Validation of calibration software ? as required by ISO 17025, for instance ? is a topic that folks don?t like to talk about. Almost always there is uncertainty about the following: Which software actually must be validated? If that’s the case, who should look after it? Which requirements should be satisfied by validation? How does Humor do it efficiently and how could it be documented? The following blog 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. Regardless of the amount of automation of the program, validation always refers to the complete processes into which the program is integrated. Behind validation, therefore, is the fundamental question of if 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?
In order to do validation tests now, you ought to know of two basic principles of software testing:
Full testing isn’t possible.
Testing is always dependent on the environment.
The former states that the test of all possible inputs and configurations of a program cannot be performed due to large number of possible combinations. With respect 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 manufactured, often depends on the second point ? the operating environment of the software. Depending on the application, practically, you can find always different requirements and priorities of software use. Additionally, there are 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 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 an individual themself. To make this process as efficient as you possibly can, a procedure fitting the next five points is preferred:
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 should be entered in to the software.
The resulting certificates could be compared with those from the prior version.
Regarding a first validation, a cross-check, e.g. via MS Excel, may take place.
The validation evidence should be documented and archived.
WIKA provides a PDF documentation of the calculations completed in the software.
Note
For more info on our calibration software and calibration laboratories, visit the WIKA website.