Integrated CO2, cost, and schedule management system for building construction projects using the earned value management theory

Although the construction phase in a building's life cycle is relatively very short, the density of the CO2 emissions in the construction phase is very higher than that in the other phases (i.e., operations and maintenance phase). However, there was little research on scheduling, monitoring, evaluating and forecasting CO2 emissions based on the construction schedule. To address this challenge, this research aimed to develop an integrated CO2, cost and schedule management (ICCSM) system for building construction projects using the earned value management theory. The proposed ICCSM system consisted of five steps: (i) definition of the project scope and organization; (ii) project planning and scheduling; (iii) estimation and budgeting of the CO2 emissions and construction costs; (iv) establishment and weighting of the project performance measurement baseline; and (v) monitoring and forecasting of the project performance. The case study showed that the ICCSM system can evaluate and forecast the project performance earlier and more accurately, based on the construction schedule, (i) when integrated weighting was implemented, the project performance can be estimated faster (i.e., one day earlier); and (ii) when 0.8 × (cost performance index) + 0.2 × (schedule performance index) was implemented as the index for calculating an estimate at completion, the project performance can be more accurately predicted (i.e., error rate = −0.24%). The ICCSM system could allow a project manager to monitor and forecast CO2 emissions and costs based on the construction schedule, simultaneously.