A business use case (BUC) model is the higher abstraction of the system use case model. In a BUC, business actors with specific business goals interact with other business actors. It is primarily an external view of the business model or area of interest. A system use case diagram, on the other hand, illustrates the domain from an internal point of view. This article explains how business use cases can help business architects, helping them to discover quality high level business requirements.