Questions
1, What are the advantages of the Double-D cells over the circular line?
2. Suppose that the task times of the five workstations in the ring were 30, 25, 20, 20, and 20 seconds, respectively. Explain how four workers, two in each D, can produce the same output as the five workers in the ring.
Sometimes converting an assembly line into two or more cells will actually reduce the staffing requirements. Such was the case in the hardware (mechanical parts) subassembly of recliners in the Franklin Corp. plant in Houston, Mississippi.
The Initial Subassembly Frames (ISF) were assembled by four workers. Then, the ISFs were stored in the ISF queue until they were needed by the circular line, at which time a material handler mounted ISFs on wheeled tables, which were secured to the outer ring of the line with rollers (see the photo below on tiie left). Five workers worked inside the ring. The cycle time in the ring was approximately 30 seconds, but there was a total of 35 seconds of idle time per subassembly assembled in the ring. There were four types of subassemblies but they were similar.