Warehouse Equipment

7/31/2019 Warehouse Equipment

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Warehousing Equipment

Tompkins et al., Facilities Planning, John Wiley

& Sons, 1996: Chapters 6, 9

College-Industry Council on Material Handling

Education: Material Handling EquipmentTaxonomy: http://www.mhia.org/et/mhe_tax.htm


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The role of equipment in warehouseoperations

Reduce cost (labor + space) enhance space utilization by, e.g.,

enabling the exploitation of the vertical dimension of the facility

allowing for denser packing

allow for more efficient order-picking by, e.g.,

increasing the sku density supporting the automated transfer of material from storage to sorting

and consolidation area

Enhance responsiveness

increase the throughput of the facility, e.g.,

increasing the sku density establishing a more ergonomic environment/arrangement for the

warehouse operators

facilitating the parallelization of order picking

by parallelizing the tasks of order-picking and replensihment


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The role of equipment in warehouseoperations (cont.)

Maintain Quality of Product and Operations

provide an orderly storage environment

provide efficient ways for product tracing and identification

provide safe and secure material handling

facilitate order sortation and consolidation

establish and maintain a controlled environment e.g.,

temperature control

access control


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Equipment Classification

(Tompkins et. al., pgs 170-173) Containers & Unitizing Equipment

Storage and Retrieval Equipment

Unit Load

Small Load

Conveyors

Warehouse docks and dock-related equipment

Automatic Identification and Communication Equipment


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For detailed functional descriptions,discussion on supported efficiencies,

and pictures

College-Industry Council on Material Handling

Education: Material Handling Equipment

Taxonomy:http://www.mhia.org/et/mhe_tax.htm

Tompkins et al., Facilities Planning, John

Wiley & Sons, 1996: Chapters 6, 9
http://www.mhia.org/et/mhe_tax.htmhttp://www.mhia.org/et/mhe_tax.htm


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Pallet Storage Modes

Block Stacking

Rack Storage

Single-Deep

Double-Deep

Drive-In/Through

Pallet Flow

Unit Load AS/RS

etc.


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Block Stacking (or Floor Storage)

LanesLane Depth

(3-deep)

Lane Height

An efficient storage mode when

there are multiple pallets per SKU; inventory is turned in large increments, I.e., several loads of the same SKU

are received or withdrawn at one time.

Main problems:

Loss of space due to honeycombing not effective utilization of the vertical dimension of the facility


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Selective or Single-Deep or SimplePallet Rack

The benchmark storage mode

Due to rack supports, each pallet is independently

accessible (i.e. it supports totally random access)

Trade-off: too many aisles => inefficient space utilization


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Double-deep rack

Two selective racks placed back-to-back => 2-deep lanes

Each lane dedicated to one SKU => space loss in case of

SKUs with odd number of pallets

Less aisle space required (upto 50% savings in aisle space)

Trade-off: More work and/or specialized equipment forretrieving


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Other pallet rack types

Drive-In/Through rack: 5-10 loads deep Better space utilization

More difficult, even dangerous retrieval

Pallet flow rack: up to 8 pallets deep The rack shelves are slanted and have rollers, and therefore, every

time a pallet is retrieved from a lane, the pallet behind it takes its

position.

Allows for simultaneous picking and restocking

Supports FIFO operation

Typically used in high-throughput facilities

Cantilever rack:

Supports long items like timber and pipes


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Unit-Load Retrieval Equipment

Key Differentiation factors:

aisle width requirements

lift height/weight capacity

Lane depth they can reach

degree of automation

capital expense

Major types

Walkie Stacker

Counterbalance Lift Truck

Narrow Aisle Vehicles Automated Storage/Retrieval Machines


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Small Load Storage and RetrievalEquipment

Operator-to-Stock(or Man-to-Part or in-the-aisle) system:the operator travels to the storage location to retrieve

material

Stock-to-Operator (or Part-to-Man or end-of-aisle) system:

the material is mechanically transported to the operator forretrieval

Advantages of STO:

higher productivity

easier supervision better item security and protection

Disadvantages of STO:

more expensive

more maintenance

more difficult to reconfigure


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Operator-to-Stock Storage Equipment

Bin Shelving

Modular Storage Drawers in Cabinets

Carton Flow Racks

Mobile Storage

All the above equipment can also be arranged in

mezzanines to get a better exploitation of the building

cube.


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Operator-to-Stock Retrieval Equipment

Picking Cart

Order Picker Truck (for higher placed loads)

Person-aboard Automated Storage/Retrieval Machine

captive aisle

free roaming

(Robotic Retrieval)


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Stock-to-Operator Equipment

Carousels

Horizontal

Vertical

Independently Rotating Racks

Miniload Automated Storage and Retrieval Machine

Automatic Dispenser

Productivity gains Allow for extensive parallelization of order retrievals

Focus on extracting rather than traveling and searching


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Conveyors

(Flat) Belt

Roller

Telescoping Belt

Chute

Sorting

Deflector

Push Diverter

Pop-up Skewed Wheels

Pop-up Roller

Tilt tray

Remarks:

Conveyors change the economics of travel.

They can partition physically the warehouse into zones


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Warehouse docks and dock-relatedequipment

Warehouse docks: The facility interface with the shipping

carriers

Dock configurations and dimensioning


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Equipment facilitating the interfacingbetween docks and shipping carriers

Dock levelers: compensate the height difference betweenthe carrier platform and the dock door

mobile yard ramps

permanent adjustable dock boards

truck levelers

scissors-type lifting docks

Bumper pads: absorb the shock from the impact of the

shipping trailer with the dock walls (laminated rubber

cushions)

40,000 lb load traveling 4 mph => 150,000 lb force

Dock shelter: a flexible shield that when engaged to the

carrier provides a closed-environment interface between it

and the inner area of the warehouse

energy savings, increased safety, product protection, etc.


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Automatic Identification andCommunication Equipment

Permits real-time, nearly flawless data collection andcommunication, and therefore, it facilitates and increases

the real-time awareness of the location, amount, origin,

destination and schedule of the material.


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Automatic Identification andRecognition

Bar coding technology:

bar codes

bar code readers

bar code printers

Optical character recognition

Radio Frequency (RF) and Surface Accoustical Wave

(SAW) tags

Magnetic Stripes

Machine Vision


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Automatic Paperless Communication

RF data terminal Voice headset

Light and Computer Aids

Smart card

Documents

Warehouse Equipment