We consider a bulk arrival, bulk service queueing system. Customers ar
e served in batches of r units if the queue length is not less than r.
Otherwise, the server delays the service until the number of units in
the queue reaches or exceeds level r. We assume that unserved custome
rs may get impatient and leave the system. An ergodicity condition and
steady-state probabilities are derived. Various system characteristic
s are also computed.