Modular conveyors can be set up to meet part routing requirements in fairly short order. What’s more, integration is with gravity-feed conveyors, wheeled parts trolleys and associated equipment is facilitated.
Setting up a lean operation, where the wastes of excessive movement and inventory are clearly eliminated, requires understanding material flows, people flows, and information flows.
Bosch Rexroth (boschrexroth-us.com) makes a variety of equipment for flexible material handling, the most familiar of which are undoubtedly the structural aluminum components and associated equipment that are seemingly assembled like a Hot Wheels track (without the loops, of course). So you might think that when talking with Kurt Greissinger, product marketing manager, about developments in material handling the emphasis would be on structural aluminum components for conveyors and associated equipment.
And you would be wrong.
The reason is that at Bosch Rexroth, they have done considerable developmental work on lean material handling. They actually send people out to talk at conferences and at companies about lean and how it can be deployed for economy and efficiency. And about that subject, Greissinger says, "Material flow is only one part." Yes, Greissinger explains, it is essential to do a spaghetti diagram, to determine just how the material flows within a facility and how or if it is possible to rapidly and effectively modify that flow in order to accommodate changing demands. But it isn't just within the facility, but beyond the loading dock to the suppliers' facilities. If the suppliers aren't lean, then it is going to be truly difficult to be lean in your own facilities.
There are two other pillars to the structure. One is people flow. The other is information flow. Although the "flow" is associated with all of the terms, and although it implies movement, Greissinger acknowledges that in the case of people, they may be stationary. While they may not necessarily flow, things should flow to them: It is all about making a determination of where they work and then making it as easy as possible for them to do their work. After all, one of the seven forms of waste is people moving too much to get their work done. So part of the configuration for a lean system is to setup the material handling system such that there is no interference with the high-value add of assembly work. This means that no matter if it is a U-shaped cell or an assembly line, it is likely that it is important to have parts fed from the rear, or the side where the people aren't assembling. Gravity-feed systems, flow racks, and the like come into play.
As for information flow, it is important that there is an understanding of both how work instructions and job orders are received on the shop floor, whether it is digital or word of mouth, whether it ends there or is communicated onward.
According to Greissinger, because the corporate parent Bosch is (among other things) an automotive supplier, back in 2001, there was a recognition of the need to deploy lean processes to better serve its customers for products such as fuel injectors. This led to the development of the Bosch Production System. Which then, in part, led to the develop-ment of the tools and deployment techniques that are not only used by Bosch companies, but are available commercially through Bosch Rexroth.
material flows, people flows, and information flows
"One tenet of lean is flexibility," Greissinger says. "So the structural aluminum framing comes into play." He contrasts this with assembly systems where there are weldments placed in concrete foundations. Those become monuments, and are anything but flexible. That said, there is a recognition that sometimes companies must go well beyond manual assembly and to automate. Essentially, if there is complete understanding of what on-going production demands are going to be and there is a considerable volume (e.g., tens of thousands of parts, say), then, as he puts it, you can "afford to automate."
On the other hand, if there is uncertainty in the product mix, the lifecycle, and/or the volumes, then chances are going with a more manual system is probably best: "People are more flexible than automation," he points out. (However, if the cycle time is shorter than from 15 to 60 seconds, which is, he says, what is a range for manual operations, then it may be necessary to automate regardless.)
With the limitations of funds for capital investments that are so characteristic of today's enterprises, taking a lean approach to material handling (and the operations that the material handling serves) is key. Greissinger calls it "creativity over capital." By better understanding flows, by appropriately setting up material handling, then it is possible to free up the money that may be tied up in inventory, and consequently setup a virtuous cycle within the organization.