Sharma, A. and Trivedi, J. (2021). “Application of Information Theory in Last Planner ® System for Work Plan Reliability.” Proc. 29 th Annual Conference of the International Group for Lean Construction (IGLC29), Alarcon, L.F. and González, V.A. (eds.), Lima, Peru, pp. 727–736, doi.org/10.24928/2021/0147, online at iglc.net. Production Planning and Control 727 APPLICATION OF INFORMATION THEORY IN LAST PLANNER ® SYSTEM FOR WORK PLAN RELIABILITY Anjali Sharma 1 , and Jyoti Trivedi 2 ABSTRACT Last planner system ® (LPS) is an effective tool for continuous monitoring and improvement of the planning. One of the main parts of LPS is the constraint removal discussion. Identifying and removing the constraints before the execution can influence the reliability of the plan and can ultimately improve the project performance. Previous research works have indicated the use of Information theory to quantify the effect of constraint removal discussion on the performance of the weekly work plan while using Percentage Plan Complete (PPC) as an indicator of work plan reliability and considering a limited range of constraints categories. Earlier studies have proved that Task Anticipated (TA) and Task Made Ready (TMR) are better indicators of the project duration than PCC. In this paper, the researchers have used information theory to assess the effect of the constraint removal discussion on PPC, TA, and TMR of the construction projects while considering a wider range of constraints. The results signified that the important constraint categories vary for improving PPC and improving TA & TMR. Identifying and discussing the main constraint categories could improve the work plan reliability indicators up to 18%. The framework can be used repeatedly and the results can contribute in improving the effectiveness of weekly meetings in the future. KEYWORDS Last planner ® system, constraint analysis, make-ready planning, work plan reliability, information theory. INTRODUCTION The last planner system was designed by Glenn Ballard and Gregory Howell using the action research approach in the early 1990s’. Construction professionals have been using it widely in the architecture, engineering, and construction (AEC) industry for over two decades. Unlike the critical path method (CPM) the LPS uses pull driven scheduling approach to improve the planning reliability (Dave, Hämäläinen, & Koskela 2015). One of the main features of LPS is the constraint removal discussion. Research works have proved that identifying and removing the constraints prior to the execution can influence the reliability of the look-ahead plan and ultimately improve the project performance (Hamzeh et al. 2015). 1 Masters Student, M.Tech Construction Engineering and Management, CEPT University, Ahmedabad, India, +91 7874 180 260, anjali.sh1303@gmail.com, orcid.org/0000-0002-7107-3616 2 Assistant Professor, Faculty of Technology, CEPT University, Ahmedabad , India, +91 9925 009 609, jyoti@cept.ac.in, orcid.org/0000-0001-5088-7939