关于商品存储场所任务的成熟方针。控制问题涉及到现实商品的顺序，安排与工艺路线的
变动。
规划与控制判断取决于战略管理判断与财产目录管理。战略管理确定了长期的目标并
且 它构成了供应链机构与仓库的设计。财产目录管理决定了多少数量的哪个产品被保存在
仓库与什么时候装 运到达。
理性的财产目录管理可以降低详细目录的程度与由此提升仓库运转的效率。回顾财产
目录模型，考虑到总体详细目录的数量，我们将他们分类为HARIGA与JACKSON。由于这些
模 型牵涉到财产目录与仓库运转，这些模型确立了一座介乎于入仓与详细目录管理领域的
桥梁。
由于战略判断有着一段长时期的影响，这些判断有着高度的不可靠性。典型的方法是
用于解决基于需求估 计的随机与模拟模型问题。规划问题涉及到中间时期与考虑其间存在
的情况。规划规则系统是基于它的局 部数据，它试图找到一个高质量平均成果的解决方法。
控制规则系统基于现实数据并且试图找到一个高质 量成果的解决方法。最优的组合方法也
是适合于解决规划与控制问题的。案例研究已经表明可以通过应用 理性的规划与控制方法
来相当大的改进生产力。
2．仓库运转的规划
在这部分， 我们主要集中在策略层储存场所任务的问题。成熟水准的步骤，是作为一
个供应与收回商品场所选择的架 构。在这些程序中，对于中期的反映是对于过去需求模式
的评价。由于储存场所任务的问题自始自终都是 比较棘手的，我们提出将储存场所规划步
骤分4阶段的等级体系。
储存场所规划步骤： 1．入库系统中产品的分配；2．关联产品的群集；3．入库系统中的协调工作量；4．产
品储存场 所选择任务。
我们将在2.1部分与2.4部分中论述这些资料。
2．1入库系统中产品的分配
大部分大型的仓库拥有不只一种入库系统。每种入库系统都是特 别基于尺寸，重量，
形状，不可储藏性，体积，需求率，采购量，运输量，储存模式等需求特征产品组装 备的。
此外，许多仓库采用分散的系统或区域用于汇单采购与货物存储。无论前部区域的产
品何时耗尽都可以在储备区中补充。一个众所周知的前部储备机构是低标准的人工汇单采
购与包含货物储 备的高标准储藏货架。
BOZER用更高层区域与前部区域处理分裂货物架的问题。他采用CHE BYSHEV传导期与
固定采购期用于所有的前部区域存储单元。他指出分散的储备区域情况是正常的。 他同样
研究了可变的储藏单元型号与远程储备区域的案例。他通过分解推导出了用于前部区域产
品的潜在利用与存储单元采购期收支平衡的重要性。
HACKMAN与ROSENBLATT提出了从 储备区域汇单采购模式的可能性。相应地，应当从前

部区域中采购产品与如何 为每样产品分配空间的问题产生了。目标是减小汇单采购与补充
的总费用。他们认为补充产品中的再补充 经验与分配数量无关。他们推导出一个有效存储
空间中理想产品数量作用的解析表达式。他们提出一个基 于背包的启发：给持续减小储金
花费的前部区域中分配数量，并且直到满为止。

A literature survey on planning and
control of warehousing systems
We present a literature survey on methods and techniques for the planning and
control of warehousing systems. Planning refers to management decisions that
affect the intermediate term (one or multiple months), such as inventory management
and storage
location assignment. Control refers to the operational decisions that
the short term (hours, day), such as routing, sequencing, scheduling and
order-batching. Prior to the literature survey, we give an introduction into
warehousing systems and a classification of warehouse management problems.
1. Introduction
1.1. The increasingly busy warehouse
Gudehus [1] and Graves [2], Hausman [3] and Schwarz [4] introduced the design,
planning and control of ware- housing systems as new research topics. The operation
of
warehousing systems has received considerable interest in the literature ever
since. It is not surprising that the research on warehousing systems gained
interest in the 1970s, since this was the era that management interest shifted
from productivity im- provement to inventory reduction. The introduction of
information systems made this strategy possible, with Manufacturing Resources
Planning (MRP-II) as a notable example. From Japan a new management philosophy
emerged: Just-In-Time (JIT) production. JIT attempts to achieve high-volume
production using minimal inven- tories of parts that arrive just in time. These
new devel- opments demanded from warehouses that low volumes be delivered more
frequently with shorter response times from a significantly wider variety of Stock
Keeping Units (SKU's). The new interest in quality forced warehouse managers to
re-examine their warehouse operation from the viewpoint of minimizing product
damage, establish- ing short and reliable transaction times and improving
order-picking accuracy. Current trends in warehousing and distribution logis- tics

