=+Most of the work in Manufacturing Department B is done by machine, but before the wheels are sent to the Packaging Department they are inspected for defects. Poorly made wheels are disassembled by hand and sent back to the beginning of the Manufacturing Department B line for rework. Thus, any wheel that was made incorrectly and fixed takes more than twice as long to finish as a wheel that was made correctly the first time. Any wheels still not useable after rework are thrown away.

The same amount of ball bearings is requisitioned from the materials storeroom daily. Any leftover ball bearings at the end of the day are discarded. Ball bearings are measured by weight.