Large organizations are increasingly recognizing the benefits of enterprise architecture, and heavily investing in it. However, many of those organizations struggle to be truly effective with architecture. In order to determine points of improvement, we have developed an approach for assessing an organization on its architecture effectiveness. Our approach differentiates from existing assessment models by considering multiple perspectives. It makes a distinction between the level of thinking about architecture, and the level of practicing it. It also gives insight in the (mis)alignment between IT and business oriented architecture functions. In this paper we describe the practical application of our assessment approach at a global financial services company.