are supply chain management and E?cient Consumer Response (ECR). Supply chain
management and ECR pursue a demand-driven organization of the supply chain
with small inventories and reliable short response times throughout the supply
chain. All deliveries are driven by the sales downward in the supply chain. Such
an organization requires a close cooperation among the companies in the supply
chain and the immediate feedback of sales data. Nowadays, information technology
enables these developments through Electronic Data Interchange (EDI) and software
systems such as the MRP-based Enterprise Resources Planning (ERP) systems and
Warehouse Management Systems (WMS). The new market forces have the
operation of warehouses tremendously. On the one hand, they demand an increased
productivity. On the other hand, the rapidly
changing market imposes financial risks upon the introduction of capital
intensive high-performance warehousing equipment which may be di?cult to
re-configure or discard. Hence, there is a great need for sophisticated techniques
that provide a dependable basis for adequate planning and control of warehouses
in such complex this paper we present a survey of methods and models
that have appeared in the literature for the planning and control of warehousing
systems. In the remainder of Section 1, we discuss warehousing systems and
warehouse management. In Sections 2 and 3 we discuss the literature on planning
and control issues, respectively. Finally, in Section 4 we end with conclusions
and suggestions for future research.
1.2. Warehousing
Warehousing involves all movement of goods within warehouses and Distribution
Centers (DC's), namely: *Current address: Berenschot, P.O. Box 8039, 3503 RA
Utrecht,
The Netherlands. Tel.: +31302916822, Fax: +31302916826
0740-817X ó 1999 ``IIE''
IIE Transactions (1999) 31, 751±762
receiving, storage, order-picking, accumulation and sorting and shipping. An
order lists the SKU's and quantities requested by a customer or by a production
unit, in a DC or a production warehouse, -picking is the process
of gathering SKU's that have been requested in an order at one an
order-picking operation, the order pickers may pick one order at the time (single
order-picking). A higher e?ciency may be achieved by picking multiple orders
simultaneously (batch picking). Furthermore, orders may be picked from separate

warehousing systems or separate zones within systems. Consequently, in such
situations the orders need to be sorted and accumulated to establish order
integrity. Orders may be sorted during the order-picking process (sort-while-pick)
or afterwards (pick- and-sort). Warehousing systems may be classi?ed into three
groups:
(1) Picker-to-product systems.
(2) Product-to-picker systems.
(3) Picker-less systems.
In a picker-to- product system, manual order-pickers ride in vehicles along
the pick positions. There is a wide variety of vehicles available from manually
propelled vehicles to motorized vehicles which also enable vertical movement for
order- picking from elevated positions. Instead of a vehicle, a system may also
include a take-away conveyor for picked products (pick-to- belt).Examples of
product-to-picker systems are the Auto -mated StorageRetrieval System (ASRS)
and the ASRS is a high-bay warehouse with StorageRetrieval (SR)
machines or automated stacker cranes that perform the storage and retrieval of
storage modules (such as pallets or containers). A miniload ASRS is an ASRS
especially equipped for the storage and order- picking of small items. A carousel
consists of storage positions that rotate around a closed loop thereby delivering
the requested SKU's to the order-picker. Carousels may rotate horizontally
(horizontal carousel) or vertically (vertical carousel).Picker-less systems make
use of robot-technology or automatic respect to product retrieval
we distinguish unitload retrieval systems and order-picking systems. In a unitload
retrieval system complete unit-loads are retrieved.
Accordingly, the vehicles either perform one stop (storage or retrieval) or
two stops (storage followed by a retrieval)in a single trip. We refer to these
trips as a single-com -mand cycle and a dual-command cycle, respectively. In an
order-picking system typically less-than-unit-load quantities are picked, so that
there will be multiple stops per trip (multi-command cycle).
1.3. Warehouse management
We may establish high quality solutions for warehouse management by
decomposing the task into a number of hierarchical subproblems. A well-de?ned
hierarchy will prevent local optimization without considering the global context.
A broad hierarchy of management decisions is the following ([5]):
? Strategic decisions.

