Timing of Estimates

When to give estimates?

Estimation is vital to projects. At the start of a project, a plan is drafted for the project, including how many people will be on the team, based on a good estimate. Estimation is used to determine whether the customer’s intended deadlines are achievable. During a project, estimation is used to determine the impact of new and changed work items in order to monitor the growth of the scope and re-planning.

Estimation is, therefore, a continuous process in Agile and is employed in the following steps:

Start of the project

An initial estimate is needed to provide a quote for a project. In lightweight Agile approaches, this isn’t always described. This applies to Scrum or Extreme Programming. These projects start with the first iteration in which work items are already realized. Other Agile approaches, such as Smart, DSDM, and Feature Driven Development (FDD), contain initial iterations in which the work items for the backlog will be determined, an estimate will be completed and a quotation and project plan created.

During iterations

During iterations, the chosen work items are further detailed. User stories are split into tasks, Smart use cases are elaborated. With this new knowledge, an estimate is made to determine whether the amount of work fits into the iteration. The total estimate often also changes due to this, which has an effect on the expected duration.

Unfortunately, not all Agile projects establish an initial estimate, a quote, and a project plan.