Topdownarviointi

Topdownarviointi, also known as top-down estimation, is a project management technique where a project's total cost or duration is estimated by breaking it down into major components or phases. This approach begins with an overall estimate for the entire project and then allocates portions of that estimate to the high-level tasks or deliverables. The initial estimate is typically provided by senior management or experienced individuals who have a broad understanding of the project's scope and objectives.

This method is often employed in the early stages of a project when detailed information about individual tasks is not yet available. Its primary advantage lies in its speed and simplicity, allowing for quick, albeit less precise, estimates. Topdownarviointi is useful for setting initial budgets, feasibility studies, and for making high-level strategic decisions. However, its accuracy can be limited due to the lack of granular detail. As the project progresses and more information becomes available, a bottom-up estimation approach is often used to refine and validate the initial top-down figures. The difference between top-down and bottom-up estimation highlights the trade-off between estimation speed and accuracy in project management.