What Types of Problem-Solving are Used in the Last Planner System?

The paper presents the framework of Four Types of Problems, published by Art Smalley in 2018, and uses the framework to discuss how problems are solved in the Last Planner System.A problem is defined as any outcome other than the desired performance at any given time.The framework categorizes problems and problem-solving into four distinct types: Troubleshooting, Gap from Standard, Target Condition and Open-ended.The first two types are about maintaining a current standard (to reach the bar), while the two latter are about raising the standard (to raise the bar).The paper finds that Troubleshooting is in fact a dominant way of solving problems in the Last Planner System.Given that Last Planner is generally held to be a pro-active planning approach where tasks are being made ready for execution, this might seem surprising.Among other things, the reason lies in the project-based nature of construction.