In this paper, a four-stage service model is constructed by combining M/M/1, MX/M/1 and M/MB/1 queuing systems. In addition, the immediate scheduling strategy and its algorithm are presented in detail, and the computing accomplished scheduling strategy and its algorithm are proposed. Approaches for computing the receiving time, preprocessing time, operating time and transmission time of operation requests that are based on various queuing systems are discussed, and the response time is calculated by adding these times together. Finally, the response times under the two scheduling strategies are obtained by simulating the models numerically, and the results demonstrate that the proposed computing accomplished scheduling strategy outperforms the immediate scheduling strategy.