Dynamic System to Manage Variation Orders in Iraqi Construction Projects

Abstract

ABSTRACT Construction projects in Iraq suffer from problems of delay and the increase of the actual cost over the estimated cost, which is largely due to the problematic nature of the construction industry; for example, lack of integration of the design and construction processes of projects most especially through traditional method often leads to variation orders. Therefore, the traditional methods of managing variation orders can no longer succeed, continue, and withstand the change in the contemporary construction environment in light of a complex and continuous dynamic environment. Accordingly, the contemporary construction industry has become more need to be managed in dynamic ways in order to be able to continue and achieve the required goals. The Dynamic System to manage the variation orders to achieve the project goals is a way that brings life to the construction project by simulating the effect of variation orders for cost and time in order to create successful work and can adapt to the variations that occur obstruction to the completion of the project within the specified period and budget It is representing through a collection of the independent variables, and they stably interact with each other; the links between the underlying and variables' relationships into a system are called the system's structure This research aims to identify the causes of variation orders and take proactive measures to reduce variation orders in the project, diagnose VIII problems resulting from variation orders, and how the dynamic System can be employed in building a system to simulate the effect of variation orders on the cost and time. To achieve the research aims, the collected data from the previous studies and literature in this field have been reviewed, dealing with the variation orders and the Dynamic System. Also, the data from the field survey for twenty seven projects were collected properly from the University of Diyala through the years (2008-2020) for the purpose of this study. In addition, data were collected from a questionnaire and interviewing a group of engineers and academics who are in contact with the variation orders in the construction projects; the results of the present study are 43 causes and ten impacts in the construction projects, where the highest causes late a contractor in execution and the highest impact was a delay in project scheduling completion, and the results indicated that the largest ratio of the average percentage of variation occurs between (10%-30%) of the project's total cost However, based on the field survey and questionnaire results, two Dynamic System models have been developed. The first model measures the impact of variation orders on cost and time. In order to ensure the application of the proposed model, an evaluation questionnaire was conducted on a sample of engineers which confirmed the applicability of the model and the results in the simulation, the total weighted average time, and the actual weighted average time in years (2014-2015) at a percentage of (7% and 8%) for an actual weighted average time increased more than the total weighted average time at a percentage of (0%). Finally, in this research, several conclusions have been reached, including that many variation orders accrue in the Iraqi construction projects, a lack of managing variation orders in the projects, the impact of contractor and owner, and the legislative alteration and insurgency in the construction projects