The Lowly Tote

In my previous blog, I discussed Goods-To-Person (GTP) picking systems and how they can help solve the problem of Omni Channel Distribution for DC Managers. I don’t mean to hint that they are right for every application or that they are the only solution to fulfilling orders for multiple channels of distribution. GTP, like all material handling technologies, is just one tool in the integrator’s tool box of solutions.

I’d like to finish up on GTP systems in this blog by talking about the lowly tote. You know, plastic totes, or bins, or stackables. They go by many names and come in a lot of shapes and sizes. How do totes and GTP systems go together you ask? Very well, thank you. In fact they’re almost indispensable to a smooth running order fulfillment operation and should always be strongly considered. Most of the time when working with a client on the storage/retrieval element of their fulfillment system, I bring up the use of totes for storage and 99.9% of the time my client will roll their eyes and tell me they don’t use totes, just the carton. I’m sure they are doing the math in their head and trying to figure out how they can justify the expense to the boss. But as strange as it may sound, the lowly tote in automation might mean the difference between success and failure of the overall project.

I can think of several reasons why totes are your best option for storage and picking:

Uniformity

When we deploy any type of Automated Storage Retrieval System (ASRS), the load size is critical of course, but so is the integrity of the load. What I mean is that automated systems are very precise and repeatable, therefore the load being carried and stored is factored into the performance of the ASRS machine. If my carton size is 18 x 14 x 12 when I design the system and your vendor decides to change the carton size to 20 x 12 x 14 next year, we have a real problem. Maybe it won’t fit into the storage opening or the device designed to extract the load can’t handle that extra 2” of length. And cartons have flaps that pop up and cartons bulge and sag from humidity. Tape fails and cartons fall apart. Any idea what that does to a mini load or carousel or shuttle system? What I see most often is a variety (I mean mishmash) of carton sizes in distribution centers so the sizes range all over the place. This is very bad for an automated system. They require uniformity of load size. They run to their optimum level of performance with a uniform load. We reduce errors and maintenance when the product is safely tucked inside a standard size tote. With a tote we know what we’ve got every time. With cartons, every transaction is an adventure.

Productivity

Studies have shown that picking items from a tote is actually faster than picking from a corrugated carton. A picker knows what to expect every time the machine delivers the tote and that eliminates their hesitation because they don’t have to process a variety of carton arrangements. They don’t ever have to deal with flaps in the way. They won’t ever have to pull an empty carton out and throw it onto a trash conveyor. In fact I can eliminate the cost of trash conveyors in the system by having a central “detrash” station prior to replenishment. Dividers in totes can allow for pick multiple items for the order from the same tote and the GTP software directs them to the proper compartment within the tote. A QC check on the product can be done during the replenishment function, one less task for the picker to perform.  All of these little enhancements allow the picker to produce more picks per hour, and that reduces the overall cost of the operation. Add a few more picks per hour by a full day and multiply that by the number of people picking and we’ve generated quite a nice cost reduction that continues every day we use the system.

Conveyability

One of the jokes we like to tell in material handling is that all conveyors work great, until someone puts a load on it. That mishmash of carton sizes and construction plays havoc with conveyors, sorters, label applicators and scales. Conveyor is mechanization, a machine if you will. And machines love uniformity.

Eventually product has to be transported from the picking area to some other point in the DC. That may be a consolidation station or pack station or QC area. If I store in totes and pick to totes (or shipping cartons on trays) I can reliably and safely convey the product wherever it needs to go in the process. Most likely we can reduce the cost of a conveyance system if we have that uniform load in a rigid wall tote. And studies show that the cost to maintain a conveyor system is reduced if we eliminate the contamination from dirt, dust and pieces of corrugate.

Traceability

Collecting data during the fulfillment process is becoming more and more important, especially if the DC is delivering to multiple channels of sales. The use of totes makes this far easier and reliable than trying to keep track of various cartons in a system. Tote ID labels (license tags) tend to be more uniform when on a tote—we know exactly where the label is every time so scanning on the fly is faster and more reliable. RFID tags can be imbedded in a captive tote system which will dramatically increase the data collection capability of the fulfillment operation. We can manage inventory more accurately inside the GTP storage system with the use of uniform totes and this data can be uploaded to the Warehouse Management System (WMS) for reliable inventory counts. Product picked into totes and transported to packing or QC stations can be tracked more reliably as they move along a conveyor network or on carts. I think the word we want to remember is reliable. The use of totes in a fulfillment center can help us accumulate and use data more reliably than with cartons. As I said before, with a tote we know what we’ve got every time. With cartons, every transaction is an adventure. DC Managers like to avoid adventures.

I can think of more good reasons to use standardized totes in a fulfillment center but I think this is enough for today. Next time I’d like to start a conversation about voice directed systems so drop me a line to let me know how you already use voice systems, or how you might use voice direction in your facility. I’d love to hear from you.

Have a happy and safe holiday season and thank you for reading.

Michael