A value stream map is a visual tool used in process improvement to analyze and optimize the flow of materials and information in a production system. It helps identify waste, inefficiencies, and areas for improvement by illustrating each step in a process, from the initial request to the final delivery of a product or service. By mapping out the entire process, teams can better understand how value is created and where delays or bottlenecks occur. This technique is often associated with methodologies like Lean and Six Sigma, which focus on enhancing efficiency and quality in various industries.