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.