Shipulski On Design

Archive for the ‘Assembly Time Reduction’ Category

By reducing parts count and easing assembly, one plasma cutter maker explores customized manufacturing.

By Jean Thilmany, Associate Editor, Mechanical Engineering Magazine

Ask nearly any engineer or manufacturer about customized manufacturing and—to a person—they’ll all say the same thing: Have you heard the Dell story?

Dell is offered up again and again as the number one example of customized manufacturing done right and done successfully. Shortly after its founding in 1984, Dell began what it calls a configure-to-order approach to manufacturing. The computer company lets customers customize their own computers on the Dell Web site. Buyers select how much memory and disk space they desire and the resulting computer is manufactured and shipped to them.

The approach has helped the computer maker see skyrocket growth. Last year, it held the second-highest spot for desktops and laptops shipped, behind Hewlett Packard, according to market-share numbers from research firm International Data Corp. in Framingham, Mass.

Manufacturers—particularly electronics manufacturers—have long been taking notice. Many of them are investigating how the configure-to-order model could be put to use at their own companies. And some of them have implemented the method—along with the necessary software to get the job done—with great success.

Take Hypertherm Inc. of Hanover, N.H., maker of plasma metal cutting equipment. The company has recently started allowing customers to choose online from ten CNC Edge Pro product configurations, up from three configurations in the former product line, said John Sobr, head designer on the project.

Hypertherm recently redesigned its plasma metal cutting equipment to reduce part count by 27 percent while doubling the number of inputs available. Customers can now choose from ten product configurations.

Link to full article

Axiom 1 – Time is short, so make sure you’re working on the most important stuff.

Axiom 2 – You can’t design out what you can’t see.

In product development, these two axioms can keep you out of trouble. They’re two sides of the same coin, but I’ll describe them one at a time and hope it comes together in the end.

With Axiom 1, how do you make sure you’re working on the most important stuff? We all know it’s function first – no learning there. But, sorry design engineers, it doesn’t end with function. You must also design for lean, for cost, and factory floor space. Great. More things to design for. Didn’t you say time was short? How the hell am I going to design for all that?

Now onto the seeing business of Axiom 2. If we agree that lean, cost, and factory floor space are the right stuff, we must “see it” if we are to design it out. See lean? See cost? See factory floor space? You’re nuts.  How do you expect us to do that?

Pareto to the rescue – use Pareto charts to identify the most important stuff, to prioritize the work. With Pareto, it’s simple: work on the biggest bars at the expense of the smaller ones. But, Paretos of what?

There is no such thing as a clean sheet design – all new product designs have a lineage. A new design is based on an existing design, a baseline design, with improvements made in several areas to realize more features or better function defined by the product specification. The Pareto charts are created from the baseline design to allow you to see the things  to design out (Axiom 2). But what lenses to use to see lean, cost, and factory floor space?

Here are Pareto’s three lenses so see what must be seen:

To lean out lean out your factory, design out the parts. Parts create waste and part count is the surrogate for lean.

To design out cost, measure cost. Cost is the surrogate for cost.

To design out factory floor space, measure assembly time. Since factory floor space scales with assembly time, assembly time is the surrogate for factory floor space.

Now that your design engineers have created the right Pareto charts and can see with the right glasses, they’re ready to focus their efforts on the most important stuff. No boiling the ocean here. For lean, focus on part count of subassembly 1; for cost, focus on the cost of subassemblies 2 and 4; for floor space, focus on assembly time of subassembly 5. Leave the others alone.

Focus is important and difficult, but Pareto can help you see the light.

The data-driven people in our lives tell us that you can’t improve what you can’t measure.  I believe that. And it’s no different with product cost. Before improving product cost, before designing it out, you have to know where it is. However, it can be difficult to know what really creates cost.  Not all parts and features are created equal; some create more cost than others, and it’s often unclear which are the heavy hitters. Sometimes the heavy hitters don’t look heavy, and often are buried deeply within the hidden factory.

Measure, measure, measure.  That’s what the black belts say.  However, it’s difficult to do well with product cost since our costing methods are hosed up and our measurement systems are limited. What do I mean? Consider fasteners (e.g., nuts, bolts, screws, and washers), the product’s most basic life form. Because fasteners are not on the BOM, they’re not part of product cost. Here’s the party line: it’s overhead to be shared evenly across all the products in a socialist way.  That’s not a big deal, right?  Wrong.  Although fasteners don’t cost much in ones and twos, they do add up. 300-500 pieces per unit times the number of units per year makes for a lot of unallocated and untracked cost.  However, a more significant issue with those little buggers is they take a lot of time attach to the product.  For example, using standard time data from DFMA software, assembly of a 1/4″ nut with a bolt, locktite, a lockwasher, and cleanup takes 50 seconds.  That’s a lot of time. You should be asking yourself what that translates to in your product. To figure it out, multiply the number nut/bolt/washer groupings by 50 seconds and multiply the result by the number of units per year. Actually, never mind.  You can’t do the calculation because you don’t know the number of nut/bolt/washer combinations that are in your product. You could try to query your BOMs, but the information is likely not there.  Remember, fasteners are overhead and not allocated to product. Have you ever tried to do a cost reduction project on overhead?  It’s impossible.  Because overhead inflicts pain evenly to all, no one is responsible to reduce it.

