material handling systems to boost productivity

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1 WHITE PAPER www.intelligrated.com Working Smarter with What You Have In today’s credit-strapped economy, squeezing greater perormance out o existing inrastructure and equipment is a key DC management strategy. By optimizing the eciency and utility o buildings, equipment and systems that have already been paid or, companies can realize bottom line-enhancing productivity gains without major capital expenditures. Repurposing existing technology can also enable eciency gains and increases in capacity that allow older DCs to accommodate SKU growth, increases in store count, or adapt to changes in the order prole without major expansions or greeneld construction. Eciency improvements also make companies more nimble, giving them the fexibility they need to more rapidly adapt to ongoing market and business changes. Handling more throughput with existing “maxed out” systems The traditional response to dealing with the demands o growth has been to apply additional labor. Although this tactic can provide immediate incremental increases in a DC’s capacity, there is a limit to how eective it can be in the long term. Eventually, other constraints such as insucient sorter speed, or too ew pick aces or loading doors, will make additional increases to the labor orce an inadequate solution. At this point, the traditional “Plan B” was typically to purchase additional equipment, ex¬pand square ootage, or both. However, the current state o the global economy is causing the usual paradigm to change. Today, when labor increases are no longer the answer, and large capital expenditures are out o the question, it is time to examine the DC’s operation and identiy opportunities or reconguring material handling systems, adopting new sotware and/or altering processes to increase eciency and overall productivity. Productivity = Efciency x Utilization Productivity is a unction o both eciency and utilization. For example, the most ecient way to get product rom one side o the DC to the other is to cross-dock. The process o unloading goods at receiving and moving them across the building, directly onto another trailer is 100 percent ecient. But eciency is only one part o the productivity equation. Even though it is the most ecient process you can perorm, i you can cross-dock or only ve percent o the time, it is actually only ve percent productive (100% eciency x 5% utilization = 5% productivity). The goal o 100 percent productivity via cross-docking can be achieved only in a true “store per door” environment, in which there is a 1:1 ratio o stores serviced by the DC to actual ‘live’ shipping doors with constant availability (100% eciency x 100% utilization = 100% productivity). In the real world, ew companies have the resources required to ully implement such a system, but utilizing the principles o cross-docking in all other operations will increase productivity. It is important to note that these principles can be applied or order ulllment, manuacturing and shipping to achieve higher productivity and lower costs. While 100 percent productivity remains the goal, the rst step toward this ideal practice is a hybrid solution known as the two-stage cross-dock. Boost productivity o existing distribution systems with our cost-eective solutions By John Naylor, Intelligrated Whether your goal is to stay out in ront o business growth or to scale back operational costs to conserve capital in a shrinking economy, the good news or DCs is that eciency, productivity and capacity can oten be increased without a signicant investment in additional labor, foor space or equipment.

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Page 1: Material Handling Systems to Boost Productivity

8/6/2019 Material Handling Systems to Boost Productivity

http://slidepdf.com/reader/full/material-handling-systems-to-boost-productivity 1/5

1

WHITE PAPER

www.intelligrated.com

Working Smarter with What You Have

In today’s credit-strapped economy, squeezing greater perormance out o existing

inrastructure and equipment is a key DC management strategy. By optimizing the

eciency and utility o buildings, equipment and systems that have already been paid

or, companies can realize bottom line-enhancing productivity gains without major

capital expenditures.

Repurposing existing technology can also enable eciency gains and increases in

capacity that allow older DCs to accommodate SKU growth, increases in store count,

or adapt to changes in the order prole without major expansions or greeneld

construction. Eciency improvements also make companies more nimble, giving them

the fexibility they need to more rapidly adapt to ongoing market and business changes.

Handling more throughput with existing “maxed out” systems

The traditional response to dealing with the demands o growth has been to apply

additional labor. Although this tactic can provide immediate incremental increases in

a DC’s capacity, there is a limit to how eective it can be in the long term. Eventually,

other constraints such as insucient sorter speed, or too ew pick aces or loading doors,

will make additional increases to the labor orce an inadequate solution. At this point,

the traditional “Plan B” was typically to purchase additional equipment, ex¬pand square

ootage, or both.