? Tactical decisions.
? Operational decisions.
Strategic management decisions are long-term decisions and concern the
determination of broad policies and plans for using the resources of a company
to best support its long-term competitive strategy. Tactical management decisions
primarily address how to e?ciently schedule material and labor within the
constraints of previously made strategic decisions. Operational management
decisions are narrow and short-term by comparison and act under the operating
constraints set out by the strategic and tactical management central
themes of this survey are planning and control of warehousing systems. Planning
of warehousing systems refers to the policies which are developed at the tactical
level concerning the assignment of goods to storage locations. Control problems
concern the actual sequencing, scheduling and routing of the movement of goods.
Planning and control decisions are subject to strategic management and inventory
management. Strategic management de?nes long-term goals and it constitutes the
supply chain organization and the warehouse design (for a review of warehouse
design models we refer to Ashayeri and Gelders [6]). Inventory management decides
which products are kept in storage in what quantities and when shipments arrive.
Intelligent inventory management may reduce the inventory levels and thereby
improve the e?ciency of the warehouse operation. For a review of inventory models
that consider the total inventory quantity we refer to Hariga and Jackson [7].
Since these models both involve the inventory and the warehouse operation, the
models establish a bridge between the ?eld of warehousing and the field of inventory
strategic decisions a long period, these decisions face
high uncertainties. Typical methods used for solving such problems are stochastic
models and simulation, based on demand estimates. Planning problems concern the
intermediate period and consider an existing situation. Planning algorithms are
based on historical data and attempt to ?nd solutions with a high quality average
performance. Control algorithms are based on actual data and attempt to @nd
solutions with a high-quality performance. Combinatorial optimization techniques
are well suited for solving planning and control problems. Case studies have shown
that considerable productivity improvements are possible by applying intelligent
planning and control policies [8±10]. 752 van den Berg
2. Planning of warehouse operations
In this section we focus on the storage location assignment problem at the

tactical level. The procedures that are developed at this level, serve as a
framework for the actual location selection for incoming goods. In these procedures,
the behavior on the intermediate term is estimated by historical demand patterns.
Since the storage location assignment problem will be intractable as a whole, we
introduce the hierarchical four step Storage Location Planning e
Location Planning Procedure
1. Distribution of products among warehousing sys-
tems.
2. Clustering of correlated products.
3. Balancing of workload within warehousing systems.
4. Assignment of products to storage locations.
We discuss relevant literature on the successive steps in Sections 2.1 to 2.4.
2.1. Distribution of products among warehousing systems
Most large warehouses contain more than one type of warehousing system. Each
warehousing system is especially equipped for a speci?c group of products based
on their characteristics, such as: size, weight, shape, perishability, volume,
demand rate, pick sizes, delivery quantity, type of storage module, et
rmore, many warehouses use separate systems or areas for
order-picking (forward area) and for bulk storage (reserve area). Whenever a
product in the forward area has been depleted, it is replenished from the reserve
area. A well- known forward-reserve con?guration is a
storage rack where the lower levels are used for manual order-picking (forward
area) and the higher levels contain the bulk storage (reserve area).Bozer [11]
treats the problem of splitting a pallet rack into an upper reserve area and a
lower forward area. The author assumes Chebyshev travel times (i.e., the travel
time of the pallet truck is the maximum of the isolated horizontal and vertical
travel times) and a ?xed pick-life for all unit-loads in the forward area. He shows
when a separate reserve area is justi?ed. He also studies the case with variable
unit-load sizes and a remote reserve area. He analytically derives the break-even
value for the picklife of a unit-load, which is of potential use in deciding which
products to consider for the forward area. Hackman and Rosenblatt [12] present
a model where order- picking from the reserve area is possible. Accordingly, the
question arises which products should be picked from the forward area and how much
space must be allocated to each of these products. The objective is to minimize
the total costs for order-picking and replenishing. The authors assume that one

replenishment trip su?ces to replenish a product, irrespective of the allocated
quantity. The authors derive analytic expressions for the optimal product
quantities as a function of the available storage space. They present a
knapsack-based heuristic that assigns these quantities to the forward area in
sequence of decreasing cost savings until it is full.