^pof;
Business;
Administration,;
Hannam;
University,;
Daejeon,;
306-791,;
Republic;
of;
Korea;
^pof;
Industrial;
and;
Systems;
Engineering,;
KAIST,;
Daejeon,;
305-701,;
Republic;
of;
Korea;
预防性维护; 生产状态; 生产系统; 随机冲击; 恶化; 维修水平; 平均成本; 产品数量;