E-assessment enjoys growing attention in university courses and is increasingly applied. Although automated feedback and grading for creative question types is a complex endeavor, more and more tools are developed to support e-assessment for miscellaneous question types. This paper focuses on an automated assessment of UML class diagrams. While there are already tools which support the analysis of student solutions for UML class diagrams, they only provide feedback on a low level. This paper motivates a need for assessing advanced computer science skills. For this, an analysis of student exams is conducted, focusing on exams which instruct the student to choose an appropriate design pattern for a given use case. Further, a prototype is presented which allows for an identification of design patterns, as a first step of a UML assessment tool. For this purpose, an algorithm for error-tolerant subgraph isomorphisms is adopted and extended which deals with multiple design patterns at the same time in order to match them to the students' solutions. Since it is possible to model design patterns in different sizes, a pattern template notation is presented which enables to specify the possible variants of each design pattern. A new algorithm then translates the pattern templates to be understood by the adopted matching algorithm. Finally, the identification process is evaluated empirically, showing the merits and the limitations of this approach.