Order picking cannot be an afterthought
Follow industry veteran John Hill's five steps and figure out which type of picking will work best for your facility.
By John M. Hill, vice president, TranSystems -- Modern Materials Handling, 9/17/2008
Order picking is at the very heart of warehouse operations. It generally consumes the most time (as much as 80% of total warehouse hours when coupled with travel and search times), costs the most money (55% or more of the typical warehouse budget) and holds the greatest potential for cementing or unraveling customer relationships.
Accordingly, it’s not surprising that so much effort has been spent on analysis and development of methods and technology aimed at fine-tuning and enhancing the integrity of the order-picking function—particularly case and mixed-case item picking.
The question, of course, is which of the myriad options or combination of options is best for your particular requirements:
single order picking,batch picking,pick and pass,bucket brigade, orcluster picking
Uncovering the answer is a five-step process.
Step 1. Although warehousing lore suggests the hour and cost impact of picking on typical operations suggested above, what are your actual costs in terms of operator hours, infrastructure and support? What are your costs per order? How long does it take from order release to shipment? How about error rates? Can you place a dollar value on a 5 to 20% improvement in any or all of these areas? You should!
Step 2. Next, what do your orders look like? Have you profiled them by number of SKUs, quantities, weights, cube and pick frequency? Does your warehouse layout and inventory slotting match the profiles and order volumes to reduce “touch” and minimize travel times? Are your storage media configured and sized for easy accessibility and simplified pick task execution? Are your forward pick areas close to the shipping docks? Do your order volumes and product dimensions warrant a closer look at automated dispensing systems or A-Frames? In a nutshell, profiling is fundamental to making solid decisions on:
Pick zoning strategies and space requirements
Product storage mode assignments and slotting
Forward pick area options
SKU pick face sizing
Pick face sequencing alternatives
Replenishment quantity determination and scheduling
Pick method alternatives
Step 3. When was the last time you mapped your picking process flows? Putting together step-by-step descriptions of the tasks to be performed by operators often reveals issues, bottlenecks and opportunities for shortcuts that can lead to improved performance. Once the mapping is completed, get your operators involved in alternative assessment! Not only are they more familiar with the challenges, their engagement in identifying opportunities will go a long way in building their ownership of the modifications you implement.
|
Typical Issues |
Possible Solutions |
Travel between locations |
Bring locations to operator – carousels, AS/RS, mini-loads |
Travel time |
Above, cluster pick with carts, batch pick with sortation |
Location searching |
Use pick-to-light displays, bar code &/or voice with WMS |
Pick tour set-up |
Sequence via WMS |
Pick confirmation (accuracy) |
Bar code, RFID and/or voice |
Counting |
Prepackage or weigh |
Emergency replenishment |
Use WMS to monitor pick location quantities |
Congestion |
Spread fast movers across multiple pick faces |
Step 4. Next, what tools do your operators use to simplify pick task execution? Are you paper-based or do you use bar coding? If the latter, have you looked at voice technology as a hands-free alternative or even RFID? Are you using a WMS to sequence order picking tours based upon your rules, while monitoring throughput and providing status visibility in real time? Have you looked at multi-modal data capture technology that, for example, permits a user to select bar code for a given picking task without precluding the use of voice or RFID for others in the same facility?
Step 5. Finally, with answers to the foregoing questions in hand, you’ll be able to assess the merits of alternative picking methods in terms of the incremental investment required to achieve improved performance. And, as many of you know, you may very well wind up with a hybrid.
Resources
Resources on order picking abound—from academia to warehouse designers and consultants to solution suppliers. Of particular note are materials available from the College Industry Council on Material Handling Education and OFC, MHIA’s Order Fulfillment Council, whose eLesson series on order picking is a good basic primer.
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