Assembly in Action: Manufacturing Cell Doubles Efficiency
Together with Bob Kraus, a team leader, they went over the orders and schedule. They have realized that if it wasn't for the new manufacturing cell, they wouldn't have met the schedule. Or they would've had to hire another person. "Our production process included several intermediate steps during the building of the subassemblies. The Raven Super Cell has enabled us to skip these intermediate steps and assemble the instrumentation on demand. This has allowed us to be extremely flexible when building to order," says Fred McCoy.
With Cincinnati Test Systems' old bench assembly process, an operator assembled 10 doors and stored them. Other subassemblies, such as manifolds and regulator banks, were next in line. The operator moved back and forth between partially completed subassemblies, trying to match them with the custom order. Inventory was a nightmare. It was almost impossible to keep track of all assembled components. Labor was wasted on handling the parts several times and by following several intermediate process steps. "Before the Raven Super Cell, subassemblies had to be built to meet delivery times. It cost us money to build subassemblies as separate processes, and it cost us money to stock them and track them when we needed them. With the Raven Super Cell, we are building to order," says Chris McCoy, department manager.
Cincinnati Test Systems was concerned that its instruments were too big for a rotary table. It was also concerned that the complex models would slow down the operator, making it impossible to assemble different combinations. When the company was almost convinced that its instruments were not suitable for a rotary table, Raven Engineering developed a complexity matrix.
Over the years, Cincinnati Test Systems developed different tooling to assemble doors, manifolds and wire harnesses. Raven Engineering analyzed these designs and combined them into a plastic plate with color-coded information dots. "Before I saw the machine for the first time, I was very skeptical. I didn't think that they could do better than my current bench process. The machine surprised me. I knew right there that it's going to assemble instruments faster," remembers Bob Kraus.
Raven Engineering concluded that only a few percent of components would be affected by complexity. The majority of the components would be the same. The analysis proved to be correct. The operator running the Raven Super Cell is able to assemble at least three different sizes of instruments with the complexity reaching several dozen.
The Raven Super Cell can build four instruments at a time. The operator repeats the same manual motion and advances the table with a foot switch. It didn't seem that this would make much difference in assembly time, but it did. With both hands free, the operator pulls parts from rotating bins above the main table and performs assembly tasks. Together, the part bins and a dial table work like the hands of a clock. Each full revolution of a table advances the part bins one position; the operator pulls different parts for the next assembly step. Rotary part bins are located ergonomically in the middle of the table a few inches from the fixtures.
Raven Engineering wanted the cell to be self-sufficient. The machine had a 16-inch-wide horseshoe-shaped table in the back that wasn't used. Raven Engineering proposed using that space to performance test assembled instruments. Cincinnati Test marked up the prints, and Raven Engineering supplied a machine with air and power hookups. The four complete instruments are cycled in the test area of the machine, while the next four are being built.
The Raven Super Cell was easy to install and operate. "The launch went very smoothly with very little transition time. Up and running in a day!" exclaims Fred McCoy. "The Raven Super Cell was easy to install using the boot for forklift pick-up, integrated in the machine. The unit was also easy for all of our assemblers to learn and use. The quick learning curve has enabled the machine to increase our output capability almost instantly," adds Chris McCoy. With the old assembly operation, an operator could assemble 4.3 instruments in 6.5 hours. Now, the same operator can assemble 12 instruments in 6.5 hours on the Raven Super Cell. That is a 279 percent production gain.
The Raven Super Cell looks like a piece of artistic, contemporary furniture, but it is far more than that. "The significant part about the Raven Super Cell is that we are proud when we bring potential customers to the assembly area. The machine makes a better impression because the customer doesn't want to see their instruments being assembled on the picnic tables. They want to see a manufacturing facility," says Chris McCoy.
For more information on rotary tables, call 812-336-9148, visit www.raven-eng.com or Reply 4.