Using Reasons for Non-Compliance to Assess Project Performance in the Last Planner System

Abstract

The Last Planner System® (LPS) follows a systematic process of planning and control, in which compliance to short-term commitments is followed weekly and Reasons for Non-Compliance (RNC) are traced for each commitment not accomplished. While most project managers pay close attention to the evolution of the Plan Percent Complete (PPC) indicator to assess project performance, many projects make little or no use of historical data regarding RNCs. The aim of this research is to use quantitative RNC measurements to detect if projects with successful schedule accomplishment present significant differences in their number of RNC, their composition and impact. We gathered weekly information from 23 complete Chilean industrial construction projects and used the Schedule Performance Index (SPI) and Schedule Deviation (SD) at completion to categorize projects into two success groups. We compared LPS compliance indicators between the two groups, such as the Plan Percent Complete (PPC), and RNC metrics, such as their Relative Importance Index (RII), the percentage of internal RNC and the percentage of RNC caused by the main contractor. We found that RNC metrics present significant differences between the groups and can help project managers to establish actions for continuous improvement.