As an employer it is never in your best interest for you or your staff to harbor information in memory only. High level documentation holds a greater value to an organization because it gives you the ability to efficiently retrieve accurate information, consistently.

Time and time again I have stepped into an IT department and nothing is documented.  There’s always the one “guy” that has it all in his head, unfortunately that guy can never take a vacation and if he did and something did go wrong business could come to a screeching halt.

Make it standard practice to have a policies and procedures suite in place and keep it current.  Document everything, create your organization so that any employee could leave at a moments notice with little to no impact on business flow and productivity.