A new 'building block' for performance evaluation of queueing networks with finite buffers

We propose a new 'building block', for analyzing queueing networks. This is a model of a server with a variable buffer-size. Such a model enables efficient analysis of certain queueing networks with blocking due to limited buffer spaces, since it uses only product-form submodels. The technique is extensively tested, and found to be reasonably accurate over a wide range of parameters. Several examples are given, illustrating practical situations for which our model would prove to be a useful performance analysis tool, specially since it is simple to understand, and easy to implement using standard software for closed queueing networks.