COMPETE

3 Tep Tips fer a Heaitiiy,Preductive Weri(piace

By taking an objective, quantitative look

at your warehouse or DC you'll find

ways to make a lasting difference in your

quality of work and life.

By Josh Kerst

Physical overexertion is the leading cause of the most seri-ous nonfatal injuries and illnesses involving days away fromwork, according to the Workplace Safety Index (Liberty Mu-

tual, 2008). Because warehouses and distribution center (DC) op-erations have an abundance of ergonomie challenges, and becausepeak order fulfillment periods tend to exacerbate these issues,warehouse workers are among the top three highest-risk occupa-tions for sprains, strains and low back disorders. These findingsmake a compelling business case for companies to systematicallyaddress the root causes of ergonomie issues in the workplace.

Most Common Injury Instigators>• Product storage heights that are too low or too high.Retrieving products from the floor, elevated shelving, inside

truck trailers, or from underneath storage racks increases a work-er's risk of overexertion due to torso bending/twisting and awk-ward upper extremity positions.

>• Poorly-designed packing and sorting workstations.Work benches and workstations often require extended reachesto access packaging material or products along conveyors. Theseworkstations often lack adjustability and require prolonged sit-ting or standing in awkward postures that increase ergonomierisk factors, such as back bending and extended reaches.

>• Poor flow management of goods through the warehouse.Lean principles are applied throughout most organizations butthey are not always seamlessly integrated with ergonomics. Ex-amples of this include using partial, double, or triple slotting stor-age techniques to maximize shelving space so that the greatestamount of product can fit in the smallest amount of warehousespace. This type of slotting can increase ergonomie risk factorssuch as bending and elevated reaches. In addition, workers maybend at the torso to reach under low racking, or they may be re-quired to forcefully pull out containers from under product stacksto access the appropriate item needed for order fulfillment.

>• Excessive walking while navigating narrow and con-gested aisles. Modern warehouses are larger than ever before andthe majority of workers' time is spent in travel. Narrow width andcongested aisles can add to this labor intensive activity, requiringorder pickers to stop farther from the designated pick slot andcarry items longer distances to pallets or carts. This can lead toemployees overloading themselves by carrying multiple parcelsaround obstacles to limit the number of trips.

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Fit Work to WorkerAs a practicing ergonomist who has spent a lot of time in this

tough environment, the common trends I have seen driving theincrease in ergonomie concerns are those listed above. However,these trends do not have to gain popularity. Adhering to oneergonomie principle can not only reduce injuries and illness inthe workplace but can lower workers' compensation costs andimprove worker morale and productivity.

The primary principle of ergonomics is to fit the job to thephysical and cognitive capabilities of the worker. Proper ergo-nomie applications in warehouse and DC environments cantranslate into a safer and more efficient workplace. Some ofthe factors influencing companies to consider ergonomie im-provements include the following:

>• The relentle.ss push to do more with less;>" Offering a higher number of stock keeping units (SKUs)

that may include vastly different product sizes and storagerequirements;

>- More consolidated DC networks (e.g., fewer buildings)using larger footprint (e.g., 1 million square feet) all-in-one fa-cilities that include single line orders, multiple line orders, unitloads, bulky non-conveyable orders, and individualized value-added services like gift wrapping;

>• Shifts in peak processing periods driven by an increase ine-commerce order fulfillment and through post-holiday redemp-tion of gift cards;

>• An increasing number of older workers, those aged 55years and older, in the workforce with a significant increase offemale employees between the ages of 65 and 74.

Simple changes can be implemented to assist even the mostcost-conscious and conventional organizations that have mini-mal plans for expansion.

Three Top Tips1. Improve Storage and Product AccessAn ergonomie principle frequently shared with warehouse

employees is the adage, "If you cannot shake hands with yourwork, it is unfriendly." The best method to keep warehouse workuser-friendly is to position SKU access to high frequency itemsinside the "handshake zone" (heights from 37" to 47", within16" from your body). Here are some of the current best practicesfor keeping warehouse work friendly and efficient:

>• Use single slotting for the most frequently handled itemsand optimize access within the comfort zone (24" to 62" workheights) and ideally in the handshake zone.

>• Ensure that employees have access to at least three sidesof a pallet, if feasible. Emphasize this point with fork lift driverswho move pallets in and out of slots. Pallets that are too close inproximity may not give employees enough clearance to easilyreach the items at the rear. Therefore, extended reach postures,or stepping onto or around pallets, to retrieve product is neces-sary. This method increases the likelihood of potential slip/tripand fall injuries.

