Recently, many of container terminal operates adopt an AYC(Automated Yard Crane) as yard container handling equipment in order to reduce costs and improve productivity. A container terminal that uses AYCs requires a remote worker to perform loading/unloading operation of AYCs safely. Generally remote workers are assigned to AYCs in the sequence of request of an AYC. Providing too many remote workers to operations of AYCs involves cost and not providing enough remote workers to operations of AYCs results in excessive waiting time of AYCs and external trucks. Therefore the effect of queueing in relation to the time spent by AYCs to access remote work services is an important issues of container terminal operators. In this study, the queueing characteristics of the remote workers operation is analysed using a multi-server queueing model. Considering the service level and waiting cost, we deals with how to determine the optimal number of remote worker. The validity of the proposed method was verified using actual field data and the sensitivity analysis has been performed.