Managing Downtime

How long does it take to clean a tablet press and ready it for the next production run? It’s a question tablet press manufacturers get all the time. They usually reply that it depends on the number of stations, the tooling configuration, the last product made on the machine, maintenance needs, and any number of other variables. And all that’s true, but for a better answer, take a moment to watch a real changeover. Many of you will discover that you’re missing a big opportunity to improve productivity. 

It’s simple: When the tablet press stops, downtime begins, and if you don’t focus on getting that tablet press back into production as quickly as possible, your efficiency isn’t what it could be. Consider it a race, and in this race, your strategy is the same as a NASCAR pit crew. Have you seen these guys? Yes, they’re fast, but each also has an assignment. Most important, they have all the tools they need to do the job: getting that racecar (tablet press) back in action as soon as possible. 

Time-and-motion experts would have a field day with most of the crews responsible for tablet press changeovers. It’s common to see a tablet press stop before anyone even thinks of gathering all the tools and materials needed to perform the changeover. And there the press sits, unattended. 

But a production tablet press, like a baby, should never be left unattended; it should be either making tablets or undergoing a changeover for another production run. So if you’re serious about reducing downtime, be ready before you stop the press. Emphasize this with the tablet press operators: Before the machine stops, your crew should be ready to remove the punches, clean out the cams, lubricate the tooling, visually inspect everything, make repairs (if any), and put the press back into production. The amount of time these tasks take is directly related to how well prepared your crew is, which means having the tools, materials, and staff in place and ready, not wasting time searching for this, that, or the other thing. 

No one should be surprised by having to stop the press. It happens every day. Don’t abandon the machine in search of what you need. Have it there. This includes hand tools, power tools, cleaning supplies, lubricants, flashlight and mirror, and common spare parts (scraper blades, punch seals, and dust cups). 

A few weeks ago, I witnessed a 30- minute delay while operators searched for a brush to clean the punch sockets. Then — oops — they also needed an Allen wrench. They found two different wrench sets, but both were incomplete. Twenty minutes later, they found the wrench they needed. Does that sound like a good use of downtime? Of course not, but this isn’t an exaggeration. It’s real, and it happens every day. 

Still, be careful about pointing a finger. This isn’t always an operator problem; it’s often a management problem. Sure, managers push operators to turn the presses around quickly, but the message is usually interpreted as, “Do it fast and cut corners if you have to.” That is exactly the wrong way to reduce downtime. Fast but incomplete cleaning will actually increase the frequency of cleaning and that will increase total downtime. Then add the time wasted looking for the items needed to change over the press, and downtime (actually machine-beingleft-alone time) grows that much more. 

So watch the in-between time. Take a stopwatch and pen and paper with you at the next changeover. Use the stopwatch to measure how much time is wasted getting the tools for the job. Use the pen and paper to list the tools needed to make your “pit crew” cut downtime and make cleaning more effective.

Michael Tousey | Techceuticals