However, the current state o the global economy is causing the usual paradigm to

change. Today, when labor increases are no longer the answer, and large capitalexpenditures are out o the question, it is time to examine the DC’s operation and

identiy opportunities or reconguring material handling systems, adopting new

sotware and/or altering processes to increase eciency and overall productivity.

Productivity = Efciency x Utilization

Productivity is a unction o both eciency and utilization. For example, the most

ecient way to get product rom one side o the DC to the other is to cross-dock. The

process o unloading goods at receiving and moving them across the building, directly

onto another trailer is 100 percent ecient. But eciency is only one part o the

productivity equation. Even though it is the most ecient process you can perorm,

i you can cross-dock or only ve percent o the time, it is actually only ve percent

productive (100% eciency x 5% utilization = 5% productivity).

The goal o 100 percent productivity via cross-docking can be achieved only in a true

“store per door” environment, in which there is a 1:1 ratio o stores serviced by the DC to

actual ‘live’ shipping doors with constant availability (100% eciency x 100% utilization

= 100% productivity). In the real world, ew companies have the resources required to

ully implement such a system, but utilizing the principles o cross-docking in all other

operations will increase productivity. It is important to note that these principles can be

applied or order ulllment, manuacturing and shipping to achieve higher productivity

and lower costs. While 100 percent productivity remains the goal, the rst step toward

this ideal practice is a hybrid solution known as the two-stage cross-dock.

Boost productivity o existing distribution systems with our

cost-eective solutionsBy John Naylor, Intelligrated 

Whether your goal is

to stay out in ront o

business growth or to

scale back operational

costs to conserve capital

in a shrinking economy,

the good news or

DCs is that eciency,

productivity and capacitycan oten be increased

without a signicant

investment in additional

labor, foor space or

equipment.

Page 2: Material Handling Systems to Boost Productivity

8/6/2019 Material Handling Systems to Boost Productivity

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WHITE PAPER

www.intelligrated.com

Solution #1: Two-Stage Cross-Dock to Cut Picking Labor in HalOutbound positions staged in waves reduce labor, rolling stock and space requirements

It is possible to markedly boost a DC’s order ulllment productivity by implementing

a two-stage cross-dock process that capitalizes on the eciency o the cross-dock,signicantly increasing utilization without large capital expense. The two-stage cross-

dock leverages existing assets to increase order ulllment eciency. When allocated

products, those that are already part o an existing order to be lled, arrive without

a corresponding outbound trailer waiting at a shipping door, additional outbound

positions are necessary. These are created by combining products into waves as they

are received. Waves are then staged in a buer consisting o a foor position, a pallet

position, AS/RS, or a trailer. When a shipping door becomes available, the waves that

comprise the order are pulled rom the staging area and loaded onto the appropriate

outbound trailer. This process can also be used or other operations; or example,

allocated ull cases destined or a split case order ulllment system can be staged by

wave and introduced into the tilt-tray, cross-belt or put-to-light system when the wave

becomes active. This eectively eliminates the putaway and discrete picking o cartons

by wave.

The two-stage cross-dock can reduce re-picking labor by more than 50 percent.

Although more labor intensive than a single-stage cross-dock, it is an attainable solution

that requires ewer shipping doors and uses signicantly less labor than the typical

material handling process (see Figure 1). The two-stage cross-dock example illustrated

in Figure 1 reduces rolling stock requirements by eight units and associated battery

requirements, and saves 127,000 additional square eet o foor space by eliminating the

need or a pick conveyor, a pick module and associated racking.

