How to Lean Micro Machine with SMDE and Single Unit Pull.
By Dr. Walter Schnecker & Steve Carter, Datron Dynamics, Inc.

But, the origins of lean manufacturing on American soil can be traced back to the 19^th Century and it could be argued that SMDE is actually an American invention. In fact, in 1911, Frederick Winslow published a form, for use by The Midvale Steel Company, entitled “Shop Management.” This form is clearly divided in half with the left side detailing all operations occurring before or after machining (set up and change over) and the right side containing just the machining operations (or actual production). The document shows a staggering 47 steps on the left side and only 14 on the right side.  Where Winslow faltered is that after illustrating this inequity, he chose to focus on optimizing the 14 machining steps to make them more efficient rather than eliminating some of the 47 steps required for set up/change over.

Nonetheless, there are other signs that that SMDE was already being employed during this period.  In the introduction to Frank Gilbreth’s Motion Study (1911) Robert Thurston Kent wrote, "In a certain shop with which we are familiar a piece had to have several holes of different sizes drilled in it, a jig being provided to locate the holes. The drills and the sockets for them were given to the workman in a tote box. The time study of this job revealed several interesting facts. First, after the piece was drilled the machine was stopped, and time was lost while the workman removed the piece from the jig and substituted a new one. This was remedied by providing a second jig in which the piece was placed while another piece was being drilled in the first jig, the finished one being removed after the second jig had been placed in the machine and drilling started."

Nearly a century later, Datron Dynamics, taken this methodology and turned it into a science – providing manufacturers of small parts with a means of implementing SMDE and achieving Lean Manufacturing. Here’s how it works:

Lean manufacturing is a concept that generally requires a change in the thinking process of everyone involved in the company trying to achieve it. The majority of the work is of an organizational nature and needs to be done in house. In addition, unless the manufacturing tools you are using, are capable of adapting to new challenges, re-organizing and changing your procedures can only get you so far. Well, with all the effort, time and cost associated with this transition, wouldn’t it be great to have manufacturing tools flexible enough to help you achieve your goal of lean manufacturing quicker?

Looking at only two aspects of lean manufacturing will make clear what can be done without unreasonably inflating the cost of equipment.

For those as unfamiliar with the concept, SMDE, is the goal of changing the production tools (the die) within a single minute. Now, this is a challenge for most manufacturing environments. Particularly when you consider that 30% of the time is consumed by planning, 5% is used for the actual exchange of the dies, 15% is needed for tramming and 50% is associated with run-offs and adjusting. But, what if you could eliminate the tramming and the adjusting phase? According to the time consumption statistics detailed above, this would eliminate a whopping 65% of the time required for job change over or “die exchange”. Well, our machine design engineers at Datron came up with a solution to build workholding receptacles right into the machining bed. Then with a boss-in-cavity system, our Quick-Pallet workholding solution registers a sub-plate in X, Y and Z, thus eliminating time consuming process of tramming and adjusting.

Single Unit Pull calls for the ability to make a part and all of its’ sub parts, when, and only when, ordered. The purpose is to reduce stock (inventory) and the cost associated with it (overhead). Again, this is a challenging concept for most manufacturers. Most manufacturing set ups are designed to make a batch of one type of parts and then change the set up to make another type. Other set ups are designed to have parts made on one machining station and then transported to another station. While this style seems efficient with respect to Single Unit Pull, it is often a costly approach warranting multiple machines along with the labor needed to get the parts from point A to point B. But, what if a machining system could actually be adapted and changed quick enough, to help achieve Single Unit Pull on one machine. Again, the answer is Quick-Pallets. Because the changeover between producing one type of part and the next one is so fast that Single Unit Pull becomes an attainable target.

The two aforementioned aspects of lean manufacturing, are, of course, only a very small part in the chain of events that need to take place. But nonetheless, they illustrate how something small and not very expensive can have a huge impact on efficiency and therefore on the bottom line.

Lean Manufacturing will be the key for US companies to withstand and weather the “China Syndrome” as well as the fierce competition that’s resulted from competitors just trying to stay afloat. Our salvation will lie in being able to eliminate any waste and any inefficiencies in our manufacturing processes. Besides the need to streamline our manufacturing processes, we need tools and technologies that help us along. Companies that buy used and antiquated technologies because they are offered cheap, are essentially positioning themselves for failure. How can anyone expect to tackle tomorrow’s challenges with yesterday’s technology? We need modern equipment designed specifically with the tenets of lean manufacturing in mind.

The good news is that there seems to be great interest in lean manufacturing and companies that ignored it in the past are now looking in that direction. Will a trend toward “Lean” be a big deal? Count on it. The longevity and prosperity of North American manufacturing depends upon it. Keep in mind, the later one starts on the journey the longer it will be until he gets there.