It's a sensitive subject but if you have a key member of staff that goes off sick or needs maternity cover it can be hard to get the right fit for that period of time, so as not to damage your business.

I think it's really important (especially in maternity cases) for the person going off from work not to feel pushed out or threatened. However, the business goals and objectives must be prioritised for maximum profitable return.

Observing the persons current workload and manner is vital to the continued success of the business and whoever comes in to cover whilst they are off will undoubtedly spot new opportunities. For this reason, maternity cover and sickness cover can actually be highly beneficial for the business itself. 
The goal for the person covering is to truly understand the mechanics of the business in its entirety and this can take time.
Having worked in global corporates and with SMEs it's likely I have already come across the challenges you are facing and therefore, can hit the ground running with no extra effort on your part.
It's an area often overlooked by sales and marketing consultants but something that businesses come up against continually.
If you would like to talk to someone about making the most of the resource you have, email me performance@gemmaangharad.com