Developing Activity Construction Labor Productivity Model: A Case Study on Meles Zenawi Leadership Academy Construction Project
No Thumbnail Available
Date
2020
Authors
Journal Title
Journal ISSN
Volume Title
Publisher
Addis Ababa University
Abstract
Productivity is an influential variable showing the economics of production activities. Higher productivity levels imply increased profitability and the ability to pay higher wages to workers. In the Ethiopian building industry, construction labor productivity loss is one of the severe problems. Since labor is more flexible and volatile than other project-cost components, it’s necessary to understand the effects of the labor situation, which exist in the construction site and identify problem area that causes delay. To deal with this challenge, the study presents the methodology for the development of activity construction labor productivity models. To attain this objective, the subsequent procedures were followed: identifying seven process parameters that influence construction labor productivity, determine the observation method, determination of the minimum number of observations for study. The research conducted extensive field data collection from Meles Zenawi leadership academy construction projects in Addis Ababa covering a period of 4-months; and documented information using work sampling studies, foreman delay surveys, craftsman questionnaires, and productivity measurements. The validity of the data was tested to establish a 95 % confidence level. This helps to know errors that can be encounter during observation and hence, increase the reliability of data. A multivariable linear regression model for formwork, reinforcement, and concreting activities was developed to predict construction labor productivity. However, the models for concreting and reinforcement activity were limited to predict construction labor productivity. Travel, waiting and material handling for column formwork activities predict construction labor with a high degree of accuracy of 95.81% and R-square value of 98.5%. This indicates that the relationship between independent variables (travel, waiting, and material handling activity) and construction labor productivity of the developed models is good and the predicted construction labor productivity values fit with the real-life data. Overall significance tests and scatters plots were conducted to see the relationship between direct work and construction labor productivity. The result proves that direct work activity was not significantly correlated with construction labor productivity. Unavailability of material, poor site layout, crew failure to follow instructions, incomplete drawings, the low skill level of crew, waiting for other crews, and tools were the main causes of delay in the study area.
Description
Keywords
Productivity, Work Sampling, Regression