An important part of trying to improve a business is to describe and visualize it. A common theme in many recent approaches to development work, e.g. Business Process Re-engineering (BPR), is to concentrate on important processes in the business. Often, the models used in such a context are limited to a specific type of process models. In order to be better prepared for different problems, possibilities, and other issues in the business, there is a need for also covering additional perspectives. This paper presents four basic model types, each based on a different perspective on the business. Two of the model types share a focus on process: behavior models (e.g. flowcharts) and transformation models (e.g. process graphs). The other two share a focus on content: Category models (e.g. data models) and Factor models (e.g. goal models).