Predicting the project time and costs using EVM based on gray numbers

Purpose: The purpose of this paper is to determine the project completion time and cost under non-deterministic conditions using interval gray numbers (IGNs). Design/methodology/approach: The earned value management (EVM) method based on the IGN has been developed. Findings: The EVM method based on the IGN has been verified by a numerical example that can be applied to construction projects. Practical implications: The EVM method, based on the gray numbers, reduces the budget and time shortage risk. Also, using this method, the managers would not be restricted to provide very exact values in their progress reports in the non-deterministic conditions. Originality/value: One notable and significant point in all projects during the execution process is to estimate the project completion time and cost. However, non-deterministic conditions for both planned and actual physical completion percentage of projects have not been considered for predicting the project completion time and cost in the literature. Therefore, the novelty of this paper is the prediction of project completion time and cost under non-deterministic conditions using IGN.