Formulation & Optimization of Standard Labor Productivity for Building Works in Pakistan

Abstract

Knowledge of labor productivity is essential for cost estimation and progress control. The accurate prediction of productivity is essential to effectively plan operations that depend on time and cost and is critical for the success of a construction project for both the contractor and the client. Lots of efforts have been made as of today to identify the factors effecting the productivity of construction works. One notable gap in existing literature pertains to the lack of focus on optimizing productivity for each trade involved in building construction within Pakistan. This research emphasizes on formulation and composition of standard construction party for each task being carried out in building construction through a Structured survey utilizing expert opinion, with a 56% response rate. PERT analysis is used to determine the Expected productivity of 38 identical activities with Anti termite treatment and Door’s casting and fixing being the most and least productive respectively, concerning time. Monte Carlo simulation using @Risk Software is utilized to optimize the Expected productivity taking into consideration different factors affecting labor productivity including error, change in scope of work, timely availability of resources, delayed payments, geographical location and weather. The average percentage increase in Expected productivity to probabilistic productivity in normal weather conditions translates to a figure of 81%, taking into account the factors considered. Similarly, Hot weather, Very Hot Weather, Cold Weather, and Very Cold Weather correspond to an increase of 101%, 104%, 104%, and 106%, respectively. Probabilistic productivity obtained from the iterations was implemented to determine the overall duration of two case study projects (MES & HEC) utilizing Oracle Primavera P6 scheduling software. The actual duration of projects was also recorded for comparison with the scheduled duration derived from Monte Carlo analysis. After applying the productivity rate determined in this study on case study projects, the duration of the projects was accurately assessed duly matched with the actual and contractual duration estimates. This leads to the validation of the results of this study. Standardization of the composition of parties and determination of the probabilistic productivities will reduce the chances of over employment on any project which will ultimately control the budget of the project in particular and economy of country in general. Since the subject study only focused on the construction field in buildings thus there is a need to extend this study on other fields like Road and structure works.