The increasing impact of services on economic wealth and income in high wage countries calls for a detailed examination of service productivity and complexity in current research projects. This paper describes the development of a measurement model of service productivity and complexity within the domain of medical service provision. While the measurement model of service productivity is partly literature-based, a novel construct is developed for service complexity. The reliability and validity of these constructs have been analyzed by a survey with 454 employees of German medical rescue service providers. Reliability of the construct is estimated by analyzing Cronbach’s alpha, average variance extracted, variance inflation factors and the significance, weights and loadings of the items. Furthermore, the relationship between the partial productivities (capacity, internal and external) as well as complexity and service performance is analyzed by using the structural equation modeling approach with partial least square method (PLS-SEM). The results indicate that the developed constructs have sufficient reliability, although the examination of validity highlights difficulties in quantifying service productivity and complexity. While a significant and substantial effect of internal and external efficiency on service performance could be proved, complexity influences performance only marginally and positively while capacity efficiency has no effect at all. Thus, further research is needed in order to foster the measurement model and to investigate possible nonlinear relationships between the constructs in more detail
