As a company, you are often faced with the challenge of carrying out several projects at the same time. Projects are often outsourced to external companies to save resources. In this context, it is necessary to specify in advance exactly which criteria are used to determine the payment at the end. There is no method that can be used to the same extent for all projects. However, some methods have been established over several decades, others less so. This paper provides an overview of existing software metrics that can be used for supplier management. In this thesis, comparisons and evaluations of the different methodologies are made and evaluated. The aim is to make the most accurate predictions possible, taking into account factors relevant to software technology. One has to be aware, that the metrics are estimation methods and therefore a certain discrepancy between the assumption and the result is to be expected. By means of precise calculations, one hopes for the smallest possible deviation. In the course of a survey among well-respected companies in Austria, the procedures and methods of these companies were evaluated and the results were incorporated into the work. The survey included specific questions regarding awareness, use and procedures of the methods and was conducted largely by managers from the respective departments.