Analysis and optimal design of discrete order picking technologies along a line

Abstract

Abstract:Order picking accounts for most of the operating expense of a typical distribution center, and thus is often considered the most critical function of a supply chain. In discrete order picking a single worker walks to pick all the items necessary to fulfill a single customer order. Discrete order picking is common not only because of its simplicity and reliability, but also because of its ability to pick orders quickly upon receipt, and thus is commonly used by e-commerce operations. There are two primary ways to reduce the cost (walking distance required) of the order picking system. First is through the use of technology-conveyor systems and/or the ability to transmit order information to pickers via mobile units. Second is through the design-where best to locate depots (where workers receive pick lists and deposit completed orders) and how best to lay out the product. We build a stochastic model to compare three configurations of different technology requirements: single-depot, dual-depot, and no-depot. For each configuration we explore the optimal design.

Exact route-length formulas and a storage location assignment heuristic for picker-to-parts warehouses

“…Given a realization of the X k 's, we define an order as O fkjk 2 K; X k ¼ 1g. We assume all items can be stored in any storage location, as is common in literature (e.g., Le-Duc and De Koster, 2005;Eisenstein, 2008;Pan et al, 2012). Let A be a m  n matrix denoting a storage location assignment, where a ij gives the index of the item assigned to location j in aisle i, and a i ¼ ða i1 ; .…”

“…We assume the capacity of the order picker is sufficient to fulfill any order, as is common in literature (see, e.g., Jarvis and Mcdowell, 1991;Eisenstein, 2008). We consider four routing methods, each of which is indicated by a single letter in the formulas:…”

“…Since we assume demand for items to be independent, X k are independent Poisson trials with probability p k PðX k ¼ 1Þ; 8k 2 K. The demand distribution is completely described by the set fp k ; k 2 Kg. In the context of storage location assignment this demand model is also used in, for example, Jarvis and Mcdowell (1991) and Eisenstein (2008). Given a realization of the X k 's, we define an order as O fkjk 2 K; X k ¼ 1g.…”

“…Therefore, we condition on the event that the order has at least one pick item. Similar to Eisenstein (2008), define P to be the probability that an order is non-empty:…”

Literatür Araştırması: Sipariş Toplama Politikaları ve Otomatik Depolama ve Boşaltma Sistemleri(AS/RS)

“…Bu çalışmada farklı sipariş toplama ele alınmıştır. Çalışmada sipariş maliyetini azaltmak için öneriler getrilmiştir [14]. Ho ve Su iki koridorlu olan bir sipariş toplama deposu için sipariş gruplama metotlarını ele almışlardır.…”