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A Simple Course In Lean Manufacturing for Stamping

October 2012

The following ideas and best practices are meant to be a quick fix that pushes your facility towards lean manufacturing and with a reasonable cost – nothing.

I’m a lean consultant. I like getting paid, but a little free help is a good lean way of getting you hooked on lean manufacturing and helping America’s manufacturers compete despite the hurdles thrown in front of them.

Some of the biggest bang-for-the-buck improvements found on the shop floor are related to stamping. These include:

Stamping Press Staging – Stage everything and make sure you have the new tools/dies and any supporting materials in “on-deck” locations so the second you scoot the “old dies/tools/materials” out of the way, you are ready to slide in the new tools/dies/materials. You should optimize all movements. Just how close can you put everything to where it ultimately needs to be is often only a matter of a little creativity. Just like a pit crew, a changeover team should do as little work as possible while the press is down and take care of tasks like putting things away and cleaning up once the press is running at speed. Consider leaving “machine specific” tools at, or near, the machine. The only exceptions should be for space, safety or maintenance considerations. Does it really make sense to haul tools around the building? It’s generally a “control” issue and nothing more. Stage everything you can at “POU” (point of use).

5S – Make it visual! 5S is more than a buzzword! Hanging tools on shadow boards so they are handy and easily found has saved and earned untold billions for companies around the world! Do what makes sense in your work area without locking all the tools into cabinets and tool boxes. Keep all the “regular use” tools at arms length where possible and never allow the sharing of tools between machines or departments. Never is a strong statement, but you can generally justify the purchase of new tools (over sharing them) in a day or two if you just count the downtime tool sharing costs in production losses. A rare exception might be an extremely expensive meter, analyzer or measuring device that might be centrally located and/or scheduled for other equipment. A clutter-free workplace that has a place for everything and everything in its place is a wise and worthy investment! Insist on it and implement 5S throughout your entire company.

Standardize – Standardize everything you can! As it turns out, lean manufacturing is best achieved through standardization. In stamping that means making dies/tools of similar heights and sizes. It can mean “automatically” locating center points on presses and tools and marking or modifying platens for easy and error-free alignment. Some of the best measurements and alignments are 100 percent automatic! You never need to break out your tape measure or ball peen hammer — or the bigger hammer. Use common plates and risers where possible and consider hydraulic clamping devices and systems. They’re not always appropriate but can often drastically cut downtime when compared to standard clamping.

Design – Design for manufacturing! Sure, you might not have much (or any) control over what design specs your customers send along with the tooling, but when you can, get involved from the inception of stamped parts. We often find manufacturers trying to exceed the limits of the equipment they intend to use in production. If the tool isn’t capable of 0.05 in. tolerances, then don’t expect it to perform at that level. It sounds like common sense, but it is a common practice to expect the unreasonable in stamping, punching and many other processes. To some extent you can even plan for “normal” wear and extend tool life by creative shimming and sectional replacements. True, quality will begin to drift, but it might or might not be of great concern, as not all parts require pleasing aesthetics or dimensional perfection. There might be acceptable options. Of course you must hit all minimum quality standards all of the time! No one is suggesting you compromise on quality, but no one is suggesting you over-spec everything in the name of quality either.

Plan Your Work – Work your plan! Schedule your work so standard tools/dies and/or materials can be left in presses when possible. In the lean world of shorter runs and more changeovers, this technique might save you a lot of downtime and tool movement. The best changeover is still no changeover. Can your tools multi-task? Choreographing the tasks that must be completed for changeovers of all types and regular preventative maintenance schedules on every piece of equipment yields increased up-time and quality and should be a basic part of every plan. Also, try to stick to the schedule. Far too many companies set up for one part, run a few and then switch to the hot part the boss just screamed about before the full run of the current part has completed. Although Lean encourages frequent changeovers, doing them mid-stream is generally counterproductive. A simple decision, you might even say “shop floor protocol” to “finish the run and let the hot part go next” can solve a lot of problems and eliminate a ton of waste. It will also generally reduce the chain reaction of losses spawned from just one premature changeover.

Continuous Improvement – Try new things! It wasn’t that long ago that one press held one tool. That was our father’s and grandfather’s reality. Someone, not sure who to give credit to, came up with the idea that multiple operations could happen at every stroke of the press. Oftentimes that meant carefully setting up various tools in sequence. It was difficult to get it all just right so we began seeing tools that held multiple dies within them (progressive and transfer tools and dies). Recognizing that not all parts of the larger tools wore at the same rate, we started to see customized tools with removable and replaceable components. The evolution of the industry is in the hands of die makers, engineers, operators and mad scientists all around us. What’s next is anyone’s guess!

Of course there is more to say and do when optimizing a stamping operation and making it lean. If you’ll follow the basics outlined here, you’ll be miles ahead of much of your competition and create a considerably more efficient, less wasteful and cumbersome operation.

Lean manufacturing starts with a dream: a vision of what could possibly be. However, the dream is proportional to the actions taken. It’s a great journey and worthy of your best efforts.

Lean Manufacturing Consultant

About the author: Bill Hanover is a lean manufacturing consultant who has been helping manufacturers implement lean to reduce wastes and improve profits over the last 17 years. Feel free to call Hanover if you’d like to find out what lean can do for your business, or if you just need a hand getting it done.