Estimating the normal duration using normal Production Rate per Day (PRPD) of project activity

摘要

A Project Estimator cannot claim that his/her estimated duration is better than others. They can determine the reasonable duration based on deterministic and probabilistic factors affecting the duration and then specify how to achieve it. This condition provides an overview that the activity duration changeable stochastically as a result of uncertainty-factors. However, we have a presumption that the activities duration will be normally distributed based on variation of its production rate per day (PRPD). The purpose of this study are (i) estimating the normal duration of the project activities using PRPD; and (ii) conducting the hypothesis testing for the PRPD normality of the project activities in South of Aceh. Hypothesis testing toward six-activities from 50 projects in South of Aceh will be used to achieve research objectives. Result shows PRPD normally distributed with skewness value still falling inside tolerance range of -1/+1. We argue that the normal duration of activity can be estimated more quickly involving its normal PRPD. An estimator does not need to predict what the factors affecting the duration estimation, especially in the bidding/tender process. They only need the normal PRPD as a standard value, to estimate, to assess and to verify the normality level of actual duration for the purpose of project decision.