Keyman insurance is simply life insurance on the key person in a business. Usually the owners, founders or a key employee. These are people who are crucial to a business. The purpose of key person insurance is to help the company survive the blow of losing the person who makes the business work.
On top of keyman insurance you can also consider to have a golden hand shake with your employees to fund for their retirement/ employee benefits and retain them for a certain number of years as determined by the company.