In the article “Why You Should Not Estimate in Hours or Days“, author Stephen Walther discusses the apparent conflict between developers that don’t like to provide estimates and managemers that need project management estimates because they want to know how many resources they need to allocate to a project and have a schedule for delivery.
His opinion is that it is extremely difficult to estimate how long it will take to implement a software feature, because “writing software is more like Finding a Cure to Cancer than Building a Brick Wall”. The article explains how the Scrum Agile Project Management framework provides a solution to this problem. In Scrum, you define features as User Stories and you do not attempt to estimate them using hours or days. Instead, you use story points. User stories are divided into tasks before they will be realized during Scrum sprint and this makes more sense.