Warehouse Operations

What is Warehouse ? อ้างอิงจาก http://www.wisegeek.com A warehouse is a large building where goods are stored, and where they may be catalogued, shipped, or received, depending upon the type. Though in the past, many warehouses, often located in industrial areas sometimes next to major shipping ports, were teeming with workers, the modern warehouse may be either completely or totally automated depending upon how advanced the company is.

What is Warehouse ? Warehouses have existed for several centuries, and the word itself is not hard to understand. “Wares” were the things possessed by a seller and to house these in a central location meant your were storing your wares.getting in new products, and shipping out products already stored.

What is Warehouse ? Another important part of maintaining a good warehouse is keeping inventory of what products are presently in the warehouse, what has been shipped and what has been received.

Warehouse Functions Provide temporary storage Put together an order Serve as a customer service facility Protect goods Perform value added services Inventory

The Value Chain Firm Structure Human Resource Development Supporting Activities Technology Development Procurement Inbound Logistics Operations Outbound Logistics Marketing and Sales Services

Warehouse Functions - Warehouse organizes and repackages product - Product arrives packaged on a large scale and leaves packages on a smaller scale “The smaller the handling unit, the greater the handling cost”

Processes of reorganization of product Inbound Processes Receiving Put away/Storage Outbound Processes Processing customer orders Order-picking Checking Packing Shipping

Receiving Unloading and staging for put away Inspection (Sampling and/or 100%) Scanned for registering to Confirm its availability Confirm ownership Normally, receiving is accounted for about 10% of W/H operations cost.

Put-away “Before product can be put away, an appropriate storage location must be determined” “Where the product is stored is directly related to how quick and what cost to retrieve it later”

Put-away W/H manager must know at all time that: Which storage locations are available How large they are How much weight they can take After product is put away, its location must be recorded Cost of put away is about 15% of W/H operating expenses

Process of customer orders On receipt of customer orders the warehouse must perform checks such as to verify that inventory is available to ship The warehouse must produce a “pick list” to guide the order picking The order picking include assigning operators and sequence of order picking and shipping

Order Picking Order picking account for 55% of warehouse operations cost, it can be broken down to: Traveling 55% Searching 15% Extracting 10% Paper work and other 20% *% of total order picking cost

Order Picking Depend on type of storage and retrieval system Person-to-item Item-to-person Manual or ASRS Terminology used in order picking operations Pick-sheet or pick line Pick/visit Pick face Pick density (# of picks per foot of travel)

Order Picking Flow time is a main indicator for picking performance Short flow time can lead to better service and responsiveness Flow time depend on how large the unit load, serial or parallel pickers Number of pickers

Order Picking If the total work to pick and load a truck is small, one picker may be assign to each order If the orders to pick and load are large or span distant region, several pickers are needed to shorten the flow time

Order Picking For a warehouse that move a lot of small products for each of many customers, such as shipping to retail stores, order picking may be organized as an assembly line The assembly line needs to be balance using some line balancing techniques

Checking and Packing Packing can be very labor intensive Every item needs to be handled but with minimal walking Then, checking can be performed simultaneously to make sure completeness of order Incomplete order leads to return which is expensive

Checking and Packing Packing must aim at minimizing broken space when shipping Also, customers want orders in as few containers as possible to avoid excessive handling cost

Shipping Shipping generally handles larger units than picking Less labor intensive Goal is to minimize transportation cost Protect goods Ease load and unloading

Warehouse Management Systems -Highly automated system that runs day-to-day operations of a DC -Controls item putaway, picking, packing, and shipping -Features transportation management order management yard management labor management warehouse optimization

A WMS

Vendor-Managed Inventory Manufacturers generate orders, not distributors or retailers Stocking information is accessed using EDI A first step towards supply chain collaboration Increased speed, reduced errors, and improved service

Warehouse Management System (WMS) The main function of WMS are to track all product arriving and shipping out It most fundamental capability is to record receipt of inventory into the warehouse and register its shipment out (including financial transaction)

Warehouse Management System (WMS) Another important function are: Ability to do storage allocation Routing of material handling equipment Track every place that product can be stored Known as stock locator system

Manu Features of WMS Basic features Appointment scheduling Receiving Quality assurance Put away Location tracking Work-order management Picking Packing and consolidating Shipping

Manu Features of WMS High-end features Cycle counting Replenishment Yard management Labor management Value-added service Etc.

Manu Features of WMS WMS’s are extending their functionality to support activities in supply chain both upstream and downstream like: EXE technologies Manhattan Associates MARC Global System Swisslog Software etc

Materials Handling

Materials Handling Material handling is an activity that uses the right method to provide the right amount of the right material at the right place, at the right time, in the right sequence, in the right position and at the right cost

Materials Handling (Cont) Systems perspective 20-70% of product cost attributed to material handling

Unit Load Unit load - number of items or bulk material arranged so they can be picked up and delivered as one load Large or small? If large, cost/unit handled decreases But, depending upon cost of unitizing, de-unitizing

Unit Load (Cont) smaller unit load may be desired space required for material handling material handling carrier payload work-in-process inventory costs storage and return of empty pallets or containers used to hold the unit load smaller unit load may be desired

Unit Load (Cont) Seven steps to design a unit load Unit load concept applicable? Select the unit load type Identify most remote source of load Determine farthest practicable destination for load

Unit Load (Cont) Establish unit load size Determine unit load configuration Determine how to build unit load

Material Handling Device Types Conveyors Palletizers Pallet Lifting Devices Trucks Robots

Material Handling Device Types (Cont) AGVs Jibs, Cranes and Hoists Warehouse MHSs

Conveyors Accumulation Belt Bucket Can Chain

Conveyors (Cont) Chute Gravity Pneumatic or vacuum Power and free Roller

Conveyors (Cont) Screw Skid Slat Tow line Trolley Wheel

Trucks Hand truck Fork-lift truck Pallet truck Platform truck Counterbalanced truck Tractor-trailer truck AGV

Robots Point-to-point Contouring or continuous path Walkthrough or teach Lead through or teach pendant Hydraulic Servo-controlled

MHSs in Action Europe Combined Terminals (ECT) ECT - one of largest in world and largst in Europe Goods shipped from and to Europe Built on reclaimed land in the North Sea Large and Small containers

MHSs in Action (Cont) Trucks wait to be off-loaded by straddle carrier Carrier takes container to holding area Shipped in approximately 2 days Mobile gantry cranes on tracks deposit containers in forward area

MHSs in Action (Cont) Mobile gantry cranes hold containers in top four corners and deposit on waiting AGVs Fleet of AGVs in forward area take containers to tower cranes Tower cranes deposit load on ship bed Procedure reversed for off-loading ship

AGVs Classification of MHS Synchronous systems Asynchronous systems Synchronous systems, e.g. conveyors, used in continuous processes or heavy traffic, discrete parts environments

AGVs (Cont) Asynchronous systems, e.g., AGV, AS/RS, fork-lift trucks, monorails, cranes and hoists used in light traffic, discrete parts environments when material handling flexibility desired

Design and Control Problems in AGVSs Material flow network Location of pick-up/drop-off (P/D) points Number and type of AGVs AGV Assignments to material transfer requests AGV routing and dispatching

Design and Control Problems in AGVSs (Cont) Strategies for resolving route conflicts, so AGV throughput rate is maximized, an other costs (purchase, maintenance and operating costs of AGVs, computer control devices, and the material flow network, as well as inventory costs and production equipment idle costs incurred due to excessive material transfer and wait times), are minimized