When should you cube and weigh?

In today's high-velocity distribution centers, there's no room for guesswork. That's particularly true when it comes to the size and weight of products stored and handled at the site. Having accurate weight and dimensional data can help you calculate outbound shipping costs correctly, determine your exact storage and material handling system needs, and catch mispicked orders before they go out the door.

But where and when should you gather cube and weight data? Most people would say it should be done at an outbound packing station just prior to shipment. While there's much to be said for that approach, it's not the only answer. There are good arguments for cubing and weighing at other times and places in the DC. Here are four recommendations from those in the know:

1. During a one-time inventory audit. Data on the exact size and weight of every product you handle can be helpful in optimizing your material handling and storage systems and for choosing the best picking mechanism for those products. But not all companies have that information at their fingertips, says Bob Babel of the systems integrator Forte.

"In particular, small and medium-sized companies usually don't have good, accurate sizing information of products that move through their material handling system," Babel says.

If that's the case in your operation, a size and weight audit of active inventory might be in order. Babel notes that this could be as simple as renting or buying a static dimensioning system and setting it up near receiving. As items arrive, they can be placed on the dimensioning system, which will automatically capture their height, length, width, and weight.

Another option would be to take a static dimensioning system and place it on a cart with a battery, says Jerry Stoll, service market manager for Mettler-Toledo Inc., a manufacturer of cubing and weighing products. Workers can then can simply wheel the cart around to the various storage and picking locations to capture the relevant data.

2. At receiving. A one-time inventory audit probably won't be sufficient for DCs whose product mix—or product packaging—changes frequently. These operations will likely need to make cubing and weighing a routine part of their operations.

But where's the best place to carry out these activities? Clark Skeen, president of Quantronix, the maker of the Cubiscan line of cubing and weighing equipment, has some ideas on the subject. He strongly urges DCs to consider making it part of the receiving process. "The ideal time and place to collect cubing and weighing data is at the point of receipt," he says.

If you only gather cube and weight data at an outbound shipping station, you'll miss out on at least 50 percent of the benefits that the data can provide, Skeen says. That's because a product's cube and weight can and should influence decisions about slotting, storage location for putaway and picking, and repacking and containerization for shipping. "If you collect that data at the point of receipt, then it's available for each and every one of those decision points," he says.

Indeed, some facilities may choose to collect cube and weight data only at receipt, Stoll says. Those that do typically are simply storing and distributing product and are not repackaging or altering it in any way, so they know the dimensional data will not change, he explains.

To gather this information during receiving, many companies use automated dimensioning systems. For instance, high-volume operations that use conveyors to unload trucks might use an in-motion dimensioner attached to the conveyor. This approach has the advantage of allowing companies to check 100 percent of the products moving off the truck and obtain up-to-the-minute data on them, says Dan Hanrahan, president of the Numina Group, which supplies inline-scan weight dimensioning solutions. "That way, the warehouse management system and transportation system are always working from real-time data, so the information is being audited [during] the upfront process, and you can make changes to your system in real time," he explains.

3. After putaway or picking. Collecting dimensional data at receiving might not always be practical. For example, on a big receiving day, you may not have the time or floor space to perform cubing and weighing activities. In that case, an alternative might be to weigh and measure items after putaway (which can be accomplished by means of a mobile cart) or as they move from picking to shipping.

There are a number of potential benefits to this approach, experts say. For one thing, dimensioning systems can help with quality control after picking, according to Hanrahan. If a picker selects the wrong item or quantity, the order's weight will likely vary from the expected weight. And a damaged carton's dimensions may not conform with those of an undamaged box. An inline system located on a conveyor belt between picking and shipping will detect these deviations immediately and divert the order to an inspection station, says Hanrahan.

An alternative to a conveyor belt system is to use lift trucks with scales incorporated into their forks, says Stoll. He notes that this approach is popular with operations that place a premium on speed. "That [alternative] is mostly used by companies that have multiple forklifts that are moving a lot of freight fast, so they're worried about time constraints," he says.

4. Right before shipping. Perhaps the most common application of cubing and weighing systems is to collect data on parcels immediately prior to shipping. After all, that information is essential to determining the correct shipping costs.

To get the most accurate reading for this purpose, it's best to measure the dimensional weight of the box after it's been sealed and labeled. This is particularly important when shipping via parcel carriers that charge based on dimensional weight. By gathering precise dimensional data on their packages, shippers can ensure they're rating their parcels correctly and avoid chargebacks or overcharges by carriers. It is also important for less-than-truckload (LTL) shipments because carriers often "ballpark" weights to determine shipping costs, says Derek Jones, senior marketing product manager for Lantech, which recently began offering a scale option for its stretch wrappers.

Even companies with private fleets that don't have to calculate parcel shipping rates can benefit from cubing and weighing at the time outbound shipments are prepared, Stoll says. Accurate weight and dimensional information can help them make optimal use of the available truck space.

Substantial payback
To be sure, it's possible to get dimensional weight information without using a cubing and weighing system. For example, companies can get the data straight from the supplier, or they can manually measure and weigh the products. They also have the option of using cube calculation or "cartonization" logic based on the dimensional data in a WMS. But those results are not guaranteed to be accurate. According to Hanrahan, 5 to 10 percent of the time, packers use a smaller or larger box than expected.

In the end, what matters is not so much how or where you collect cubing and weight data, but that you do it, says Skeen of Quantronix. The information you collect will have great value, he says. And the more you use it, the more that value grows. Accurate, up-to-date cubing and weighing data offers a substantial payback for a relatively small investment, he says. "The information it provides is absolutely essential if you want to be a world-class distribution center."

Editor's note: For more on this topic, see "10 ways to boost DC performance with cubing and weighing systems."