ORDER PICKING IS THE HIGHEST PRIORITY IN A WAREHOUSE FOR PRODUCTIVITY IMPROVEMENTS

It’s the most costly activity (63% of operating costs) because:

• Labor intensive• Material & information system intensive• Decision support system and engineering projects

intensive• Many error occur in order picking

It’s increasingly difficult to manage because of new operating system programs

Chapter 8Order Picking Operations

NEW OPERATING SYSTEMS INCLUDE:

• JIT• CT reduction (cycle time)• QR (quick response• Micro-marketing strategies• Mega-brand strategies

•THESE REQUIRE:

• 1. smaller orders delivered more frequently & more accurately

• 2. more SKUs in system requires dramatic increase in throughput, storage, and accuracy

• 3. renewed focus on quality improvements & customer focus

Chapter 8Order Picking Operations

HIRING MORE PEOPLE (THE TRADITIONAL APPROACH) OR INVESTING IN MORE AUTOMATION HAVE BEEN STYMIED

Due to: • labor shortages & • high hurdle rates due to uncertain business

environment•Some strategies include:

• Issue pack optimization• Pick-from-storage• Pick task simplification• Order batching• Slotting optimization• Pick sequencing

Chapter 8Order Picking Operations

ISSUE PACK OPTIMIZATION:

• Encourage full or half pallet orders• Reduces counting• Reduces physical handling• Reduces extra packaging

• Requires balancing between holding and handling costs

Chapter 8Order Picking Operations

PICK FROM STORAGEGOAL IS TO PICK FROM RESERVE STORAGE AREAS – NO

FORWARD PICKING AREAS ARE REQUIRED

Example: Ford Service Parts Distribution Centers:• Automated – receipts arrive by rail in wire basket with

ID plate• Operator scans into WMS • WMS directs operator to distribute content into totes

(each with ID)• Totes assigned to & conveyed to one of 54 horizontal

carousels for putaway• WMS interleaves putaway & picking activities• Picking is light-directed – and order totes are light

directed

Chapter 8Order Picking Operations

THE CAROUSELS ARE THE RESERVE STORAGE-REQUIRES A HIGHLY SOPHISTICATED SYSTEM

• Uses random storage• Intelligent slotting• Activity balancing• Dynamic wave planning• High mechanization• Disciplined work force• Moves storage location to the picker

Chapter 8Order Picking Operations

PICK TASK SIMPLIFICATION:

• Eliminate / combine tasks when possible• Human elements involved in picking:

• 55% - traveling to, from, between pick locations• 10% - extracting material from locations• 20% - reaching/bending, documenting, sorting,

packing• 15% - searching for location

• Can be reduced through several approaches (next slide)

Chapter 8Order Picking Operations

STOCK-TO-PICKER:

• Reduce travel time• Carousels• Mini-loaders

• Design of system critical to minimize wait time

PERSON-ABOARD SYSTEMS AUTOMATICALLY GO TO PICK LOCATIONS

• Frees picker to document, sort, pack while machine is moving

Chapter 8Order Picking Operations

PICKING/SORTING/PACKING

More than one order at a timeUse carts with totes / dividersPick & pack simultaneouslyWorks well when order cube is small

Packing/shipping containers must be set-up ahead of time and placed on picking carts equipped with totes or dividers

Chapter 8Order Picking Operations

Chapter 8Order Picking Operations

Work Element Method of Elimination

Required Technology / Functionality

Traveling Bring pick locations to picker

STP System: Miniload ASRS Horizontal Carousels Vertical Carousels

Documenting Automate information flow

Computer-aided order picking: Automatic ID System Light-aided order picking RF Terminals Headsets

Reaching Present items at waist level

Vertical CarouselsPerson-aboard ASRSMiniload ASRS

Searching Bring pick locations to picker

STP SystemsPerson-aboard ASRSMiniload ASRS

Chapter 8Order Picking Operations

Work Element Method of Elimination

Required Technology / Functionality

Extracting Automated Dispensing Automatic Item PickerRobotic order picker

Counting Weigh countingPrepackage in issue quantities

Scales on picking vehicles

Restocking Automated look-ahead replenishment should ensure each location has sufficient pick-quantity before the picker reaches the location

Location min-max triggers

Excessive socializing Assign operators dedicated zones for picking and put-away

Idling / waiting for work Dynamic zone sizingPerpetual to-do list

Real-time WMS

ADVANTAGE OF SINGLE ORDER PICKING IS ORDER INTEGRITYDISADVANTAGE IS PICKER TRAVELERS GREATER DISTANCES

ORDER BATCHING (TO REDUCE TRAVEL TIME/LINE ITEM) More orders picked by a picker during a picking tour Especially effective for small orders (one to five line items) Batch small orders by picking zone

ZONE PICKING REQUIRES DOWNSTREAM SORTATION Pickers are assigned to a specific area, portion of an aisle,

multiple aisles, carousels, etc… (zones)

Chapter 8Order Picking Operations

STORAGE ZONES ARE DISTINGUISHED FROM PICKING ZONES

Designed for save, efficient storage Ie; bulky items, floor storage, small items, bar

stock, refrigerated, frozen, flammable, explosive, etc…

FREE-FORM PICKING IS THE OPPOSITE OF ZONE PICKING

Pickers responsible for picking every item in the order.

