Inflation factors in labor and equipment cost were incorporated in the sensitivity analysis based on assumed costsвЂ™ fluctuation range. After that, sensitivity analysis on the mentioned parameters was conducted to further explore the modelвЂ™s sensitivities to these parameters. Not only, the total labor and total equipment cost of a project is available, labor and equipment cost of each activityвЂ™s option can be calculated and compared with other options. Here, more than that we had earlier, we can analyze different options based on just one of these factors to find the optimum solution.

Presented results show each of labor and equipmentвЂ™s portion in total cost. Case results are presented based on deterministic values of Cobb-Douglas functionвЂ™s parameters (and ). A case study was presented to show how the proposed framework works. This new perspective fills a gap of existing time-cost tradeoff research by considering project duration, labor and equipment cost as parameters of the Cobb-Douglas production function.

Cobb-Douglas production function, which defines the portion of labor and equipment needed based on the production rate, provides a much-needed piece to modeling the cost functions in the construction time-cost tradeoff problem during the schedule crashing process. In the existing literature crashing cost function was either assumed without much justification, or came from ad-hoc regression analysis of historical data of some actual projects. Existing research on construction time-cost tradeoff issues rarely explore the origin of the crashing cost which is defined as the cost needed to shorten the project to the desired duration. In this thesis we explored this functionвЂ™s application in construction schedule crashing and project risk analysis related to duration of construction projects. The functionвЂ™s quantitative modeling of resource inputs and production outputs is appealing to the research domain of construction management. Cobb-Douglas Production Function was widely used in economics and productivity studies across many sectors.

Cobb douglas production function