Apr 04 2015

Improve Productivity! Reduce Scrap!

Published by at 4:02 pm under management,processing

Sounds like an ad from a sleazy Used Car dealer, Yes? But the folks who sell the latest gizmos essentially use the same wording.

QUESTION: What’s the best way to maximize your profits?
ANSWER: (1) Fair pricing – you can easily fix that. (2) Improve your productivity – this is something you can also fix. The overall cost of a molding run has two basic components – the idle time of the machine during setup and the yield required to fulfill the order.

Injection Molding is a mass production technology. However, once the set up costs are less than 4% of the overall run costs, spending money on Single Minute Die Exchange and other gizmos has a very small return.

HOW TO SHORTEN SET UP TIMES – Let’s call “set up” the idle time from the last part to the time you produced good parts on the new run.

1. Wouldn’t it be nice if the mold was at the press, the material was dry because you used portable dryers and quick change mini hoppers on the machine, you had all the waterlines and ejector bars at the press, the crane (or whatever) was available?

2. Wouldn’t it be nice if the Set Up Crew were there and did the setup without having to troubleshoot other presses, go on break, relieve other operators for lunch, and blah-blah during the setup?

How do we do this? Training. ‘Nuf said’
HOW TO LOWER SCRAP
I’ve seen too many operations that boast about ‘Exceeding their customer’s quality expectations’. Why? Do you pay more for a perfectly done medium rare steak at a restaurant? Nope, But you’ll send it back (reject it) if it isn’t medium rare.

Customers are willing to pay for delivery performance, not excessive quality. This means they got parts that worked, in the quantity they wanted, when they wanted it. While the buyer may whine about ‘better quality’, he only wants parts his customers will not reject.

As above – Injection Molding is a mass production technology – This means with reasonably maintained equipment; the quality of the first dozen shippable shots should be (within normally expected variation) the same as the last dozen shots a million parts later.

1. Wouldn’t it be nice if you maintained your equipment? If you can understand why you change the oil in your car, it’s no leap of faith to understand the need for a scheduled preventative maintenance program for the molds and machines.

2. Wouldn’t it be nice if you didn’t stop the run? I had a friend to ran an 8 machine shop running nasty engineering resins with 5 people 24/7. How’d she do it? Simple: she believed there was no such thing as a semi-automatic process. She’d adapted sprue pickers and such to load inserts and unload parts. The parts landed in pre-made boxes that had a weigh scale under them. Those that needed nest packaging were done by some snazzy end of arm tooling on the robot. When the box was full, it rolled down and a new box took it’s place. Since the machine had a counter, when the run was over, it shut itself down. If the machine malfunctioned, it would lower it’s own heats, open the mold and send a text message to whoever was ‘on call’ for them to come into work (regardless of the hour) to fix it.

All this didn’t cost a zillion dollars. The machine’s computer can be programmed, roller conveyors and weigh scale equipment are in-place technology. Telling the machine to send a prewritten text message over a cell network is easy and cheap (what do you think your home security system does?).

3. Wouldn’t it be nice if there was a cure for the “Down Stream” syndrome. I’ve always been amazed that inspectors and operators “think” they know what an acceptable part is but they really don’t “Know”.

The Down Stream Syndrome is the fear that the lot will be rejected by someone downstream from them. In response to this fear they arbitrarily reject acceptable parts! If your customer wants higher quality, he need only respecify the parts whilst you revisit the price. The quality specs should be clear and simple – “Free of manufacturing defects” is neither. If they don’t give you quality standards, give them yours and a nice e-copy of SPI’s cosmetic specs so they can read about clear and simple.

4. Wouldn’t it be nice if your people understood Injection Molding. The process doesn’t make scrap, there’s no such things as ‘secret settings’ and you don’t need to adjust everything when the sun goes down, or it’s winter. (Hint – it’s really dark inside the barrel – the plastic doesn’t know what time it is, what part its making, what the weather outside it is, and most importantly whether its molding parts in Boston or Bangladesh. Because there’s a few inches of very hot steel between it and the outside environment!)

People are your biggest cause of yield losses. Not just the setup crew or the inspectors; but everyone. Example: A scheduler sees a job coming up and can pick two identical machines. One is running clear acrylic, another is running black ABS. The one with black ABS is due to finish its run three hours earlier than the one running clear acrylic. BUT the new job is clear HIPS. Which machine does he schedule it in? You guessed it, the one with black ABS because to him they both require a material change. What he doesn’t know that going from black to optically clear requires a lot of purging and for a few hours into the run, little black specs will show up killing the yield. Why’d he make this decision? – He didn’t understand the molding process.

Untrained people are not stupid, they are naive. The concepts of the molding process, if we stay away from the PhD test tube bangers, and the Black Belt Ninja statisticians who seem to think there’s always money to keep the plant open regardless of how much product they reject, are easy to understand.

Who do we train? The problem with training is it usually costs a fortune (airline tickets, hotels, meals, evening trips to naughty establishments, not to mention the training itself!). Even worse, most seminars are the “take-your-own-notes” variety and we send people to them to learn but not to teach others when they come back.

Your most valuable assets are your people. Don’t send them off to ‘the big city’ to sit in a hotel meeting room and eat a rubber chicken lunch. If I gave you an intensive one day seminar (100%) in two days you’d remember 50% of what I taught, a week later you’d be able to use 10%. That sucks!

But what if I came to your plant where everyone got a textbook that explained what was taught so you didn’t have to take notes? We set up the class in a meeting room, and have pizza for lunch. It’s tailored to your operation not a ‘one size fits just about everyone’ seminar. What if we had as many people as possible attend – operators, setup, QC, schedulers etc.? Obviously we wouldn’t have to worry about a setup tech that thought his knowledge was his job security and should be kept secret. Also, that kid who never speaks up could turn out to be the best new tech in the whole company!

With a little training/understanding most operators can make the first few adjustments to troubleshoot common defects. This keeps the machines making good parts and utilizes the tech’s time more productively.

With your book in hand you need only remember the topic, look it up and re-read was taught in the class if you ‘temporarily’ forgot it.

THE RETURN ON INVESTMENT
If you were to send eight people out for training over the space of a year to my public seminars, that would cover the costs of my coming to you (usually anywhere in North America) and putting on a full day’s seminar for 20+ people, complete with textbooks. If you went to the other guy’s seminars the breakeven costs drop to between three and four people.

I had a client whose ISO certification said “everyone” was trained. I did all three shifts in the space of three days, for what they could have sent one guy to the week long training in the hinterlands of Northern Great Lakes.

To Summarize. TO IMPROVE YOUR PROFITS – Spend your money intelligently.
1. Maintain your molds and Equipment
2. Have everyone understand and know what the customer considers acceptable.
3. Injection molding is an automated process. Yes, it is possible to automate and stop knob twisting.
4. Train the troops. This isn’t magic black box stuff.  See SEMINARS on this site.  I do public and in-house.  E-mail for details.

Improving your profits mean you can do more with a smaller head count where your can afford to pay your people more so they won’t quit on you.

OR you can whine about low yields, the (hilarious) ‘explainable variances’, justify not training (“every time I get someone trained they quit and go down the street for ten bucks a day more.”) and low profits.

Your choice.

One response so far

One Response to “Improve Productivity! Reduce Scrap!”

  1. Dennis McLaughlinon 09 Apr 2015 at 11:56 am

    Bill, hope every thing is going ok with you.
    Nice article, hard to get “molding foremen to implement”, Dennis.

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