With fasteners, it’s like death by a thousand cuts.

The time to attach them can be as much as 20-50% of labor. That’s right, up to 50%.  That’s like paying 20-50% of your folks to attach fasteners all day. That should make you sick.  But it’s actually worse than that.  From Line Design 101, the number of assembly stations is proportional to demand times labor time. Since fasteners inflate labor time, they also inflate the number of assembly stations, which, in turn, inflates the factory floor space needed to meet demand. Would you rather design out fasteners or add 15% to your floor space?  I know you can get good deals on factory floor space due to the recession, but I’d still rather design out fasteners.

Even with the amount of assembly labor consumed by fasteners, our thinking and computer systems are blind to them and the associated follow-on costs. And because of our vision problems, the design community cannot be held accountable to design out those costs.  We’ve given them the opportunity to play dumb and say things like, “Those fastener things are free. I’m not going to spend time worrying about that.  It’s not part of the product cost.”  Clearly not an enlightened statement, but it’s difficult to overcome without cost allocation data for the fasteners.

The work-around for our ailing thinking and computer-based cost tracking systems is simple: get the design engineers out to the production floor to build the product.  Have them experience first hand how much waste is in the product.  They’ll come back with a deep-in-the-gut understanding of how things really are. Then, have them use DFMA software to score the existing design, part-by-part, feature-by-feature.  I guarantee everyone will know where the cost is after that. And once they know where the cost is, it will be easy for them to design it out.

I have data to support my assertion that fasteners can make up 20-50% of labor time, but don’t take my word for it. Go out to the factory floor, shut your eyes and listen.  You’ll likely hear the never ending song of the nut runners. With each chirp, another nut is fastened to its bolt and washer, and another small bit of labor and factory floor space is consumed by the lowly fastener.

Five-year implementation of DFMA software by Hypertherm creates higher profits and strong business model for improving U.S. global competitiveness

WAKEFIELD, R.I., and HANOVER, N.H.,USA, June 2, 2008—Hypertherm, the world leader in plasma metal cutting technology, has achieved a 600 percent increase in profit per square foot of factory floor space using Boothroyd Dewhurst, Inc., Design for Manufacture and Assembly (DFMA®) software within a five-year redesign program. Correspondingly, warranty cost per unit has declined more than 75 percent during that same period, from January 2003 to January 2008.

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Design2Part Magazine published a good article on DFMA’s ability to cut costs, labor, floor space and improve global competitiveness.

Design for Manufacture and Assembly Helps OEM Reduce Warranty Costs, Boost Profits — Design2Part Magazine

An expert from the article:

Five-year implementation of DFMA software creates strong business model for improving global competitiveness

“We started with a vision to make radical improvements in both product performance and product economies,” stated Mike Shipulski, Hypertherm’s director of engineering. “Hypertherm met both of these goals by aggressively applying Boothroyd Dewhurst’s software within our existing programs for robust design and lean manufacturing. We found their product simplification software made it easy for us to improve a product’s performance-to-cost ratio. Moreover, we learned that DFMA ideas and financial estimates also lead to profound savings beyond labor and part cost, creating a domino effect ‘downstream’ in operational areas of our organization.”

Redesigns get radical improvements using DFMA

Hypertherm, Inc. of Hanover, NH, is among the world’s foremost manufacturers of plasma arc cutting equipment. Founded in 1968 with a staff of two, the company today has 750 employees, with subsidiaries, sales offices, and distributors in multiple countries. All technology development, product development, and manufacturing is done in the Hanover area.

View of the new HyPerformance Plasma HPR130 plasma cutter from Hypertherm. The company used Design for Manufacture and Analysis (DFMA) methodology to radically redesign — and improve — the system’s manufacturability. In the new plasma cutter, system subassemblies took 45% to 89% less time to put together. Assembly floor space opened up by 40%. Warranty cost went down 83%. Cost savings amounted to $5 million over 24 months, which helped the company achieve record earnings and its highest profit sharing on record.

Hypertherm’s products range from lightweight, manual plasma cutting equipment to highly mechanized systems that operate with CNC cutting machines. Its advanced technology serves a global customer base in every industry that depends on quality and reliability in high-temperature metal cutting, such as shipbuilding, construction, farm equipment, rail car and truck manufacture, and plant maintenance.

Recently, Hypertherm engineers tackled a project of mammoth proportions when they remodeled the company’s highly successful HD3070 plasma cutting system — and ultimately created the new HyPerformance Plasma HPR130 plasma cutter. Before the redesign project, the HD3070 sold well and was widely regarded as a standard for robust, high-precision cutting in the industry. Hypertherm wanted to make the product even better.

“We started with a vision to make a radical improvement in product performance coupled with a radical reduction in product cost,” says Mike Shipulski, director of engineering for Hypertherm. He believed that using the methodology of Design for Manufacture and Analysis (DFMA) would help identify unnecessary parts, highlight assembly difficulties that Read the rest of this entry »