Meritor is so pleased with the outcome from previous suggestions that the consultants are invited back for more work. The consultants now suggest a more complete robotic automation of the making of muffler assemblies and also a reduction in container size to eight per container. Meritor implements these suggestions and the result is that the muffler assembly fabrication cell now averages approximately 32 assemblies per hour, and the catalytic converter assembly cell can now respond to an order for a batch of catalytic converters in one hour. The safety stock remains at 12.5 percent. How many kanban cards are needed?