Agile Software Development

Agile software development methods are sometimes criticized for the inability to rely on. Agile project managers are unable to produce the fixed upfront effort-time-costs estimation. Sometimes it is even the core argument of the waterfall process proponents.

In fact agile manifesto principles "Customer collaboration over contract negotiation" and "Responding to change over following a plan" do not state that contracts and plans are useless. Agile community recognizes the value of contracts and plans, it is just so, that the agile developers value collaboration and responding to change more. If there is a possibility to create the upfront time and costs estimation, the agile team would be glad to do it. Unfortunately, in most of cases it is hardly possible. However, the agile approaches provide an alternative to the heavy upfront requirement analysis and design - iterative approach to estimations. Every next iteration, plans can and should be reevaluated, and estimations - readjusted.

The first two-three iterations after which the estimations become rather reliable often take less time than the traditional requirements analysis phase. Estimations can become even more reliable if during these first iterations, the team worked on the items with the least understanding exactly to produce the better estimations.

Did you yourself notice that the agile teams come to the reliable estimations faster, than their waterfall counterparts? If you worked in an agile team, that had to make hard contracts, did you manage to delay the contract details until couple of first iterations was completed?