Due to the complexity and stochastic nature of automated warehousing system, items are usually queued up at I/O point. We introduce a storage/retrieval policy : dual-command. We present quick approximations to queueing phenomena under these policies. It is assumed that the storage and retrieval arrrival pattern follow the same poisson process. We also assumed that storage queue and retrieval queue being operated separately. The approximation attempts are performed under the proposed storage/retrieval policies after we derive S/R machine travel time distributions.

Abstract
 1. 서론
 2. 모형 정의와 대기행렬정책
 3. 대기행렬 현상 분석
  3.1. 창고상태에 대한 확률과정 분석
  3.2 서비스시간의 분포
  3.3 Vacation 시간의 분포
  3.4 성능평가 척도
 4. 수치계산 결과
 5. 결론
 참고문헌

• 장진익(충청대학 산업정보과) | Chang Jin Ick
• 김원중(아주대학교 산업정보시스템공학과) | Kim Won Joong