Work changes are alterations to the original scope of a contract. Work changes are inevitable in a typical construction project due to the complex nature of the construction industry. It is not possible to foresee these changes at the pre-construction or bidding stages. The changes may affect originally planned means and methods and, thus, may impact the quantity and type of the originally allocated resources such as time, labor, and equipment. In other words, work changes may involve time, money or both. Proper quantification of the impacts solely introduced by changes is therefore vital to all parties and to the success of a project. Failing to quantify impacts due to changes may have adverse consequences that may sometimes result in litigation.

Several techniques are currently employed by the construction industry to quantify the impacts of changes. There are also a few simulation case studies used for productivity-related impact analysis. Certain simulation techniques and capabilities, such as modeling flexibility, involvement of historical data, and capability to compare alternatives enable simulation to be a promising tool for quantifying impacts due to changes. Despite the fact that simulation is becoming popular in the construction industry, up to this point in time, there are no established guidelines for the use of simulation in quantifying impacts due to work changes. Simulation still needs exploration with further research and applications that are specific to the problems of the construction industry. There is a solid need to explore the opportunities for employing simulation in quantifying impacts.

The objective of this work is to explore the use of simulation in quantifying work change impacts. The study consists of a literature review on the relevant topics. It also analyzes and quantifies a case study in depth. The lessons learned from the case study showcase the procedure and potential of the methodology. The output of the research is valuable for practitioners who wish to employ simulation in quantifying impacts due to work changes.