A lot of logistic activities are outsourced to focus on core competencies and to utilize the special know-how of service providers. This is especially valid for the outsourcing of packaging and international shipping processes. While several research studies cover the areas of make-or-buy and outsourcing in general only few publications deal with controlling of the implementation processes after the decision to outsource spare part logistics has been taken. Using the example of an outsourcing project of the Schleifring-Group, the success factors are analyzed. It is demonstrated how to implement an effective realization controlling and how planned improvements can be ensured.