Three point estimation: It is created by using previous experience. It is also called program evaluation and review technique. It increased accuracy over one point system. It is also called three set assumption. The first set is optimistic estimate, second set is pessimistic estimate and third set is in between two.
b) Triangular Estimation: It is like average of the three estimates. It includes time and that would be considering the complexities such as three estimate times would be equal.
c) Analog Estimation: It is one of the most common techniques of estimating. This process takes past experience and implements in the current project.
II. It is highly impossible for the project manager to decide which estimate is better among three. For different level of projects we should use different techniques. It is decided based on the size, resources, cost and risk of the project. By seeing the pros and cons of the project we will decide the type of estimate we need to consider. If the project manager commits small mistake in making decision, this may impact his carrier in the organization. The project manager should select a good estimating technique among three estimations.
III. If I am the project manager, I will decide any one model based on the need and size, available resources, and cost. Based on my prior experience I will determine the project. Client should trust project managers in the way handling business and taking decisions.