RDL already pointed out that shipyards (and other large manufacturing sites) do operate this way. There is one problem with a y-combinator approach to capital

RDL already pointed out that shipyards (and other large manufacturing sites) do operate this way. There is one problem with a y-combinator approach to capital intensive work: someone has to be in charge. There is 'a' party responsible for delivering the product to the customer, and that drives everything else. Put ycombinator in charge of a shipyard and a lot of cool stuff will happen, but delivering a finished boat on time and on-cost is not one of them.