Figure 1 - Process and Rates Comparison

Current Process and Rates (3,280 per hour)

Projected Process and Rates (3,280 per hour)

ReceivingHand Palletizing

400 cph17 People

Storage36 Pal/HR6 People

Mod Replenishment36 Pal/HR6 People

Wave Sort/Load

600 chp11 People

Trailer Pull2 Person

Module Pick400 chp

17 People

Direct Unloads

800 cph8 People

Direct Unload900 cph8 People

Shipping

Receiving

Shipping

“...i you can cross-dock

or only ve percent o

the time, it is actually

only ve percent

productive.”

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Solution #2: Minimizing Product Gap to Increase Sorter ThroughputDecreased product spacing yields 40 percent increase

For many DCs, sorter throughput is a pinch point that negatively aects order

ulllment eciency. While modern sliding shoe sorters have reached the 600-650 t / min milestone in recent years, many existing sorter systems are limited to speeds equal

to or in some case signicantly less than this benchmark. The physics o the divert angle

limit these existing systems, making it impossible to speed up the sorter without a major

rebuild o the shipping system. Fortunately, speed is not the only parameter aecting

sorter throughput. By simply reducing the gap between cartons rom the traditional

12 inch average to our inches, sorter throughput can be increased by up to 40 percent.

Intelligent sotware, available rom suppliers o material handling systems, puts these

throughput increases within reach o DC operators without the need to invest in

additional capital equipment. In many cases, a 40 percent increase in throughput can

eliminate an entire shit o operations.

Solution #3: Balancing Merging or Maximum EfciencyReal-time balancing o induction lines by the merge can reduce gaps and eliminate fow 

 stops — producing a higher system yield.

Most distribution centers that operate within a ‘wave’ environment or have a strict

cuto time in a “store per door” setup suer rom a lack o balance in the operation.

It is natural or resources in various areas o picking, rom modules to cross-dock and

pallet strip lines, to operate at dierent rates rom each other and also vary individually

throughout the day. A contributing actor to imbalance is simple math in terms o the

workload. As a result o slotting, a pick module may be tasked with 50 percent more

case volume or a given wave than all other modules.

A typical induction system does not take into consideration the real-time wave

progression o the in-eed lines. Instead, it simply releases lines based on a simple set o

algorithms – round robin, “rst come rst served,” etc. The eect o this is elt towardthe end o the wave/batch. As areas are completed and the wave totes arrive at the

merge, the line is disabled until all lanes have successully completed. To provide some

temporary relie, some systems are equipped with wave overlap lanes; this does not

directly combat the issue, however. When the quantity o active lanes cannot sustain

the maximum capacity (100 percent eciency) o the sorter, it becomes a major drain

on productivity. The longer the system operates (utilization) in this state, the lower the

overall yield (productivity).

As an example: A sorter and an 8:1 merge have a total capacity o 200 cartons per

minute (cpm). Each induction line is capable o releasing 50 cpm and our lines are

needed to sustain 200 cpm. Due to imbalance, the last our lanes nish at varying times.

During the time that lanes 1 through 4 are completing, there are our lanes let and

the sorter is running at 100 percent eciency. Anything less is a major loss o systemeciency as shown below. As the duration increases, productivity is lost. With three

lanes x 50 cpm = 150 cpm (75% ecient) With two lanes x 50 cpm = 100 cpm (50%

ecient) With one lane x 50 cpm = 50 cpm (25% ecient) It is typical or a traditional

batching system to yield about 75 percent o mechanical capacity.

Traditional combiners, which “zipper” cartons at the merge point, produce relatively

larger gaps between product and are typically limited to a maximum o our incoming

lines. They are also more susceptible to productivity loss because o a lack o balanced

workloads.

“Due to slotting, a pickmodule may be tasked

with 50 percent more

case volume or a given

wave than all other

modules”

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Wedge merges are becoming an increasingly popular alternative to combiners as a result

o their ability to help maximize sorter utilization. With better batch fow control and up

to or over 16:1 merge capability, wedge merges oer more fexibility and less exposure

to productivity loss. Sotware and intelligent systems controls are available to enhance

these merge/induction setups and can make an existing DC more productive. By setting

the merge release logic priorities based on the orecasted volumes or each induction

line (case ootage in lieu o carton count is more precise), the system can better marshal

the workload through the system. To maintain better balance, unbalanced lines are

released based on percentage and real-time status and updates. Figure 2 illustrates the

dierent release times associated with an unbalanced ve-line merge o a 10,000 carton

wave.

