Since the ability to precisely forecast the project’s total duration is of great importance for successful project management, a variety of approaches have been developed to address this issue over the last few decades. Recently, the Earned Duration Management (EDM) method has been proposed for monitoring schedule performance of a project and forecasting its total duration. It has been claimed that EDM method provides more accurate project duration forecasts compared with other EVM based approaches such as Earned Schedule Method (ESM). However, its potential and validity has not yet been adequately tried and tested. Therefore, in this paper, we extensively evaluate and compare the accuracy and reliability of EDM and ESM duration performance indicators to forecast the project’s total duration on a vast variety of simulated projects with various network topology or structures through the Monte Carlo simulation technique. Moreover, the impact of correlation between time and cost profiles as well as the effect of degree of progression toward completion of the project on the forecasting accuracy of the above-mentioned methods are examined. The findings conclusively support Earned Duration Management as a preferred approach compared with Earned Schedule Method regardless of the network topology or completion stages of the project. Furthermore, forecasting accuracy of EDM vs. ESM considering correlated/ uncorrelated profiles of time and cost also yields overall dominance of EDM in the results.