My answer to How is it like to manage your own startup while working for a big company?
Answer by Ken Larson:
It generally occur es slower.
Insure you do not have any non-compete or non-disclosure agreements with the big company that would keep you out of the market.
Many of my clients take the route you have questioned for stability and gradually cut over after carefully developing a business plan consisting of market research, competitive analysis and revenue and cost forecasting.
It is possible to make test runs, phase in gradually and then phase out of the larger company as the startup matures, but it is a fairly lengthy process and the conflict of interest must be astutely managed.