Effective removal of constraints is critical in the Last Planner System (LPS)to improve work plan reliability. While removing constraints is important, it remains unclear to project managers about which types of constraint have the highest level of uncertainty and to what extent the constraint removal discussions are efficient for improving work plan reliability. This research uses a bridge project as an example to answer these research questions. The authors collected planning meeting minutes, look ahead plans, and production dataof11 weeks to analyze constraint removal discussions in weekly plan meetings and the associated Percent Plan Complete (PPC).Information theory method was used to calculate the amount of information gain and the information transmission efficiency for PPC improvement. Results show that Prerequisite Readiness is the most important constraint to discuss and contributes to 24% of the total information gain for PPC improvement. This constraint also has the highest information transmission efficiency of 36%, almost twice the average information transmission efficiency of the other constraints. The method proposed in this paper can be used repetitively on other projects and will help project managers to improve their meeting effectiveness in order to achieve higher work plan reliability.