Assembly: How Standard Can You Get?

For assembly equipment, standardization is becoming the standard. Which leads us to ask: how long before you can order an entire assembly line from a catalog?

Once upon a time in the automotive industry, every plant had its own way of doing things. Lines were laid out according to what seemed best for a particular product; equipment was modified and customized to execute tightly circumscribed tasks. Neither flexibility nor standardization were high on the priority list. Then competition heated up, capital investment budgets shrank, and automakers concluded they had to have the flexibility to build several different models on the same line in order to survive and thrive. To achieve flexibility on a budget, engineers embraced the kind of wholesale standardization of equipment that they might have sneered at just a few years earlier. Now the benefits of standardization seem so self-evident that it is hard to find anyone who will mount a spirited defense of custom tooling. “Once I standardize, I know exactly what to expect the next time I install a line,” explains Jeanne Geary, executive engineer at Ford’s Powertrain Operations, “I don’t have to waste time trying to predict what will happen in a new situation.” Add to that the fact that the economies of scale that result from buying high volumes of the same machines can save 10 to 15% on capital investment, and it’s not surprising that, according to Ted Brown, vice president of business development for equipment integrator Johan A. Krause Inc. (Auburn Hills, MI), “Everyone is heading toward greater equipment standardization; they’re just moving at different paces.”

How Standard Can You Be? That being the case, is there now or will there soon be one standard piece of off-the-shelf equipment automakers can quickly plug in and ramp up? “Not right now,” says Brown, who adds, “But there are elements of standardization that have gotten us a lot closer in the last few years.” He cites his company’s work with Ford on standardizing engine and transmission facilities as an example of how far the process has come. Ford is arguably the most aggressive proponent of standardization of powertrain assembly lines in the industry. Its strategy calls for plants to essentially be carbon copies of each other: same layout, same processes, same equipment. “We try to develop tooling such that we don’t care if a line is running a four-cylinder, six cylinder or V-8 engine,” says Brown. “We want to take out all of those elements that would traditionally drive us toward dedicated machines and isolate the end tooling as the only truly dedicated tooling.”

Much of that can be accomplished today. Electrical panels, human machine interface (HMI) design, guarding, cabling, conveyors and pallets can easily be made common across many lines. Components like cylinders and valves now adhere to a common standard that allows equipment makers to design common mounting fixtures and replace parts based on price and availability, not a supplier’s proprietary design. And even robot programming software, while not entirely interchangeable, has adopted enough similar user-friendly programming features that a de facto standard exists. Beyond that, suppliers are sometimes willing to commonize more sophisticated components with their competitors–for an important enough customer. For example, when Toyota Motor Manufacturing Kentucky (TMMK) installed its Global Body Line (itself part of a new worldwide standard, thus the name) it persuaded robot makers Kawasaki and Nachi to standardize their teaching pendant designs, which according to Pat D’Eramo, general manager, Body Operations, TMMK, slashed training time (the previous line had up to 20 different pendants) and made it a lot easier to rotate operators from station to station.

The Lego Approach. One of the obstacles in the path to achieving one standard but flexible do-all machine is part orientation. As assembly line designers are asked to accommodate a greater variety of products, figuring out how to move and position parts of widely divergent size and shape can lead to unwanted customization. Body assembly operations have embraced common locator points and master jigs that are tied to a specific model as an answer, which essentially allows electric robots to become the standard piece of equipment. But the flexibility gained is usually limited to models built off of the same or closely related platforms.

Engine and transmission assembly, on the other hand, is eschewing the traditional manufacturing lugs used to locate components for an approach that can accommodate several different architectures on the same line. Brown likens the method to building with Lego blocks since you can create some very elaborate structures, but they are all made up of simple, standard parts. In essence, it is a way to achieve the end result provided by custom-designed parts handling equipment by plugging together a varying number of standard modules. Brown explains, “If you just need to find the part and grab it, you need tool X. If you have to grab it and lift it, you need X and Y. Grab it, turn it, lift it–X,Y and Z. They are all standard packages that you add on as you need.”

Catalog Shopping? And that may be as close as the industry gets to a standard piece of assembly equipment in the foreseeable future: many standard and interchangeable modules, but not one machine that does it all. The greater gains will probably come in using those modules to create ever more flexible lines. For example, Brown says that in 10 years we will see assembly lines that switch between building engines and transmissions without re-tooling. And as far as our central question about catalog shopping goes, Brown responds, “We’ve come a long way from dedicated tooling, but I don’t know if we will ever get to the point where companies will be able to order a line from a catalog. However, if we know some basic initial product information and rough production rates, we can order much of what’s needed to equip a line and quickly begin to concentrate on the dedicated tooling. And that’s a lot closer than we have ever been in the past.”