Chul Ki Chang

Monte Carlo Simulation Approach to Support Alliance Team Selection

The alliance concept is similar to the design build project delivery system. However, it is denoted by a special form of partnership between the owner and the design-build team, where the owner is very involved in the project. This type of delivery systems is gaining popularity as many infrastructure projects require the owner to order materials ahead of time, before engaging the design-build team in the project. As in design-build, the selection of the engineer-procure-construct team depends not only on the price but also on qualitative factors. This paper lays out the framework that facilitates selecting the best alliance team for a project by quantifying the evaluation factors and combining them into a single score. Using a Monte Carlo simulation and varying all the factors relevant to the decision problem can reveal biases present in the evaluation to assist in making the best possible decision. A case study dealing with a large utility project illustrates this methodology.

OVERMANNING IMPACT ON CONSTRUCTION LABOR PRODUCTIVITY

This paper details the impacts of overmanning on labor productivity for labor intensive trades , namely, mechanical and sheet metal contractors. Overmanning in this research is defined as an increase of the peak number of workers of the same trade over actual average manpower during project. The paper begins by reviewing the literature on the effects of overmanning on labor productivity. A survey was used to collect data from 54 mechanical and sheet metal projects located across the United States. Various statistical analysis techniques were performed to determine a quantitative relationship between overmanning and labor productivity, including the Stepwise Method, T-Test, P-Value Tests, Analysis of Variance, and Multiple Regression. The results indicate a 0% to 41% loss of productivity depending on the level of overmanning and the peak project manpower. Cross-validation was performed to validate the final model. Finally, a case study is provided to demonstrate the application of the model.

QUANTIFYING THE IMPACT OF SCHEDULE COMPRESSION ON CONSTRUCTION LABOR PRODUCTIVITY

In a typical construction project, a contractor may often find that the time normally e xpected to perform the work has been severely reduced. The reduction of time available to complete a project is commonly known throughout the construction industry as schedule compression. Schedule compression is a problem because it negatively impacts lab or productivity in various ways, and it becomes a source of dispute between the owners and contractors. This paper investigates how schedule compression affects construction labor productivity and provides a model that quantifies the impact of schedule com pression on labor productivity by analyzing 66 mechanical projects and 37 sheet metal projects collected from across the United States. The model can be used in a pro -active manner to reduce productivity losses by managing the factors affecting productivit y under the situation of schedule compression. Another useful application of the model is its use as a litigation avoidance tool after the completion of a project. KEYWORD

Shift Work Impact on Construction Labor Productivity

Schedule compression or acceleration is a common problem for specialty contractors. Schedule acceleration is often the result of late start, delays and/or added work. Generally, a contractor has three options in accelerating a construction schedule; scheduled overtime, increasing the number of workers, or creating an additional shift of workers. There has been a significant amount of research conducted on scheduled overtime on construction labor productivity. However, little information has been found in the literature addressing the cost implications or labor inefficiency associated with working a second shift. This paper quantifies the relationship between the length of shift work and labor efficiency. The results of the research show that shift work has the potential to be both beneficial and detrimental to the productivity of construction labor. The productivity loss obtained from the quantification model developed through this study range from –11% to 17% depending on the length of shift work used.