Train the trainer
Train the Trainer is more in depth training, focussed on developing a new instructor to the point where they are able to deliver a new course effectively.
In these sessions, they are taught to present information effectively, respond to participant questions and lead activities that reinforce learning.
Typically, a new instructor observes an experienced instructor and participates in the training, before practising the delivery of a portion of the training themselves.
Through this kind of training a community of trainers may be developed. This takes the emphasis away from having a single subject matter expert and lessens the risk to the business.