Verifying the existence of a market Verifying the suitability of the work for you Acquiring know-how Finding financing for the uncertain early stages.
Franchises address the know-how issue and sometimes provide some access to financing.
But a solution to the entire problem has been successfully used for generations. There should be little doubt about its viability. Most important, it's financeable. Financeability is important. Banks have little interest in small startups unless most of the capital is already in place as equity and even then they are likely to require plenty of collateral.