Definitive EstimateĪll project estimates involve assumptions, constraints, uncertainty and risk. Evolving Estimates and the Concept of Progressive Elaboration Rough Order of Magnitude vs. It is important to establish the range of uncertainty for various parameters. Throughput is the number of items that can complete a process in a given amount of time.Īdjusting estimates for uncertainty: Estimates are inherently uncertain and therefore associated with risk.

Cycle time is the total elapsed time it takes one unit to get through a process. The estimates are developed by determining the cycle time and throughput.

Relative estimates only have meaning within a given context.įlow-based estimating: Flow-based estimating provide an estimate to complete a specific quantity of work. Relative estimates are shown in comparison to other estimates. Probabilistic estimating include a range of estimates along with associated probabilities within the range.Ībsolute and relative estimating: Absolute estimates are specific information and use actual numbers – eg. There are different ways of presenting and adjusting estimates given a particular context as follows:ĭeterministic and Probabilistic estimating: Deterministic estimates are also known as point estimates and it presents a single number or amount such as 24 months. Project Estimating Process apply estimating techniques to deliver project estimates with known level of accuracy.

Bottom up estimating