The presentation and visualization of tradeoff solutions in many-objective optimization problems are difficult due to the large number of solutions in a hyperdimensional objective space. A recently proposed tool, known as aggregation tree (AT), can be used to analyze the degree of conflict between groups of objectives in a many-objective problem. In this paper, we present a case study on the internal permanent magnet motor design with seven objectives. The results show that the AT provides useful information about objective relationships (in accordance with the common knowledge of physics) as well as guidance in the reduction of objectives.