"A place for everything and everything in its place” is a philosophy nowhere more applicable than when you’re overseeing a multi-million dollar distribution center (DC). A DC lives and dies on knowing when and where everything is received, stored and shipped out.
Tracking the “history” of a single carton sitting in its storage location is difficult enough. Keeping track of it at speeds of up to 600 feet per minute is a totally different challenge. That’s precisely when a company needs to determine if a sortation system is justified, and if so, which sortation system is right for its operation.
A sortation system (sorter) is an integrated material handling conveyor system that automatically diverts product to a conveyor or chute for delivery to other areas of the DC, including put-away, consolidation, replenishment, picking, audit and outbound shipments. A sorter usually is chosen when the required speed and accuracy of an operation are too great to compensate for with manual labor.
An example would be a DC that receives truckloads of unsorted boxes of running shoes and sorts them onto pallets by style, size, width and color. Unfortunately, every size comes in shoeboxes that look exactly like every other shoebox, except for the bar code label. Needless to say, it would be a nightmare scenario to manually sort and palletize several thousand boxes of shoes. However, a sortation system can identify and sort based on the desired characteristic to a specific location so they can eventually be consolidated onto a pallet for further processing or storage.
Obviously, this solution requires that the DC receives and ships a large enough quantity of shoes to justify a sufficient payback timeline or ROI. When calculating ROI, one must consider such factors as the cost of land, labor, inventory and taxes to justify an automated sortation solution. So where does one begin?
NARROWING DOWN THE OPTIONS
Choosing the right sorter depends on several factors. To assure accuracy, a significant amount of time should be invested in understanding the entire process and interviewing all work cells and levels of operation. These questions will typically help narrow the options for a shipping sorter:
1. What are the goals? Specify the needs among speed, accuracy, reducing human touches, freeing up floor space, process changes, building expansion, etc.
2. What are the product characteristics (dimensions, weights and types)? Cartons smaller than 6 inches wide by 9 inches long by 1 inch tall in any dimension will affect the choice of conveyor and sorter technology. Plastic bags or unusual pallet types will also limit technology selection.
3. Is the product trucked by pallet load, individual cartons or some other way?
4. Will cartons be shrink-wrapped or have other reflective properties? This adds complexity to the system’s equipment selection such as scanners and photo eyes.
5. Does each individual carton have a readable (via inline scanner) bar code and where is the bar code located on the product?
6. What is the average weight and the maximum weight of the product? This will affect equipment selection and/or drive size requirements.
7. How many cartons will be conveyed and sorted in a specific amount of time? Simple math provides the average throughput rate required for the system.
8. What is the system’s expected peak rate? In most cases, an operation will have busier times of day than others, and so a system will need to, whenever feasible, be designed for the required peak rate.
9. If it is a shipping sortation system, how many dock doors will the sorter feed? Can this number of doors accept the volume of product being delivered by the sorter?
10. What is the anticipated growth of operations? Typically, a sorter should be designed to accommodate at least three years of future business growth. Additionally, one should also have a strategy for sortation system modifications to support long-term (five to 10 years) growth.