Causes of rework and its effects on project performance in turkish construction projects

In construction projects, significant problems such as higher costs than expected, poor financial planning and inability to deliver the work to the customer are encountered. These problems reduce the performance and efficiency of the construction projects. One of the most important factors causing this situation is rework. In the project process, errors, omissions and changes often occur, and this leads to rework at different stages of the project process. Studies in many countries have shown that rework increases the cost of different categories of work by between 3% and 30%, and causes delays in different work categories. It was concluded that the planned duration of these delays increased from 10% to 77%. In addition, rework cause dissatisfaction with customers and contractors. There are many research on rework reasons, rework classification systems, measures to reduce rework, and each researcher has carried out his research by introducing his own definition and approach. The definition used in this thesis is: "The unnecessary effort of re-doing a process or activity that was incorrectly implemented the first time." This definition covers both the design and the construction phase of the project process. For these reasons, this definition was accepted and research was conducted. Rework lead to extra cost and time delay in construction projects. Extra cost and time delay for project participants is a serious problem. The purpose of this thesis is to determine the causes of rework leading to cost and time delay in Turkish construction projects and the effect of these causes on project performance. As a result, measures were taken to improve the project performance. In the field research conducted within the scope of the thesis, face-to-face interviews were conducted with 33 experienced people in Turkish construction projects. In this interview, a questionnaire was applied in order to determine the frequency of reworks and its effects on the project performance. According to the survey findings, the most common and effective cause of rework in the design phase is: "Static, electrical, installation and architectural project lack of coordination". The interviewees said that there was no coordination between the projects in Turkish construction projects during the design phase. In order to reduce this, projects should be overlaid during the design phase and feasibility checks should be carried out before going into construction. The most common and effective cause of rework during construction is: "Pressure from time limitation". The interviewees stated that the construction phase started before the design phase ended due to the time limitation in Turkish construction projects. As the construction phase is started before the design phase is completed, project disputes, errors or deficiencies are encountered. This causes the project end with extra cost and time delay. Therefore, the interviewees suggest that the given time should be used more efficiently during the design phase and the construction phase should be completed after the design is finished. When we look at the external causes, the most common and effective cause of rework is: "economic factor". Economic fluctuations, especially the construction sector in Turkey is seriously affected. For this, business planning and budget planning should be made considering economic fluctuations. As a result, project planning and control, as well as qualified people who plan and control projects are important in both design and construction phases. Companies should allocate resources and time for business planning, budget and management planning and regular audits before construction begins. In order to reduce rework as common opinion of the interviewees, planning, programming and project management should be given great importance. Companies that do not allocate resources and time to reduce rework will continue to face time delay and extra costs. These companies will continue to suffer losses and lose their competitive power in the sector.