Page 21 - MetalForming December 2009

While many manufacturing compa- nies have studied and implemented the tenets of value-stream mapping (VSM) to help identify and eliminate waste, plenty of high-volume shops are evolv- ing to shorter-run production and tak- ing on a high-mix low-volume model. Shops such as these—including D&S— that exhibit multiple, merging value streams can optimize their operations by using VNM. As described in a paper written several years ago by professors at The Ohio State University, VNM allows a company to map the complete network of flows in the value stream and, according to the paper’s authors, “supports facility improvements to merge/streamline multiple flows in the facility, such as the creation of manu- facturing cells and improvements in the current material-handling meth- ods.”
At D&S, improving the flow of mate- rials from its gateway work centers— lasers, oxyfuel and plasma-cutting machines—and into its fabrication area of press brakes, machining centers and the like, and eventually on to assembly and robotic welding cells, has helped the firm eliminate delays and waste in its material-handling operations. Forklift traffic has been reduced by half, aisles are wider and equipment cells are roomier, eliminating hazards. And, all of the firm’s performance measures have improved—on-time delivery is up 25 percent, scrap costs have dropped by 25 percent, customer rejects are down by 30 percent, and lead time has dwindled on some parts from two weeks down to five days, and for other parts from six to eight weeks down to just three to four weeks.
“Along with reorganizing our work flow using value-network mapping, a key technology enabler to allowing us to increase speed through the plant has been installation of a finitely con- strained scheduling system,” says Carl- strom. “We used to schedule backwards with infinite capacity, as many compa- nies still do. This would lead to over- loaded work centers.”
D&S operates four robotic arc-welding cells and recently implemented offline pro- gramming to boost productivity from the cells. Thanks to offline programming, the company can justify running work-order quantities as low as 15 through its robotic- welding cells, rather than through its manual welding booths.
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A Finite Constraining Scheduling System
Earlier this year, D&S implemented a finitely constrained scheduling system based on new ERP software from Epicor called Vantage. The software allows the firm to identify constrained work cen- ters and put limits within the schedul- ing software to balance production flow.
“Before, we had a series of moves and queues and built-in delays to some of the processes, because the work cen- ters were overloaded and we needed a cushion to meet our customer dates,” Carlstrom says. “Now, with balance to our flow, we have taken those moves and queues, which at times would be two or three days long, down to just one day, or less in some cases. As a result, our lead times on some work have been cut in half since we’ve eliminated the schedule delays we used to have to plan on because we were not finitely controlling our constrained work centers.”
D&S’s new ERP software relies on up-to-the-minute production data coming from the shop floor, thanks to implementation of plant-wide bar-code scanning to track labor content, control work flow and manage work in process.
“Gone is the old philosophy that if I don’t get it done today I can do it
tomorrow,” says Carlstrom. “We have a much more disciplined and committed approach to getting the work done according to schedule. So where we once maintained a warehouse to store component parts in 40 different rack locations, inventory storage now takes up just 10 racks.”
Supplier of the Year
D&S credits its streamlined workflow and improved scheduling system with helping it earn supplier-of-the-year sta- tus from one of its customers, Parkson Corp., a Ft. Lauderdale, FL, supplier of components and systems for water treatment. And, the firm recently was deemed eligible for a $250,000 state income-tax credit through the West- ern Wisconsin Technology Zone.
“We’ll be able to use the credit to reduce our state income tax,” says D&S chief financial officer Tony Ptacek, “earning credits through our capital investments and job-creation and job- retention efforts.”
Among those efforts was implemen- tation of offline programming for its robotic-welding cells, which MetalForm- ing covered in a feature article published in the February 2009 issue; http://archive. metalformingmagazine.com. MF