Audio Innovations of Stillwater, Oklahoma, makes car speaker cabinets and enclosures. Before 2001, it made 12,000 cabinets per month using 130 workers and a labour-intensive process. Then, it was purchased by Rockford Corp of Arizona, which strove to increase its capacity and productivity.
Before the change the process was as follows: 5/8 inch-thick Medium Density' Fiberboard (MDF) was cut into individual sides of the cabinet using a beam saw (a circular saw on a table guided by beams). Then, for each piece a router was used to machine the slanted edges. Next, to cover the four sides a strip of carpet was cut, and the four sides were glued to the strip. Then, the strip ends were glued together. Finally, tire front and back pieces were glued.
The process change involved both the nature of operations and their automation. A machine (called a laminator) was bought to glue carpet to the whole sheet of MDF. Then, the carpeted board is cut into a piece the size of the four sides using the beam saw. A computerized grooving line was purchased to make three V-grooves where the piece will be folded to form the sides of the box. After this, a worker glued the strip ends together. Finally, the front and back pieces were glued.
As a result of the change, the company can make 20,000 cabinets per month using the same number of workers.
1. Draw the process flow diagram before the change.
2. Draw the process flow diagram after the change.
3. Determine the productivity before and after the change.