Aggregation of hospital business processes

There are estimates that up to 30% of hospital costs are due to inefficiently coordinated hospital processes. As a result many hospitals have tried to model and to reengineer their business processes. These efforts have very often been abandoned, because the normally constructed total models of hospital processes could hardly cope with the rapid technological and medical progress as well as with changing staff. We discuss approaches for a qualitative and quantitative process modularization which improve the understanding of processes and enables better planned simulations. Various methods are discussed which allow a qualitative modularization on the basis of a disaggregated process graph. To cope with this modularization numerically simple semi-stochastic formulas are developed for the calculation of expected values and variances of cycle times and costs from micro-data up to the modular level. Thus a qualitative as well as quantitative discussion of hospital business processes on the modular level become possible.