Faced with constant pressure to fill orders quickly and accurately, distribution centers are turning to a dizzying array of technologies and strategies. One of the most popular is pick-to-light (PTL), which increases pickers’ ability to pick merchandise more quickly and accurately by means of lights positioned on the shelving or racking where products are kept. These lights signal pick locations and, in some cases, quantities to pickers.
PTL is a giant leap forward from the printed pick tickets that distribution centers have traditionally used. These paper tickets merely list the items needed to complete an order for shipping. The order picker, therefore, must spend a considerable amount of time reading the ticket, determining the optimal picking path, locating the necessary items in the warehouse, verifying that he has picked the right products in the right quantities, and fixing any mistakes. Even when the order is complete, the picker must note any variations, subtract the units picked for replenishment purposes, and either enter this information into a database or make sure that another employee dedicated to that purpose does so.
These multiple steps create an operational environment that is inefficient and highly prone to human error. PTL remedies this by combining the predictability and speed of automation with the intelligence of human labor. It is related to other semi-automated technologies such as radio-frequency (RF)-directed bar code scanners, “smart carts” (equipped with PTL, voice, or bar code devices), and voice-directed solutions (pickers wear headsets that tell them where and how much to pick and allow for verbal confirmation). In freeing pickers from reading paper tickets, these methods boost both speed and accuracy yet are not as expensive as fully automated technologies like the A-frame. This makes semi-automated picking technologies appropriate for operations that face capital budget constraints, as well as for slower-moving items that would not cost-justify the pricier complete automation.
PTL has been around for upward of two decades, but in recent years improvements to the technology, coupled with its increased affordability, have made it a popular choice among the various semi-automated picking methods. The technology is ideal for high-moving SKUs, according to Lance Reese, director of sales distribution technology at FKI Logistex, a maker of PTL and other technologies. An ideal pick-to-light environment is one where 20% of the facility’s SKUs account for 80% of its throughput, but there are seemingly myriad applications of and variations on the PTL concept.
Foxfire Technologies Corp., a supply chain information systems provider based in Six Mile, SC, is the maker of FoxFetch, a new light-directed pick-and-put system that does not use a server. Developed by Dr. Jack Peck, chairman of the company and a former professor and chair of computer science at Clemson University, it incorporates PTL, voice, and smart cart, and personal digital assistant (PDA) technologies into a single wireless system.
FoxFetch can interface with a warehouse management system (WMS). Its carts receive picking information from the WMS and are equipped with personal digital assistants (PDAs) that optimize the picker’s path to the pick location. When the picker arrives at the location, the PDA’s voice component speaks, “Stop.” The PDA activates the lights on the bay and the cart, signaling the quantities to pick and put. The picker can pick items from multiple locations for a single put area (box, tote, or other container) on the cart or pick multiple units of a single SKU for distribution to several different areas on the cart. The picker activates state-of-the-art proximity switches on the light modules on the shelving and the cart to confirm the pick and the put. If there is a shortage, the picker records it on the PDA.
When picking at a particular location is completed, the PDA says, “Move on,” and specifies the next location. The cart can transmit results to the host computer in real time or batch and send the results later. The system can be used for replenishment and includes management tools such as productivity tracking and layout of picking areas.
SEEING THE LIGHT
Material handling solutions manufacturer FKI Logistex, based in St. Louis, offers a PTL order fulfillment system called EASYpick, a suite of software and hardware products that can be integrated into a WMS. EASYpick has both pick and put applications and is appropriate for faster-moving SKUs. The software works with a system of lights visible from all locations within the picking zone and LED displays that show quantities.
The EASYpick system boasts a variety of management tools, including optimization of pickers’ walking patterns, batching of single-item orders, prioritizing of particular kinds of orders (for instance, refrigerated items), work distribution planning, monitoring of order completion, and productivity tracking. EASYpick can interface with radio frequency- and voice-directed systems, as well as with carousels and A-frames, in distribution environments that use both fully automated and semi-automated technologies.
For slower-moving items, EASYpick includes a component called the GoKart, a light-directed RF cart. A bay display on the cart tells the picker the location of the pick, the quantity, and the put location. The picker uses a handheld scanner on the cart for confirmation. The GoKart can handle up to 24 orders at a time.
PCC Systems, an automation and control systems supplier based in Germantown, WI, produces Lightning Pick, a light-directed pick-and-put system that incorporates radio frequency. Berny McCabe, the company’s sales manager, notes that the application is ideal for warehouses that handle high volumes of small orders and broken-case orders.
Lightning Pick consists of independent (without cables) light modules mounted on any kind of shelving or racking. Pickers use bar code scanners to scan labeled containers or totes on carts or conveyor belts. This activates the light module at the product location to be picked and signals the quantity to be picked as well. The picker presses a button on the light to confirm the pick and continues on to the next pick. Lightning Pick offers a variety of management tools and applications, including planning and real-time communications within the distribution center.
The system has worked particularly well for Current, a Colorado Springs, CO-based direct marketer of paper products, gifts, and home decorating items. In 2001 the company installed Lightning Pick’s LP Pick system in its 780,000-sq.-ft. distribution center, which allocates 120,000 sq. ft. to order fulfillment.
Before the PTL installation, Current picked an average of 300-400 cartons per hour and managed to bump up that number to 700 during peak periods. Three years later, the pick rate doubled, with the facility routinely averaging 1,400-plus cartons an hour during peak season. The percentage of picking errors plunged from 15.2% to 1.6%. Current is installing additional Lightning Pick lights in a facility expansion being built at the same location.
Karen Berman is a freelance writer based in Fairfield, CT.
This is the third installment of a three-part series on picking technologies and strategies. In this edition, we examine pick-to-light technology.
A Success Story
Chad Sullivan, director of distribution at Greensboro, NC-based Market America, has only good things to say about his company’s conversion from a paper picking system to pick-to-light technology.
Market America relies on a network of more than 100,000 independent distributors (much like Shaklee or Tupperware) in the U.S., Canada, and Australia. Among the company’s products are vitamins, cosmetics, automotive products, and cleaning products — more than 1,500 SKUs. Most distributors place their orders via Market America’s Website. “We call it the Mall Without Walls,” Sullivan says.
From the company’s founding in 1992 until 2000, it used a paper picking system. Then Market America installed PCC Systems’ Lightning Pick LP Pick. “At that time we had 128 staff,” says Sullivan. “Three-quarters were dedicated to picking orders. Now I have 69.” In the interim, Market America’s sales have grown by the double digits most years, but Sullivan says he has “not had to hire one employee in the distribution center.”
Before the Lightning Pick PTL technology installation, the distribution center routinely ran on two 10-hour shifts to pick up to 5,000 orders. Today, working with one 10-hour shift, the smaller picking crew picks up to 8,000 orders.
Sullivan credits all of this improvement in output to the Lightning Pick system. “We’ve more than doubled productivity, and we were saving somewhere in the neighborhood of $1.5 million in labor the last time I figured it out,” he says.
The pick-to-light system has also eliminated many of the staffing headaches common to distribution centers. Turnover has dropped to a mere 5%, and training new staff and getting them up to speed takes only three days as opposed to the month it took before Market America adopted pick-to-light. At the same time, picking accuracy has risen from 99.0% to 99.7%.
“Pick-to-light has made the whole process easier,” says Sullivan. “My employees tell me, ‘This is the easiest warehouse job I’ve ever had. There’s no stress.’”