Production process evaluation for earthworks

Production in earthworks projects is a continuous process of strictly sequenced operations performed by heavy machinery on site. The Production Process Evaluation (PPE) index was developed to evaluate these types of processes by quantifying waste in the bottleneck operation. The PPE index is the ratio of the actual production volume to the theoretical maximum production volume, and it is calculated by assessing value adding and non-value adding times, actual and theoretical throughput, and shift durations. These are computed using data obtained from machine control systems linked to the roadel information schema, which represents continuous products and processes. The PPE index was implemented on a case study of a water reservoir construction project. The spreading operation was identified as the bottleneck in the process, based on the high levels of inventory waiting for the operation, the high capacity utilization in the operation and the low capacity utilization of the predecessor and successor operations. The PPE index ranged from 45% to 54% during the three weeks of the case study and indicated high levels of waste in the bottleneck and a lack of production management.