Assembly in Action: Simulation Program Boosts Workcell Throughput
Winning a large contract to supply internal antennas for the mobile phone market proved to be more difficult than component manufacturer N&R Engineering’s (Lancashire, England) management team had hoped. When production began, it became apparent that there was a problem associated with deformation of the aluminum wire during the forming process. As a result, an extra operation was require to straighten two legs on the component so they were parallel.
After a couple of months, it was obvious that the cell was underperforming, so the company called Northern Technologies (Lancashire), a training, technical and business support center.
After studying the problem, Northern Technologies realized that cell simulation modeling in Delmia’s (Troy, MI) Quest software, in addition to lean manufacturing techniques, would help the company improve productivity.
The U-shaped production line consisted of an automatic wire-cutting machine feeding five workstations. Each had a different manual operation—fly pressing, crimping, trimming, assembly and coining. Data was gathered about the individual process times, cell layout, operator positioning, part handling and the rate at which the wire cutting machine was feeding the cell.
A new cell layout was created in Quest and run through a series of statistical simulations using the process data previously gathered. The operators were then invited to view the various scenarios and provide their input. After a few changes, the layout was finalized.
The U-shaped cell of operators facing outward became a C-shaped cell with operators facing inward, allowing them to see and talk to one another. Overreaching during parts transfer was eliminated.
The wire cutting machine speed has been decreased so that it matches the longest individual operation within the cell. The machine has also been elevated. This allows the wires to be gravity-fed into the first operation. Then, racks holding just 20 components in a standard orientation are placed at various stages of the process.
Because the new process involves a pull system, the operators now know that if the next process downstream already has a full rack of parts, then no more parts should be produced until there is space on the rack.
"Increased production capacity and more flexibility has led to our customer awarding us further contracts to supply their operations in the United States and Australia. Cell throughput has increased from 2,250 parts per shift to 3,520 parts per shift. At the same time, our inventory has decreased from almost 1,000 parts to 120," says Mark Stinchon, plant manager at N&R Engineering.
"The cell has improved workflow and ergonomic conditions. The operators actually prefer the new environment. There have also been several additional benefits. The wire cutting machine no longer jams, because it operates at a slower speed, and quality is easier to monitor, owing to the pull system’s rules," he continues.
For more information on simulation software, call 248-267-9696 or visit http://www.delmia.com.