The effect of selected request for information variables on steel fabrication outcomes

The fabrication of the structural steel is a critical process in the supply chain of many construction projects. The steel fabrication process depends upon documentation that is often in need of clarification due to issues involving completeness and coordination. Clarification is obtained by the steel fabricator through the request of information (RFI) process which allows the shop drawing production process to continue forward. The volume of requests for information (RFIs) sought, as well as time required to receive clarification, are just two of many variables that may result in substantial delays in the performance of shop drawing production. Since the production and approval of these shop drawings is a precursor to the actual fabrication of steel elements, performance in this stage may influence subsequent cost and duration performance outcomes. The goal of this research is to provide quantitative information on the relationship between selected RFI variables and the performance of the shop drawing production process as well to determine any significant associations between performance in shop drawing production and subsequent cost and duration performance in the fabrication stage. This research also provides quantitative information regarding recommended RFI characteristics and performance measures. Regression techniques were conducted to identify individual RFI variables having a significant influence on models to predict shop drawing production performance. A one-way ANOVA technique was performed to determine the effect of RFI transmission methods on shop drawing production performance, while two-way ANOVA techniques as well as the association between shop drawing production performance and the subsequent fabrication cost and duration outcomes. Finally, independent samples t-tests were performed to determine significant differences in shop drawing production, fabrication cost, and fabrication duration performance based on the use of individual data items within RFIs. The results of this research indicate that several of the selected RFI variables are significant predictors of the performance of shop drawing production. The RFI performance indicator, the average RFI response time, and the percentage of RFI follow-up all were found to the significant independent variables. Robust regression models were developed using one or two of these variables to predict shop drawing production performance. Additionally, two-way ANOVA techniques revealed a significant relationship between performance of shop drawing production and the performance of fabrication duration. This association between the duration of the shop drawing production and fabrication phases may be the focus of future research that seeks to identify threshold values of such variables that transition a project from good to poor performance. Tracking of these variables may also assist organizations in future planning by identifying trends among project categories, contract types, and design professionals.