Design-construction interface performance on traditional capital improvement projects

Overall project performance is highly dependent on performance at the design-construction interface. Successful transition of the project from design conception into physical reality requires that design and construction teams effectively deal with such interface issues as: differing site conditions, constructability, operability, material shortages, systems' interference and design errors and omissions. Failure to deal effectively with these interface issues will result in change orders and cost and schedule overruns. This dissertation is one of the first research studies to examine the relationship between project performance and the design-construction interface. The design-construction interface issues and their effect upon change order performance are investigated with an inductive research methodology by using available project information. Requests for information (RFI) and change orders were collected from three projects similar in scope but with vastly differing performance evaluations. The RFIs are comparatively analyzed to determine the underlying design-construction interface issues. Trends in the relationships between project performance and the interface issues are examined for potential hypotheses. The RFI-related change orders are studied in depth to assess their ability to predict in advance total change order cost escalations and schedule delays. The relationships between the design-construction interface issues and project performance are investigated by statistical analysis of several cross-classification tables using the chi-squared test of independence. An indexing system for predicting final change order cost and schedule performance from analysis of the project RFIs is proposed, developed and demonstrated using the data from the three projects.