is integrated. Behind validation, therefore, is the fundamental question of whether 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?
In order 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 a program cannot be performed as a result of large numbers of possible combinations. According to the application, the user must always decide which functionality, which configurations and quality features must be prioritised and that are not relevant for him.
Which decision is made, 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 regarding the contents of the certificate. But additionally 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 make it impossible for a manufacturer to check 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 process as efficient as possible, a procedure fitting the next five points is recommended:
The info for typical calibration configurations should be thought as ?test sets?.
At regular intervals, typically one per 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 previous version.
Regarding an initial validation, a cross-check, e.g. via MS Excel, may take place.
The validation evidence ought to be documented and archived.
Meltdown provides a PDF documentation of the calculations carried out in the software.
Note
For more info on our calibration software and calibration laboratories, visit the WIKA website.