Christoph G. Schuetz examines the conceptual modeling aspects of multilevel business processes without neglecting the implementation aspects. Furthermore, he investigates the advantages of hetero-homogeneous models for quantitative business process analysis. Multilevel models reflect the reality of many information systems. In this respect process-aware information systems are no exception. Multilevel models capture interdependencies between business processes at different organizational levels and allow for a convenient representation of business process variability which, in turn, facilitates the analysis of business processes across different organizational units.