The Last Planner System (LPS) is a tool for project planning and control, and is an important contribution from Lean Construction. LPS focuses on scheduling, task coordination and time management. Uncertainty Management (UM) is a key element in Project Management, where uncertainty is the totality of opportunities (potential upsides) and risks (potential downsides). UM addresses all types of uncertainty (related to cost, time, quality, scope, safety, customer satisfaction, company reputation, etc.). The aim of UM is to exploit the opportunities and reduce the risks. Two construction companies involved in this research are working with both LPS and UM. One has extensive experience with LPS, but less experience with UM. The other has extensive experience with UM, but less experience with LPS. Two questions are raised and discussed in the paper: 1. Could project planning and control be improved by an integration of LPS and UM? 2. If yes, how could LPS and UM be integrated to improve project planning and control? The paper proposes a conceptual model where UM tools are integrated in the plan and meeting structure of LPS. The model is to be tested in forthcoming case studies.