At what levels do you conduct Succession Planning (ie Executive, Director level etc)? Do you conduct it for all roles or do you prioritize critical roles?

We prioritize succession planning for critical roles, focusing on senior managers, directors and senior management (VPs and up)

We must have succession plans in place for Executive level and Director level positions.

We then identify critical roles based on business continuity, market scarcity or occupant risk (etc) and ensure that there is a succession plan in place for those roles as well.

We have not started succession planning at my current organization just yet - but it's on my list. At my prior organization, which was much larger, we did managers and up to senior/executive management. 

We do succession plans for any Manager level role and for all critical roles. There are some critical roles that are individual contributor roles.