This paper aims to examine the relationships and delimitations between maintenance management (MM) and physical asset management (AM) concepts. There are several standards, e.g., ISO 5000*, DIN 31015, and DIN EN 13306, which define the basic terms connected to maintenance and asset management. However, they lack a clear differentiation between the two terms, and in the scientific literature, they are often used interchangeably. To gather an in-depth understanding of the usage of the two terms, a literature review (LR) was conducted based on different search strings around MM and AM. Using the principles of Design Science Research (DSR), a model was created to describe the morphologies of companies on the spectrum from MM to AM. For validation, data from assessment- and optimization projects with Austrian and German industrial companies in the fields of MM and AM was used. The results are a proposal for a differentiation scheme by the authors and a classification method that helps to understand the differences between MM and AM.