Page 40 - MetalForming March 2014
P. 40
Ready; Set; Lean
“When a manufacturer can reduce change- over times and run smaller batches (including one-piece flow), it has the ability to produce what a customer needs when he needs it.”
38 MetalForming/March 2014
www.metalformingmagazine.com
determine if the part is a kanban prod- uct or not by looking at order frequen- cy. A part with an order frequency that stretches over a long period (more than seven days) will cost more to keep in stock than if it was processed in a sin- gle-piece flow.
Lead time is the time required for delivery once a kanban has been authorized for production. Factors that influence lead time:
• Number of orders in queue ahead of the customer’s new kanban
• Machine cycle time
• Quantity
• Changeover time
Lead time, expressed in days or frac-
tion of a day, is only an estimate, due to the four previously mentioned factors. Shops must monitor and update these influencing factors to ensure they have the correct number of kanban cards.
Safety time, expressed in days or fractions of a day, is the time allotted to compensate for unexpected events that can occur—machine downtime, scrap, no operators and variation in demand.
Container quantity is the number of products that a pallet or a container will hold, expressed in units.
The Ability to Make Any Part, Any Minute
When a manufacturer can reduce changeover times and run smaller batches (including one-piece flow), it has the ability to produce what a cus- tomer needs when he needs it. Gone are the days when you had to either attempt to forecast demand or wait for orders to come in before determining what parts to make, create drawings, cut sheets to fit on the turrets and create dynamic nests. The key to success: The ability to make any part, any minute.
Typically, customers start looking at new automated fabricating equip- ment to alleviate capacity issues, high costs and the difficulty experienced in moving parts in a synchronous flow. Big problems really occur every time a special is entered into the system, cre- ating disruptions along the whole chain of operation from design to assembly.
Some fabricators have arranged
machines in manufacturing cells. When done properly, they experience a much smoother process in the timeline from order to fabrication of parts to final assembly. However, a cell oftentimes cannot handle all of the parts in a syn- chronous flow. According to several studies, most fabricators run about 20 percent of their parts in a synchronous flow, the remainder in a batch system.
To satisfy today’s market demand, it’s vital to investigate the possibility of automating the entire process to accel- erate time to market. The fact that a new automated system can cut lead time in half is attractive, since the greatest advan- tage over competitors is delivery time, design and cost—or agility, flexibility and speed. The gains of an automated system compared to conventional production systems are a decrease in the timeline from order to invoicing, which means a fabricator can:
• Run with practically no WIP.
• Redesign parts for a lean approach, so that part production and assembly can be accomplished in hours instead of days.
• Test new models in weeks instead of months.