Figure 2 - Wedge: Workload Balancing

Real-time progress should be measured through the merge while making “on the fy”

adjustments based on current wave status. Typically, there are higher-velocity picking

areas in a system: cross-dock vs. module. Although these areas have the same quantity

o cartons assigned or a wave, one may nish in hal o the time even with the same

quantity o resources applied due to the nature o the pick operation. It is not unusual

to see a higher-velocity pick area have more volume because o slotting o higher SKU

velocity movers. As they progress at dierent rates, each would require dierent merge

release priorities at dierent times in the wave. Converting or enabling the merge and

system controls and sotware to monitor progress allows or precisely balanced picking,providing much higher system yield (productivity).

Solution #4: Oset Wave Plan to Balance Loads and OptimizeStafng LevelsPredictability ensures that loads are completed within minutes o each other 

The stop/load model, a traditional retail door plan in which order waves are assembled

at a series o stops throughout the acility, allows DCs to load more store orders through

a limited number o doors. This method is highly sensitive to imbalance — a slowdown

Lane 1 - 20% of Release Time

Lane 2 - 10% of Release Time

Lane 3 - 20% of Release Time

Lane 4 - 20% of Release Time

Lane 5 - 30% of Release Time

Lane 1 - 2,000 Cartons Lane 4 - 2,000 Cartons

Lane 2 - 1,000 Cartons Lane 5 - 3,000 Cartons

Lane 3 - 2,000 Cartons

10,000 Carton Wave

Unbalanced Lines

Released by Percentage

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at a single pick module or shipping trailer can disrupt the entire fow and severely

reduce overall productivity by delaying wave completion. These unpredictable variances

in wave times and volumes inherent in the stop/load plan create gaps between waves

that reduce eciency. By shiting the wave paradigm slightly, an oset wave plan (seeFigure 3) improves upon the stop/load model by eliminating its unpredictability. The

oset wave plan not only increases the number o active doors compared to a standard

(odd – even) stop/load dock plan, but also removes the randomness that makes it

impossible to predict how many doors will be pulled. In a 44-door example, 40 doors are

active, o which our are being pulled at any one time. This model’s predictability makes

it easier to deploy optimum stang levels and provides better control over minimum/ 

maximum load per door per wave.

Figure 3 - Oset Wave Plan

Each section o every trailer gets an almost equal amount o product at the same time.

Although the oset wave plan may add a ew more waves to the day compared to the

stop/load model, balancing loads ensures that all loads are completed within just a ew

minutes o one another.

This wave plan eectively balances the entire shipping operation. The workload is

distributed across all doors and personnel evenly, allowing or predictable stang

levels and movement o resources. This helps to eliminate the scenario where shipping is

waiting or a small number o doors to be completed so that the merge can release the

next wave. This also ensures that the amount o doors active in a wave are great enough

to prevent overfow o product to re-circulation — imagine 200 cartons per minute

being distributed to our doors as a result o wave planning — and shutting down the

merge. See Solution 3 or examples illustrating the eect o merge ineciency. In either

event, the utilization o the system greatly suers. The oset wave plan ensures that the

merge and sorter are producing higher throughput or a greater percentage o the time.

Conclusion

By taking advantage o a good warehouse control system, good processes and your

existing space and equipment, you can increase productivity without great expense

while scaling back your operations to meet your changing needs. System integrators,

sotware providers or material handling equipment suppliers can help discuss which

options make the most sense or your operation.

For more inormation, contact Intelligrated by e-mail at [email protected] or by 

 phone at 866.936.7300, or visit www.Intelligrated.com.

Doors 41 to 44

Doors 1 to 4

Doors 5 to 8

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Doors 37 to 40

Waves 8 to 17

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Waves 27 to 36