When talking about succession planning, there's a tendency to focus on the highest levels within your company. But it's likely that people outside your organization play critical roles for your business, as well, and it's important to have a plan in place for them.

Mayer Electric, for example, launched discussions with its critical vendors, such as its accounting firm and family business consultants. The $741-million family-owned business wanted to make sure those critical roles filled by outside resources would continue even if something were to happen to the primary contact.

“One day I was meeting with the group, and (Mayer's owner Charles Collat) came in,” recalls Craig Aronoff, co-founder and principal consultant for The Family Business Consulting Group Inc. “He took me aside and said: ‘Look we’re talking about succession for everyone – for the chairman, for the board, for the executive positions. We’re talking about succession for everyone – except you. Who’s going to be your successor?’”

It's inevitable that the people you work with will eventually be unavailable to work with you – whether it's planned or not. But you can prevent disruption in their services by planning for these eventualities. Ask your current advisers, consultants or other third-party affiliates if there is someone else in their organization you can work with, as well, so that when that time comes, they're already familiar with your company and you've already built a working relationship.

Read more about Mayer's succession strategy in the MDM case study Mayer Electric: Protecting the 'Goose that Laid the Golden Egg'.