Time and cost overruns are an integral part of the construction projects. Both have several associated negative consequences to the project owners. Setting the right time and cost contingency is a major contributing factor to the success of the project as it should minimize/prevent budget and time overruns. Project managers usually tend to allocate project time and cost contingency subjectively based on their previous experience and may not capture all projects specific factors that impact the contingency estimation. The competency of the project manager plays an important role in this case in determining the contingency percentage. The contingency estimation for a given project can hugely vary from one project manager to another. This research presents a fuzzy logic-based model that allows owners predict the project time and cost contingency reliably and accurately in Egypt. The most important factors affecting time and cost contingency have been identified and are defined as input variables for the model. The effect of these factors on the time and cost contingency, the output variables, have been determined and incorporated into the model via fuzzy rules. On the basis of the known effects of these factors, a fuzzy logic model is developed to automate the prediction process using MS Excel software. Several scenarios of the model are developed and subjected to initial testing using 10 actual projects data. Based on the initial testing, the best model was subjected to tuning in order to achieve the optimum model results in terms of accuracy and validity. Finally, the model is tested by applying it on new five actual construction projects which were not used in the initial testing nor tuning. The model results were found to be acceptable having an average validity percent of 84% and 81% for time and cost contingency, respectively. The proposed model allows the owners to [1] understand the effect of the project different factors on the contingency values, which in turn represent the degree of risk involved and accordingly, allows the owner to take necessary measures at the preconstruction stage to reduce the risks, [2] minimize the cost and time overrun through setting the right amount of contingency, [3] avoid tie up of excessive funds for the project, which can be used in others projects or activities, and [4] have higher confidence during the decision making process of whether to proceed or not to proceed with the project.


Construction Engineering Department

Degree Name

MS in Construction Engineering

Graduation Date


Submission Date

May 2017

First Advisor

Hosny, Ossama

Committee Member 1

Marzouk, Mohamed

Committee Member 2

Ezeldin, Ahmed


115 p.

Document Type

Master's Thesis


The author retains all rights with regard to copyright. The author certifies that written permission from the owner(s) of third-party copyrighted matter included in the thesis, dissertation, paper, or record of study has been obtained. The author further certifies that IRB approval has been obtained for this thesis, or that IRB approval is not necessary for this thesis. Insofar as this thesis, dissertation, paper, or record of study is an educational record as defined in the Family Educational Rights and Privacy Act (FERPA) (20 USC 1232g), the author has granted consent to disclosure of it to anyone who requests a copy.

Institutional Review Board (IRB) Approval

Not necessary for this item


In this section, I would like to seize the opportunity to make acknowledgment to all who have supported and mentored me to achieve my current academic and professional standing. I would like to start by expressing sincere gratitude and appreciation to my thesis advisors, Dr. Ossama Hosny and Dr. Khaled Nassar, for their efforts, continuous support, guidance and mentorship throughout my research. They truly served as great mentors, and always availed the time to follow up on my work and offer advice. Not to mention, they served as the instructors of many courses I have attended during my academic journey at AUC.