Institute of Transportation, MOTC

Chi-Pin.Chang, 2001.06
Institute of Traffic and Transportation, National Chiao Tung University

　　“Single order picking ” and “ Batch picking ” are two commonly used methods which is widely adopted by most distribution centers nowadays.

　　“ Batch picking” is aim at rising picking efficiency by means of combining identical items in distinct orders and picking them altogether to reduce picking time and minimizing the distance of traveling.

　　Current “Batch picking” typically applies one conventional order batching method which sets minimized traveling distance as the optimal solution of order batching, not taking batch picking-generated sorting works into consideration. Solutions obtained based on such method are not capable of manifest the efficiency- rising capability of “Batch picking” method when factors like business cycle, new retail point setting, which may vary “EIQ” of orders, are taken into account. Under such conditions, current ”Batch picking” sometimes might be even less efficient than “Single order picking”.

　　In order to solve previous mentioned problems, this research applies mathematical non-linear programming method which sets minimized picking time and sorting time as the target solution of order batching equations. Also we constituted order-batching model that take picking and sorting into consideration, and developed two heuristic problem-solving methods called “MOTC” and “MOTC +SMD”. A real distribution center is selected for case study in which relevant data is collected and the results solved by the four methods are compared. A sensitivity analysis is also conducted in this study. It reveals that these two methods outperformed “Single order picking” and “SMD” batch picking in both real world cases and sensitivity analysis of parameters (including EIQ)-varying situations.