How To Use The PERT (Program Evaluation and Review Technique)?
Organizations use project estimation to plot its activities. Time estimate must accurate and must be achievable for a project to finish on the target date. This technique is used in management and information systems applications to construct an approximate probability distribution of tasks. The complexity of project estimation relies on how large the company is, and how many stakeholders it has to take care of.
PERT (Program Evaluation and Review Technique) is one the most widely used technique which can improve the estimation accuracy and reduces project risks.
The PERT Basics
PERT also involves breakdown of tasks by using simple statistical methods. These tasks are then distributed to the respective departments and people. This process is represented by using charts to show a graphical representation of the process. This process is chronologically arranged. Earliest time (TE) and the Latest time (TL) are also used to figure out the duration of each activity.
The Three Chances
PERT technique includes the following: Optimistic Time Estimate (TOPT), Most Likely Time Estimate (TLIKELY), and Pessimistic Time Estimate (TPESS).
- TOPT refers to the most ideal time as to when the tasks or activities are done. It could also mean that the available resources are maximized and used very well to complete the tasks on time.
- TLIKELY is when there are other estimates done by the management to resolve conflicts and bottlenecks.
- TPESS is the repetition of the whole process when the goal is not achieved. This estimate provides maximum time to get things done to be able to achieve the ultimate goal.
The PERT Mathematics
In the calculation of probability distribution of tasks using PERT, the Estimate and Variance are computed using. The total of V and E represents the whole time estimate for the completion of tasks and activities. Standard deviation is also used, to compute for the desired probability of tasks completion. A simplified, but less accurate method of computing the standard deviation is often used to compute for the project duration. This is when the optimistic value is subtracted from the PERT value divide by six.
Management Practitioners should use PERT method to standardize project estimates. It could yield to better results. PERT method shows the expected value for the duration of the project. This method can also be used in conjunction with the Critical Path. While PERT is best for individual tasks, CPM is more powerful method for estimating the time required to complete a set of tasks and activities. Thus, the combination of these two methods is strongly advised. PERT can accelerate the progress of a project or it can cause delays. The best idea of this method is to provide enough time to complete the tasks. The success of following this method is to send the deliverables on the expected date and in a very satisfying manner. The advantage of this method to cope with uncertainties and bottlenecks are the advantages of this project estimation method. This makes the time estimates more accurate than it may seem.