This document discusses using positive investigations to understand what works well. It provides context on Laing O'Rourke's work activities and focuses on understanding success rather than failures. The document outlines a simple model using 4 questions to engage with people after a task is completed to identify what made the work successful and how to do more of it. An example is provided of a positive investigation done after a tree removal task to understand what contributed to it going well. The overall aim is to improve culture, productivity, quality and relationships by learning from successful work experiences.