Fresh out of school, you take a job with a small injection-molding shop with two machines (25 ton and 250 ton. On any given shift, there are two workers assigned to each machine one is concerned with setting/loading and unloading while the other packages the final product for shipping. You have been asked to investigate whether you can improve the process, potentially with automation. Having recently re-read The Goal, you are quite aware that adding robots does not necessarily mean an improvement. Make the following process assumptions about the current state 25-ton machine operates at a rate of 2.5 parts per minute (no variation). A worker takes 5-8 seconds to load the machine and 10-12 seconds to unload the machine. The packaging person assigned to this process wraps the part and places it in a shipping box in 9-12 seconds. Once a box is full (25 parts), it is taped and carried to shipping by the packaging worker. This takes between 120 and 140 seconds, including taping and roundtrip travel time. Upon return, the worker packages any parts that have been produced during travel time. The packager sometimes stays a late to finish packaging product at the end of shift (earning overtime) 250-ton machine operates at a rate of 1 part per minute (no variation). A worker takes 10-12 seconds to load/set the machine and 12-15 seconds to unload the machine. The packaging person assigned to this process wraps the part and places it in a shipping box in 18-20 seconds. Once a box is full (8 parts), it is taped and carried to shipping by the packaging worker. This takes between 120 and 140 seconds, including taping and travel time. Upon return, the worker packages any parts that have been produced during travel time. The packager sometimes stays a late to finish packaging product at the end of shift (earning overtime) * . a) If each worker makes $22/hour (fully burdened) per 8-hour shift ($40/hour overtime), the plant runs one shift per week (5 days), 50 weeks per year, how much can be saved by eliminating one packaging worker and just assigning one to cover both packaging processes? Assume the travel time/reach between processes is negligible and rates do not change Clearly state any other assumptions you make Ignoring your solution to (a), you consider the acquisition of a 3-axis robot for $30,000 to set/load and unload the 25-ton machine. The maintenance contract is $1500 per year and the supplier will buy the robot back after five years for $3000. The robot would replace the worker that loads and unloads the machine. The robot would set/load the machine in 5 seconds and unload in 8 seconds (no variance). All other data being equal, is this a good investment? Justify your decision noting that the company uses a 12% rate of return for analyzing investments. Clearly state any other assumptions you make b)
