Whether you realise it or not your business already has a quality management system.
You have a way of doing things, it may not always be consistent and your way of doing things may, or may not be documented. Maybe you just “get by”. Maybe you rely on experienced staff who just know what to do. Maybe you are a start-up and decisions and processes are made “on the fly”.
If you were to lose an experienced member of staff would you still output a product/service that was of the same quality? If you won a large contract and suddenly needed to hire people, would you have the process infrastructure in place to ensure your product/service was of consistent quality?
The real question is: Is your current quality management system robust?