Startups typically begin by a founder or co-founders who have a way to solve a problem. The founder of a startup will begin market validation by problem interview, solution interview, and building a minimum viable product (MVP), i.e. a prototype, to develop and validate their business models. The startup process can take a long period of time, and hence sustaining effort is required. Sustaining effort over the long term is especially challenging, because of the high failure rates and uncertain outcomes.