subsystems, and also its processes. The proposed model is applied to compute the global cost Malmquist productivity index for … measuring the productivity changes of network system and each of its process between two time periods. This index is circular …. Furthermore, we show that the productivity changes of network system can be defined as a weighted average of the process …

, we use the virtual frontier method to calculate the Malmquist Productivity Index (MPI), which avoids the inability of DMU …