Move throughout the warehouse

Chapter 8Order Picking Operations

BENEFITS OF ZONE PICKING Reduced travel time Minimal congestion Product-location familiarity Operator-zone accountability

MAY OR MAY NOT PAY FOR ITSELF (INCREASED CONTROL COMPLEXITIES)

Order assembly requirements across zones (pass from zone to zone or wave picking with down-stream sortation)

Imbalances in workload, bottlenecks, gridlock, low morale

Chapter 8Order Picking Operations

COTTER & CO – LOGISTICS SUBSIDIARY OF TRUE VALUE HARDWARE Has conveyer down center of each zone Picker has roll of pick labels sorted in location

sequence Enables picker to make one pass thru zone during

a pick wave Picker pulls item, put barcode on it, puts it on the

conveyer and moves to the next location Conveyor transports to downstream sortation Metrics are posted at the end of each zone –

productivity, pick accuracy, and housekeeping

Chapter 8Order Picking Operations

PROGRESSIVE ORDER ASSEMBLY (PICK AND PASS)

Order passed from one zone to next until order is picked

Uses totes, pan, conveyor, carton, etc. Moves on conveyor or manually on a cart, or

pallets on a towline conveyor, AGV, lift truck, pallet jack

INTELLIGENT PROGRESSIVE ORDER ASSEMBLY SYSTEMS

Only move containers to a zone if there is a SKU for that order in that particular zone (called zone-skipping)

Chapter 8Order Picking Operations

DOWNSTREAM SORTATION

No order designation during picking Pickers make pass thru zone during pick wave Items bar-code labeled when picked Placed in cart or on conveyor Picked items go to sorting system where they are

placed into ordersSORTATION SYSTEMS RUN INTO THE MILLIONS OF DOLLARS

Benefits need to out weigh the cost

Chapter 8Order Picking Operations

SLOT OPTIMIZATION:

SLOTTING IS DETERMINING–

Appropriate storage mode Appropriate allocation of space within its storage

mode Appropriate storage location within its storage

mode

Chapter 8Order Picking Operations

SLOTTING HAS SIGNIFICANT IMPACT ON WAREHOUSE KEY PERFORMANCE INDICATORS:

Productivity Shipping accuracy Inventory accuracy Dock-to-stock time Warehouse order cycle time Storage density Level of automation

Chapter 8Order Picking Operations

SLOTTING GENERALLY HAS MORE INFLUENCE ON OVERALL WAREHOUSE PERFORMANCE THAN OTHER ASPECTS OF WAREHOUSE MANAGEMENT

MOST WAREHOUSES ARE IMPROPERLY SLOTTED:

Due to lack of dataMIS resourcesNo way to keep slotting currentNo methodology for slotting

Chapter 8Order Picking Operations

TEN STEP METHOD FOR SLOTTING:

1) Perform whse performance & whse gap analysis a) See how slotting could improve the operationsb) Won’t work if…

i. Poor managementii. Poor moraleiii. Undisciplined workforceiv. Union-management tensionv. Poor housekeepingvi. Inadequate computer training/support

Chapter 8Order Picking Operations

Chapter 8Order Picking Operations

TEN STEP METHOD FOR SLOTTING:

2) Populate slotting databasea) Describing activity, dimensions, storage

characteristicsb) Include:

i. Item Numberii. descriptioniii. Material typeiv. Storage environment (frozen, flammable, etc)v. Shelf lifevi. Dimensions, cube, weightvii. Units/carton – cartons/palletviii. Unit of Measure

Chapter 8Order Picking Operations

TEN STEP METHOD FOR SLOTTING:

3) Compute slotting statisticsa) Popularity (# times hit) (P)b) Turn-over (T)c) Unit Cube (C)d) Unit velocity (V = TC)e) Pick density (D = P/V)f) Demand Increment (I = T/P)g) Standard Deviation of Demand (S)h) Slotting Period (R) - (years, months, etc)

Chapter 8Order Picking Operations

TEN STEP METHOD FOR SLOTTING:

4) Conduct Warehouse Activity Profile (Ch 2) – include:a) Picking mode profileb) Operations Planning Profile

5) Assign items to familiesa) Storage environment family b) Order completion zones, within environment

family, based on order completions and demand correlation profile

c) Item activity profile, within order completion zones.

Chapter 8Order Picking Operations

TEN STEP METHOD FOR SLOTTING:

6) Assign Item Activity Families to Storage Mode Families – based on least cost storage mode option for each item

7) Map individual warehouse locations within each storage mode into Picking Activity Zones.a) Plot Pick Path

i. Serpentineii. Main line with side tripsiii. Pod of 2 or 3 carousels

Chapter 8Order Picking Operations

TEN STEP METHOD FOR SLOTTING:

8) According to Pick Density assign items to Storage Mode Activity ZonesBegin with highest density in A locations, then B

locations, then C

9) Specify Re-slotting Rules Rules for when or if an item should be re-slottedUse From-To chart to compute cost savings by moving

from a zone to every other zone

Chapter 8Order Picking Operations

TEN STEP METHOD FOR SLOTTING:

10) Pick sequencinga) Sequence pick locations visits to reduce travel time