On average, what’s the lag between the start of production to being ready for sale in the store? I know it will vary, but for things like cell phones, books, furniture. What would be the average variations between those things?
Can be seconds for foods like fries and decades for foods like Scotch.
Well, Napier has nailed the answer but I think you already answered yourself almost as much. A product could go from a sketch to shelves in a week, or take five years of development, market study, refinement, holds for financing or production slots, etc. There are so many variables that an answer more precise than N’s is almost impossible.
From experience, I’d say that a consumer product that requires no particularly difficult development or preparation for manufacture will go from approval of concept to the first shelf distribution in six months to a year. That’s about how long the steps in the process take, including waiting times for early marketing to build a lead and so forth.