Processes will be changed over time. The wear and tear will change the properties of the process.
The functional model needs to be maintained and updated when the physical process is changed. However, there is no need for "tuning" of the model based on changing performance of equipment. But learnings from incident investigations and HAZOPs should be added/included in the model to continuously improve and learn.
The maintenance work of the functional models are not time consuming. However, continuous improvement as a result of incident investigations may result in physical changes in the plant and those modifications might require enhancement of the built functional model.
Note: Changes to Control system set-points and limits does not affect the model, but moving a signal physically will need to be re-mapped again in the OPC connection setup.
Maintenance and minor modifications will be updated by Kairos as a part of the SaaS license agreement. Whole new modules or adding new processes from the plant may require an upgrade activity.