Network Calculus is a powerful mathematical theory for the performance evaluation of communication systems; among others it allows to determine worst-case performance measures. This is why it is often used to appoint Quality of Service guarantees in packet-switched systems like the internet. The main mathematical operation within this deterministic queuing theory is the min- plus convolution of two functions. For example the convolution of the arrival and service curve of a system which reflects the data’s departure. Considering Quality of Service measures and performance evaluation, the convolution operation plays a considerable important role, similar to classical system theory. Up to the present day, in many cases it is not practical and simple to perform this operation. In this article we describe approaches to simplify the min-plus convolution and, accordingly, facilitate the corresponding calculations.