In this book we studied the different queueing systems with N-Policy. Steady state equations governing the queueing system are developed and solved using probability generating funtions to obtain the steady state probabilities corresponding to different states of the server. Expected queue length when the server is in different states are derived and expected waiting time in the queue is obtained through heuristic approach. Sensitivity analysis is performed to be determine the optimal threshold of N based on changes in the system parameters and cost elements for the geometric arrival batch size distribution.