Design-construction interface problems in construction projects

Abstract

There is ongoing inefficiency and traditionalism in the construction industry. Throughout the development of Industry in general, the construction industry received the least positive impact. Many different management systems can be applied and developed in the construction industry like agile transformation, lean management etc. Yet the construction industry has not fully implemented any of the developments. However, it is seen that there is a lack of information on lessons learned from past experiences and mistakes. For this reason, budget, time and quality deficits have started to be given due to the increasing incompatibility of the inefficiency from the way of doing business with today's complex projects and resources. Throughout the lifecycle of the construction projects, the common aim for all participants is to achieve a "perfect" project with less cost at a minimum schedule. The biggest difficulty experienced while advancing the project process is to exhibit the right approach to the problems that arise. A real challenge emerges when deciding how to define and mitigate the causes of design-construction interface problems in the process and reduce the negative impact that is or will be reflected on the project. The thesis research aims to identify the causes of design-construction interface problems and to determine their frequency of occurrence and degree of importance. At this point, while analyzing the frequency and importance of these problems from the eyes of industry professionals; it is also important to reveal whether there is any difference in the perspectives of different professionals. In this context, to achieve the mentioned aim, the thesis research is developed in two main parts. The first part includes a comprehensive literature review to find out what are these design- construction interface problems, how they occur and how they impact the construction project life cycle. Databases are searched for in the areas where the problems are thought to originate. These main areas are stakeholders and their relationships and management, construction project phases and situations occurring at the interface of these phases, design phase and design management. At the intersection of all these areas, the problems that occur during the construction project process are listed and grouped according to the project phases in which they occur. In the second stage, a questionnaire survey is conducted with the design-construction interface problems gathered from the literature to measure the frequency of occurrence and degree of importance of these problems. The first part of the questionnaire gets general information about the respondents, the second and the third parts search for the frequency of occurrence and degree of importance of design-construction interface problems on a 5-point Likert scale, the last part has an open-ended question that aimed to get the opinions of the survey participants on the subject. The data that is obtained with the help of the questionnaire is analyzed through the SPSS program. In the first step, Cronbach's alpha reliability test is used to ensure the reliability of data. Secondly, frequency and descriptive analysis are used to get the frequency of each response. Third, the rankings of all variables are calculated using the Relative Importance Index (RII). Fourth, Skewness-Kurtosis values are evaluated to determine whether the data were normally distributed. Survey participants were divided into groups (designer, consultant and contractor); one-way ANOVA tests were applied to investigate whether there was a statistically significant difference between the groups. Finally, the variables were analyzed in one-way ANOVA test to determine if there is a statistically significant difference between stakeholders. According to the results of ANOVA tests, further post-hoc analyses were applied to the variables to show from which groups the differences came from. As a result, "PDC16 - Economic Situation" and "PC9 - Construction errors and defective work at the construction site" become the most occurred and most important problems from the consultants' point of view. "PD8 - Lack of proper coordination between various disciplines of the design team" cause is ranked as the most occurred and most important problem from the contractors' point of view. And, "PT5 - Awarding the contract to the lower bidder price regardless of the quality of service" is found as the most occurred and most important problem for the designers. "PT5 - Awarding the contract to the lower bidder price regardless of the quality of service" is ranked at the top both in the lists of designers', consultants' and contractors' . "PDC17 - Fast Track Construction" becomes critical for consultants and contractors; "PD6 - Time limitation in the design phase" and "PD9 - Unstable owner requirements" are important for contractors and designers. This thesis research identified the causes of design-construction interface problems seen in construction projects according to the project stages; and determined the frequency of occurrence and degree of importance of these problems from the perspective of different construction project professionals. To be aware of problems to detect them when necessary and to raise awareness to take the necessary action when encountered; supported by recommendations. Thus, it has been seen that, although the results vary for each stakeholder, it has been determined that there are similar points. The findings of this thesis research can help construction project professionals by providing an understanding of the design-construction interface primary problems. By having knowledge of the main problems and their impacts, participants can take precautions, make effort to minimize their impacts, and after all make a significant contribution to the successful completion of construction projects.