Consider a M/<G, G>/1(N) production system with order-selection and switch-order.Under this system, it is assumed that order-avrrivals are Poissonian, processing time is independent of the reward of orders, production capacity is variable and finite backlog is allowed.This paper formulates the two problems of optimizing the long-run average return as semi-Markov decision processes, and discusses a class of the 2-level control problem of job-shop production system.Finally, a numerical example is given.