My personal experience is as follows and if you don't have any of those qualifications you employ a person to fill that requirement.
In order to succeed in business one requires Charm, Finesse, Looks, and Knowledge. They all go hand in hand . One is not enough must have ALL. Contacts are important but the first 4 will generate the contacts if one is willing.
You also must have a good market audience. Police force for example buys a lot of stuff ....so if you can get in as an approved supplier it could be a piece of cake. A friend of mine supplies helicopter engines as well as repairing them, and that is a lucrative market for him. They also buy a lot of consumables too. Consumable are regular business and always require replenishing.
In order to get approvals you must do a lot of things and obtain qualifications. That is not so easy. Police is not just the only market, security firms, even electrical engineering companies use a lot of consumables.