> A product however, can be released "when it's done", so there is no real need to estimate. > The additional benefit is also that it can be released when the

> A product however, can be released "when it's done", so there is no real need to estimate. > The additional benefit is also that it can be released when the developers feel that the product is ready for release, > unlike a project, where there is a lot of pressure to deliver things. This view probably depends on your definition of "estimate", whether it's being done at an individual developers level or whether it's being done at a team/product level. For team/product level (as another commentator mentioned) if you don't have a cost/benefit analysis then you don't know if the work being done is worth doing, and you may run out of money before your product is "done". Additionally, (the article mentions this but it's worth expanding on) other bits of the organisation need to co-ordinate and depend on knowing status and when the product will be ready. To take an extreme example an enterprise software company might need to know with more than six months notice in order to start planning and preparing sales, marketing and PR teams for the coming release.