Cost Overrun and Time Delay Risk Assessment in Local Road Bridge Construction using Fuzzy Inference System

Abstract

Motorable Local Road Bridge Programm is a project implemented by Department of Local Infrastructure initiated from February, 2011. Since its initiation, construction of 346 bridges have been completed through this program using unit rate NCB contract. The current phase of this project has set target for completing construction of additional 200 bridges in coming four years. The aim of this research is to assess and analyze the risk factors resulting in cost overrun and time delay of completed bridges and use this knowledge for mitigation of risks in future projects. Risk factors were identified and classified through literature review. A fuzzy inference system based model was developed using MATLAB for calculation of risk indices based on questionnaire survey. A set of 57 bridges were sampled from the entire population for validation of model. The study identified Government regulations/contract awarded to lowest bidder, inadequate budget allocation and unexpected ground condition as the highest ranked risk factor causing cost overrun and time delay in local road bridge construction. Risk management plan including risk response planning for mitigation was prepared for the principal risk factors. Risk indices obtained from the study can be used as weightage factors for developing a neuro-fuzzy based prediction model.