The objective of the thesis is to display how the yearly activity of a Business Controller can be described through a Plan-Do-Check-Act cycle (also referred to as Deming cycle), resulting in improved performance and timely reporting. In particular, the activities were performed in Tetra Pak® Packaging Solutions inside the Supplier Management framework. The thesis will start with the necessary introduction on the company and its product portfolio since it is propaedeutic to better understand the activities of the Business Controllers. Then I will start to show how each yearly task can be inserted in PDCA loop, moving from the Plan phase in which the yearly target is set to the Check phase in which the controllers perform the variance analysis using different tools.