Title: Warehousing Equipment
1Warehousing Equipment
- Tompkins et al., Facilities Planning, John
Wiley Sons, 1996 Chapters 6, 9 - College-Industry Council on Material Handling
Education Material Handling Equipment Taxonomy
http//www.mhia.org/et/mhe_tax.htm
2The role of equipment in warehouse operations
- 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/arrangem
ent for the warehouse operators - facilitating the parallelization of order picking
- by parallelizing the tasks of order-picking and
replensihment
3The role of equipment in warehouse operations
(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
4Equipment 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
5For 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
6Pallet Storage Modes
- Block Stacking
- Rack Storage
- Single-Deep
- Double-Deep
- Drive-In/Through
- Pallet Flow
- Unit Load AS/RS
- etc.
7Block Stacking (or Floor Storage)
Lane Height
Lane Depth (3-deep)
Lanes
- 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withdrawn at one time.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
8Selective or Single-Deep or Simple Pallet 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 gt inefficient space
utilization
9Double-deep rack
- Two selective racks placed back-to-back gt 2-deep
lanes - Each lane dedicated to one SKU gt 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
for retrieving
10Other 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
11Unit-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
12Small Load Storage and Retrieval Equipment
- 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 for
retrieval - Advantages of STO
- higher productivity
- easier supervision
- better item security and protection
- Disadvantages of STO
- more expensive
- more maintenance
- more difficult to reconfigure
13Operator-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.
14Operator-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)
15Stock-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
16Conveyors
- (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
17Warehouse docks and dock-related equipment
- Warehouse docks The facility interface with the
shipping carriers - Dock configurations and dimensioning
18Equipment facilitating the interfacing between
docks and shipping carriers
- Dock levelers compensate the height difference
between the 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 gt 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.
19Automatic Identification and Communication
Equipment
- Permits real-time, nearly flawless data
collection and communication, and therefore, it
facilitates and increases the real-time awareness
of the location, amount, origin, destination and
schedule of the material.
20Automatic Identification and Recognition
- 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
21Automatic Paperless Communication
- RF data terminal
- Voice headset
- Light and Computer Aids
- Smart card