For organisations planning enterprise robotic process automation, what factors should be considered before scaling an RPA program?

I’m particularly interested in experiences around:

Identifying the right processes for automation
Integrating RPA bots with legacy and enterprise systems
Managing security and access controls
Handling exceptions and human intervention
Monitoring bots after deployment
Measuring ROI and operational improvements
Scaling automation across multiple departments

For those who have implemented RPA at an enterprise level, what challenges did you encounter, and what would you recommend organisations address before expanding their automation initiatives?