American Society of Civil Engineers


Impact of Change Orders on Labor Efficiency for Electrical Construction


by Awad S. Hanna, M.ASCE, (Assoc. Prof., Dept. of Civ. and Envir. Engrg., Univ. of Wisconsin–Madison, 2260 Engrg. Hall, 1415 Engineering Dr., Madison, WI 53706), Jeffrey S. Russell, M.ASCE, (Asoc. Prof., Dept. of Civ. and Envir. Engrg., Univ. of Wisconsin–Madison, 2304 Engrg. Hall, 1415 Engineering Dr., Madison, WI), Erik V. Nordheim, (Prof., Dept. of Statistics, Univ. of Wisconsin–Madison, 120 Russell Lab., 1630 Linden Dr., Madison, WI), and Matthew J. Bruggink, A.M.ASCE, (Proj. Engr., C. G. Schmidt, 4199 N. Richards St., Milwaukee, WI 53211-0609)

Journal of Construction Engineering and Management, Vol. 125, No. 4, July/August 1999, pp. 224-232, (doi:  http://dx.doi.org/10.1061/(ASCE)0733-9364(1999)125:4(224))

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Document type: Journal Paper
Discussion: by John J. Farbarik, P.E. E-mail: farbarik@pacific.telebyte.com    (See full record)
Closure:(See full record)
Abstract: Change orders are a source of many disputes in today’s construction industry. The issue at hand is whether or not the execution of change orders work has a negative impact on overall labor efficiency on a construction project. Previous literature demonstrates evidence that change orders affect labor efficiency. Attempts have been made to quantify these impacts by many researchers, with limited success. Using the electrical construction industry, a research study has been conducted to quantify the impacts of change orders on labor efficiency. In this paper, results of hypothesis testing and regression analysis are presented. A linear regression model that estimates the loss of efficiency, based on a number of independent variables, is also presented. The independent variables used in this model are (1) qualitative and quantitative criteria used to determine whether projects are impacted by changes or not; (2) the estimate of change order hours for the project as a percentage of the original estimate of work hours; (3) the estimate of change order hours for the project; and (4) the total number of years that the project manager had worked in the construction industry. Additional projects were used to validate the model, with an average error rate of 5%. The results of this research study are useful for owners, construction managers, general contractors, and electrical specialty contractors, because they provide a means to estimate the impact of a change order under certain project conditions. This research also identifies factors, which, when understood and effectively managed, may be used to mitigate the impact of a change order on project costs and efficiency.


ASCE Subject Headings:
Change orders
Construction management
Electrical systems
Efficiency
Labor
Productivity
Regression models