A Forecast and Mitigation Model of Construction Performance by Assessing Detailed Engineering Maturity at Key Milestones for Offshore EPC Mega-Projects

Abstract

The main subject of this research is to develop a forecast and mitigation model of schedule and cost performance during a detailed engineering stage of offshore engineering, procurement and construction (EPC) projects. The weight factors of major elements in detailed engineering completion rating index system (DECRIS) were measured using a fuzzy inference system (FIS) and an analytic hierarchy process (AHP). At five key engineering milestones, from an EPC contract being awarded to the start of construction, detailed engineering maturities were assessed in fourteen historical offshore EPC projects using the DECRIS model. DECRIS cutoff scores for successful project execution were defined at the key engineering milestones. A schedule and cost performance was forecasted and validated through comparison of DECRIS and other models using statistical confidence of a fuzzy set qualitative comparative analysis (fsQCA) and a regression analysis. As a mitigation method for engineering risks to EPC contractors, engineering resource enhancement is recommended for trade-off optimization of cost overrun using a Monte Carlo simulation. The main contribution of this research is that EPC contractors could continuously forecast construction costs and schedule performance utilizing the DECRIS model, and could review the adequacy of engineering resources, assessing the trade-off between said resources and cost/schedule risk mitigation.

Using Text Mining to Estimate Schedule Delay Risk of 13 Offshore Oil and Gas EPC Case Studies During the Bidding Process

“…While there exist a multitude of studies modelling construction schedules, research on estimating schedules and predicting the potential delays for O&G project construction related to automated modelling are few. A detailed engineering completion rating index system model was developed and implemented to assist offshore EPC contractors for optimizing fabrication and construction work schedule with minimizing possibility of repetition of works [20,21]. Jo et al [22] developed a methodology of piping construction delay prevention to improve material procurement management and avoid shortage of piping materials and to minimize delays, by using the critical chain project management.…”

“…Note, this process of developing an SDRI scoring has precedence within existing literature, though the score has been given many names. The scoring method most similar to the presented SDRI models the project definition rating index (PDRI) by the Construction International Institute (CII) [44] and two papers on the Detail Engineering Completion Rating Index System (DECRIS) [20,21]. These two indexes are typically used by the project owner and EPC contractor to quantify the level of basic and detailed engineering maturity to determine whether the project can move to the next development stage by mapping PDRI scores and DECRIS score to project performances of schedule delay and cost overrun in the EPC execution stage.…”

“…Therefore, it is verified that the increase of project duration was predicted with an accuracy of 80.7% referencing that the difference between predicted and actual increase in project duration is only 2.3 months as summarized in Table 12. It is worthwhile to compare the schedule delay from the predictive model (SDRI) and the DECRIS model [20] to forecast construction duration delay, as Project M was used to verify model accuracy in both publications. The DECRIS model forecasted the construction schedule delay of about 8 months (i.e., 235 days), compared to about 14 months of schedule delay from the SDEM predictive model in this paper versus 12 months of actual measured delay [20].…”

“…It is worthwhile to compare the schedule delay from the predictive model (SDRI) and the DECRIS model [20] to forecast construction duration delay, as Project M was used to verify model accuracy in both publications. The DECRIS model forecasted the construction schedule delay of about 8 months (i.e., 235 days), compared to about 14 months of schedule delay from the SDEM predictive model in this paper versus 12 months of actual measured delay [20]. As can be seen, the presented SDEM model is more conservative and more accurate than the DECRIS model.…”

“…For example, the term "escape tunnel" likely has a greater impact on the schedule than "nozzle". While this remains a limitation, using count data to develop risk scoring has been used historically in the literature [20,21,33,44].…”