The construction industry is very risky compared to other industries, it is widely varying, also several factors will impact on the projects outcomes. As construction projects become larger and more complex, their management and challenges become more complicated. According to Central Bureau of Statistics, the estimated contribution of the construction sector operating about 10% of the total local workers in Palestinian areas in 2005, and estimated contribution of unregulated construction sector of the total value added in 2003, about 72%, the work in this sector provides good income for a wide range of members of Palestinian society. During the past few years, many of the construction projects in West Bank completed beyond planned timeline and planned budget cost .
Construction industry passes through several stages, where a lot of obstacles have been identified in these stages. The largest problem that facing most industrial sectors and especially the construction sector, is the Israeli occupation by the attacks on the various regions through imposing high taxes on an imported materials, and even manufactured. Which in turn lead to problems in the construction and problems in allocated time for the implementation of construction projects. The delay in the completion of construction projects is the most important factor that will lead to projects failure. Usually the determination of project duration is not made in a logical manner; therefore this research will identify how the project duration determined in Palestine and what is the problem encountered that obstacle determining logical duration for the projects.