Finding the Needle in a Haystack: Using Treemaps to Analyze Supplier Performance

Supplier evaluation is critical to managing an organization\´s supply base. Key to that evaluation is portraying the information graphically. Organizations with large supply bases find traditional methods are overwhelmed with large datasets. A tier 1 automotive supplier\´s quality system tracked eight performance measures for its many divisions and plants within the divisions. Each plant had a multitude of suppliers. Even when pivot tables, and pivot charts were used, the effective representation of that information wasn\´t accomplished through spreadsheets. Treemapping is a data visualization technology that makes efficient use of space and allows very large hierarchies to be displayed in their entirety. It sorts data using a user-defined hierarchy and displays data to meet the user\´s needs and decision making style. This paper provides a case study on the use of treemaps as a supplier performance rating system. The system was presented to users of the Excel-based system and their perceptions and evaluations of the treemap system were analyzed. They found the treemap system provided them with better information, made their job easier, and allowed for a full representation of supplier performance. Users were also appreciative of the ability to "drill down" on details of specific suppliers.