Now there is a SCADA system that I need to validate. In addition to system permissions, alarms, audit trails, print functions, for data accuracy how do I do? Do I need to check the consistency of data between SCADA data and equipment? Does every data need to be checked?
Thank you very much
Loops checks should be done as part of SCADA set-up. Then calibration might also be done (for critical attributes). The calibration will check the scaling and consistency of the data. For non-calibrated probes, and verification should be done for each point.
Incorrect scaling is a common error in SCADA set-up. Scaling is similar to a correction factor, or a conversion between a signal and a read-out.
It is acceptable and more efficient to test scaling and probe readout during commissioning (not qualification) since correcting an error during commissioning is much easier and often without QA oversight - since commissioning is often an engineering/start-up activity.
I think SCADA is having two different core parts in system
- Measuring part
- Controlling Part , Both of the parts are important for correct data transmission. Measuring part important for its accuracy and consistency and controlling part is important for correct data receiving, display, recording, print and archiving. Additionally control part operate through external command. So access controls and security also validated for control part.
Both parts must cover during validation. Measuring part can be validated based on its functional requirement and controlling part should be validated according to computer system validation.
How to validate the Measuring part ?Do I need to check the consistency of all data between SCADA system and equipment?And What is the acceptance criteria?
when I test scaling and probe readout during commissioning, What is the acceptance criteria?Do all the data have to be consistent?
Yes all data must be consistent. Error in the result should not differ more 1 % or 1’C from actual value. The acceptance criteria is depend upon criticality of usase or operational requirement.
Start with a Risk Asessment to identify the critical functions. The acceptance criteria for data consistency need to be set risk based, too. Clearify, right from the start for which compliance rules you are aiming for.
Important general points might be:
Alarm management, Access Management (critical parameters should not be available to everyone; peronalized access in order to ensure training for users), data transfer (input), data transfer (output); backup and recovery (both: Controling part and measuring part (data!)); define the data life cycle for measurement data (electronic data/print out paper data?); Responsibilities (System/Process Owner); instructions/SOPs for user and admin (if applicable).