The primary causes of change orders are owner-initiated changes and designer’s errors and omissions (Issac
and Navon, 2008). The impact of changes to a construction project needs to be evaluated case by case in order
to assist with the decision making process. Though some changes may bring in “benefits” to the stakeholders
especially to the owner in the long run, most changes, if not managed properly, will result in “negative”
impacts, most likely resulting in time and cost overruns. In general, upper-stream changes have larger
impacts. Lu and Issa (2005) believe that most frequent and most costly changes are often related to design,
such as design changes and design errors.