1. *EXPERT JUDGMENT  

Expertise should be considered from individuals or groups with specialized knowledge or training in the following topics:  

  • _ Schedule development, management, and control;  

  • _ Expertise in estimating; and  

  • _ Discipline or application knowledge.  

  1. *ANALOGOUS ESTIMATING  

Analogous estimating is a technique for estimating the duration or cost of an activity or a project

using historical data from a similar activity or project. Analogous estimating uses parameters from a previous,

similar project, such as duration, budget, size, as the basis for estimating the same parameter or measure for a future project.  

  1. *PARAMETRIC ESTIMATING  

Parametric estimating is an estimating technique in which an algorithm is used to

calculate cost or duration based on historical data and project parameters. 

  1. *THREE-POINT ESTIMATING  

The accuracy of single-point duration estimates may be improved by considering

estimation uncertainty and risk.

Using three-point estimates helps define an approximate range for an activity's duration:  

  • *Most likely (tM). 

  • This estimate is based on the duration of the activity, given the resources likely to be assigned,

  • their productivity, realistic expectations of availability for the activity, dependencies on other participants, and interruptions.  

  • *Optimistic (tO).

  •  The activity duration based on analysis of the best-case scenario for the activity.  

  • *Pessimistic (tP).

  •  The duration based on analysis of the worst-case scenario for the activity.  

Depending on the assumed distribution of values within the range of the three estimates,

the expected duration, tE, can be calculated.

One commonly used formula is triangular distribution: tE = (tO + tM + tP) / 3.

Triangular distribution is used when there is insufficient historical data or when using judgmental data.  

  1. *BOTTOM-UP ESTIMATING  

Bottom-up estimating is a method of estimating project duration or cost by aggregating the estimates of the lower-level components of the WBS.  

  1. *DATA ANALYSIS  

Data analysis techniques that can be used for this process include but are not limited to:  

  • *Alternatives analysis.

  •  Alternatives analysis is used to compare various levels of resource

  • capability or skills; scheduling compression techniques; and different tools.  

  • *Reserve analysis.

  •  Reserve analysis is used to determine the amount of contingency and

  • management reserve needed for the project. Duration estimates may include contingency reserves to account for schedule uncertainty.  

  1. *DECISION MAKING  

Decision-making techniques that can be used in this process include but are not limited to voting.

One variation of the voting method that is often used in agile-based projects is called the fist of five.

In this technique, the project manager asks the team to show their level of support for

a decision by holding up a closed fist (indicating no support) up to five fingers (indicating full support).  

  1. *MEETINGS  

The project team may hold meetings to estimate activity durations.