The process of picking, packing, and shipping an order consists of a series of steps that occur in a defined sequence. Whether that process is completed correctly and on time depends on how well each step is carried out. When automation is involved, an additional factor comes into play: Success also depends on how well the various pieces of equipment used in the process are integrated with each other. In the case of an automated packaging line, that means getting each of the machines—carton erectors, shrink wrappers, void fillers, labelers, document inserters, carton sealers, conveyors, and the like—to do its job at the right time and at the right speed.
What if a packaging line doesn't achieve that perfect synchronization? At the very least, backlogs and equipment jams could develop; at worst, the line might stop altogether. It doesn't take much for that to happen; just one mistake or oversight can undermine productivity and reliability.
To find out what could go wrong and how to prevent it, we talked to a systems integrator, a packaging engineer, a third-party logistics (3PL) company executive, and a manufacturer of packaging equipment and systems. Here are their tips for avoiding 10 common packaging line pitfalls.
1. Keep your supplier in the loop. The surest way to bring a packaging line to a halt is to run out of corrugated cardboard, labels, thermal forms, foam cushioning, plastic wrap, or other consumable materials purchased from suppliers. That's generally not a concern when it's business as usual. But if, say, you launch a new product or experience a significant bump in sales, your suppliers might not be able to handle the additional demand, cautions Tyler O'Neill, global packaging engineer for the supply chain services company ModusLink Global Solutions. Regular communication and sharing forecasts will help both parties avoid surprises. "If you think something will change, let your suppliers know," he advises. O'Neill also recommends buying strategically from multiple suppliers to ensure the availability of materials.
2. Inspect before you accept. In a high-volume DC, the last thing you want is for defective packaging materials to be inducted into a line. Examples include misprinted cartons and labels that smudge, to name just a few possibilities. You may not find out there's a problem until orders make it part way through the line, O'Neill says, and if your supplier can't immediately deliver replacements, you might have to shut down the line temporarily. A formal protocol for verifying that all incoming shipments of packaging supplies are correct and up to standard will help you prevent stoppages, he says.
3. Minimize refilling of consumables. The more often you have to refill supplies like label stock, liquids, glue, tape, and the like, the more often you'll have to slow down or stop a line, or take an employee away from a workstation to refill them. "That's why whenever we have any consumables in a packaging line we're designing, we like to put in the largest magazine possible," says Jay Moris, president of systems integrator Invata Intralogistics. Adding extra capacity does add cost, he says, but smaller magazines and reservoirs can negatively affect uptime. Furthermore, if a piece of equipment depends on an operator to notice when consumables are getting low, then a larger container requiring fewer refills will reduce the opportunity for an operator to miss a refill signal or wait too long to replenish supplies.
4. Build in redundancy. Automated packaging equipment is expensive, so buyers may be reluctant to acquire and maintain spare equipment. But if a critical piece of machinery goes down, the resulting delays could be far more costly than the price of a spare. "You can save money if you buy cheaper equipment, use smaller magazines, or don't keep spares, but if you end up with two hours of downtime on Cyber Monday, nobody will care about the money you saved," Moris observes. Anything that could not be handled manually is a candidate for backup; if a box taper went down, for example, taping could be done by hand, albeit more slowly, but a label printer could not be replaced with manual labor. Moris recommends integrating critical spare equipment into the line so that in an emergency, you could immediately switch over to the backup machine, rather than have to pull it out of storage and shut down the line to install it. The extra machine can also keep the line moving while the other is undergoing maintenance or consumables are being refilled.
5. Make it simpler. Using complex packaging that requires a lot of folding and forming in the line can really slow things down. For instance, inserts with multiple folds that take some effort to fit into a box correctly typically require many time-consuming touches and may not be easy for people to master. From the standpoint of speed, says O'Neill, a better choice would be to use a prefabricated unit, like a thermal-formed or pulp-molded tray that can be quickly dropped into the box and fitted around the product.
6. Take operating speed into consideration. Each piece of equipment requires a different amount of time to complete its task. To prevent slower machines from compromising productivity, position them farther down the line if the packing method allows. Moris cites the example of a customer that had to print and insert lengthy packing lists into its orders. Rather than hold things up waiting for the multipage lists to print out, Invata placed the printer/inserter farther downstream. As soon as the ordered items are "married" to a shipping carton, the system instructs the printer to produce the packing list, thus allowing plenty of time for printing before the carton arrives at the document inserter.
7. Pay attention to pacing. If bottlenecks develop on a partially automated line, it could be because the pace at which operators are working is not well matched to the flow and speed of the equipment, says Andy Smith, president of Consumer and Industrial Logistics for Genco, a third-party logistics company that has a packaging division. "For example, you could have eight people working on a line, but if one has a four-minute task and another has a two-minute task, that's where the bottleneck will be," he says. He suggests observing the operators to validate the time required for each task and then balancing the work to maintain the necessary pace and ensure a consistent work flow. Lean techniques such as those used to manage manufacturing production lines can help here.
8. "Shake hands" the right way. If the integration of equipment, software, and control systems is not done properly, an order's progress through the packaging line will be a bumpy one indeed. "You have to make sure the software is programmed correctly, that it works in conjunction with every piece of equipment, and that each piece of equipment works properly with the others," says Louis Suffern, e-commerce solutions manager with Sealed Air's Product Care division. At every juncture, he explains, there will be an electronic "handshake" that signals the next piece of equipment to take over. If takeaway speeds or the timing of the electronic handshake aren't correct, a machine could detect a fault and suspend operations. That's why thorough testing—not just of each piece of equipment but also of the software—is critical, he says.
9. {Plan for exceptions. In an automated packaging system, errors like incomplete orders, out-of-register printing, and unreadable bar codes are rare, but they do happen. If you don't design in a protocol for handling errors and rejects, the line will end up slowing or stopping every time there's an exception, no matter how small, says Suffern. Ideally, he says, you want a way to resolve problems and get a package back on the automated line with the least amount of disruption and the fewest touches. One option is to automatically divert exceptions down a conveyor to a workstation specifically set up to resolve errors, and then to reinduct the corrected package at the appropriate station on the line. Suffern has also seen systems that scan packing lists to identify missing items and then convey them to the packing station; that way, workers don't have to leave their posts to complete the orders.
10. Design for tomorrow, not just for today. If your packaging line has no flexibility built into it, you're likely to encounter slowdowns when any change comes along, says Genco's Smith. Equipment that can accommodate changes in box size, graphics, labeling, and other attributes will keep things moving without lengthy shutdowns. "You want to have limited changeovers with the least amount of time to switch over for your product mix," he advises. To get an idea of what may be coming down the road, he says, make sure you're informed about new products in development, special promotions, and issues like theft prevention and entry into new markets that could prompt changes in packaging. "It's a mistake to design for what's happening now and not for where you need to be tomorrow," Smith says.
THINK HOLISTICALLY
One last, important piece of advice is not so much about avoiding a pitfall as it is about changing the way you think about automation. Moris of Invata Intralogistics suggests treating a packaging line as a single, integrated entity, rather than as a collection of individual pieces of equipment. "[Automated packaging lines] are not just the sum of their individual components," he says. "They become an entire machine in themselves." By keeping that in mind, DCs can better maintain their packaging lines' productivity and reliability.
