Warehousing Equipment

1
Warehousing 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

2
The 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

3
The 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

4
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

5
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

6
Pallet Storage Modes

• Block Stacking
• Rack Storage
• Single-Deep
• Double-Deep
• Drive-In/Through
• Pallet Flow
• Unit Load AS/RS
• etc.

7
Block 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  withdrawn at one time.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

8
Selective 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

9
Double-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

10
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

11
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

12
Small 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

13
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.

14
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)

15
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

16
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

17
Warehouse docks and dock-related equipment

• Warehouse docks The facility interface with the
  shipping carriers
• Dock configurations and dimensioning

18
Equipment 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.

19
Automatic 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.

20
Automatic 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

21
Automatic Paperless Communication

• RF data terminal
• Voice headset
• Light and Computer Aids
• Smart card