Yes, I think we're in agreement here. I agree that a startup is much harder than small business, for reasons you mentioned here, and others. I think you would agree that a small business is also hard, and success is far from guaranteed :).
Wait, the word startup is defined as a scalable subset of small business? I thought it is just a fashionable term for newly established small businesses...
Entrepreneurial ideas come and go. Some I don't give a second thought to. Others I commence market research for, examine the competitive landscape and explore the feasibility for development. This can be time consuming, and has yet to have produced any tangible, commercialized product.
I figure it's about time I devote the time I would spend to exploiting my existing repertoire of knowledge to develop an idea, to exploring parsimonious, efficient techniques for assessing viability.
In my search I found [Autopsy.io], a startup graveyard. Founders describe why their startups failed, concisely. It made me think about my past startup ideas and why they haven't flied.
I'm going to work that out, put it in a spreadsheet and regress to whatever problem keeps popping up - then, I'll work on improving my subject matter knowledge in that domain - for example, if its the feasibility of implementing with existing technology - I might learn more about the current technological landscape in general. Or, more about existing services for investors, if my product is a service for investors, like my last startup idea, which I have autopsied in detail here
I just thought I'd share my general strategy for anyone who'd want to copy this procedure for startup autopsy. Please use this space to suggest other appropriate diagnostic methods.