The BEST processes to automate are those that are:

Being performed by Service Operations is not a criterion for automation suitability; a Service Operations process can still be complex, poorly documented, or exception-heavy, making it a poor automation candidate.

The number of people performing a process indicates scale but not simplicity or clarity; a process carried out by many people may still be inconsistent or poorly understood, increasing automation risk.

Criticality to the business mission increases the cost of failure, so automating critical but complex or poorly understood processes without first simplifying and documenting them introduces significant operational risk.

ITIL guidance states that automation should target processes that are already clearly defined, stable, and well understood, since automating a poorly understood process risks codifying defects and making them harder to detect. Simple, well-documented processes yield the highest reliability gains from automation and carry the lowest implementation risk.