>• Train employees to use pyramid de-palletizing techniquesrather than layer picking to minimize extended reaching.

> Use drawer-style racks or pallet dollies to slide the bottomrows of pallets out to bring work closer to the employee.

>• Raise work heights through methods such as raised bottomshelving, adding sacrificial pallets under loads, or raising theforks on powered industrial trucks to improve load access.

>• Use gravity-fed flow racks to reduce the space consumedfor slower moving products.

>• Use load leveling carts and rolling canvas totes with springbottoms to keep loads at handshake height.

>• Consider high lift (>30") pallet jacks to be used as portablelift tables.

>• Use low-profile pallet turntables for high volume pick ar-eas; scissor lifts are most useful and typically cost-justified forthe highest-moving products.

>• Consider lighter weight plastic pallets and use a pallet dis-penser to limit manual handling.

2. Provide Ergonomie Warehouse Workstations>- Today's packing or order processing workstation or work-

bench is frequently intertwined with the overall warehouse sys-tem, and the equipment, materials, and supplies storage need tocoincide with the flow of the work.

> Provide adjustable height stations to accommodate differ-ent sizes of operators. Be sure to provide preferred referencemarks for employees to easily and consistently position tables.

>• Store knock down flat product supplies vertically, like li-brary books, instead of flat, like folded laundry.

>• Mount peripherals such as keyboards, HMI screens, tap-ing, or packing material on adjustable arms to unclutter theworksurface.

> Use box edge flaps to improve access and reduce awkwardupper extremity positions.

>• Use tilt stands to improve loading access.>• Provide anti-fatigue matting and foot rails for standing op-

erations to reduce static loading.>• Use LED lighting to improve the visual environment.>• Use conveyor-mounted deflect bars to move product close

to the side edges to reduce reaching.3. Optimize warehouse layout and order picking equipment>• Integrate ergonomics with warehouse management sys-

tems (WMS) so that optimal slotting can be done based on con-tainer characteristics such as weight, size, and throughput. Ad-ditional recommendations include the following:

>• Review the wai'ehouse and DC slot-management system tooptimize the flow of goods through the warehouse and to ensurethat pallets are placed in full slots according to case weight andmovement speed of the product.

>• Increase the width of aisles where fast-moving product islocated. This will allow pallet jacks to get closer and will reducethe distance the loads must be earned.

>• Stagger the start times for employees at the begirming of

w w w . m h l n e w s . c o m | J A N U A R Y 2 0 1 3 | MATERIAL HANDLING & LOGISTICS | 4 5

COMPETE

the day so that fewer workers access the same slots at the sametime. Small start time differentials can provide adequate spacingfor sufficient disbursal during order picking.

>• Use a preventive maintenance program for existing palletjacks and carts. This requires periodically checking the workingcomponents of all pallet jacks and carts so they are kept in goodcondition and within the push and pull requirements.

>• Consider vertical carousel lifts or systems that use the"goods-to-person" principle to eliminate walking times.

> Provide intelligent assist devices; these computer con-trolled devices enable employees to lift, move, and positionloads more quickly and intuitively.

>• Build in ergonomie criteria, such as rotating and vibrationreducing seats and high visibility masts, into the purchase orlease specifications for powered industrial trucks.

The Future Warehouse and DCTechnology and different warehouse layout options are mak-

ing it easier for companies to design their space to overcomeergonomie challenges. WMS improvements, such as pick-to-light, pick-to-voice, or even pick-to-feel systems, can minimize

walking distances, reduce errors, and reduce multiple handling.Also consider alternative warehouse floor plan designs, de-

pending on the prod-uct and deliverymethods. Innovativelayouts, such as theFlying V, Fishbone,or Chevron, reducedual-command travel Chevron Layoutby almost 10%, whencompared to a traditional warehouse with a middle cross aisle,and by up to 15.5% when compared to a traditional warehousewithout a middle aisle (Gue and Meiler, 2008).

These are just a few potential ergonomie improvements forwarehouse/distribution centers. When you take an objective,quantitative look at this environment, you will see that there areopportunities, and that you can indeed make a difference. MH&L

¡osh Kerst, CPE, CIE, is an ergonomist and vice president with

Humantech, Inc. (www.humantech.com), an ergonomics con-

sulting firm in Ann Arbor, Michigan.

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