Q1) The layout of a process consists of two welding machines in parallel, one grinding and one drilling machine. Two panels are released simultaneously to two welding machines where some parts are fitted to the panels using these welding machines. The fitting operation requires 30 minutes per panel. The next step is grinding. Panels are placed in a buffer in front of the grinding machine if the machine is busy. The grinding operation takes 20 minutes per panel. The last step is drilling. After the grinding operation, panels are moved to a buffer in front of the drilling machine if the drilling machine is busy. The drilling operation takes 40 minutes per panel.
(a) Draw a process flow diagram.
(b) Draw a Gantt diagram for the production of TWO (2) panels.
(c) How long will it take to fill a rush order of one panel?
(d) What's the hourly capacity of the process?
(e) Suppose you now have a budget of $6000 to buy additional machines to add to the process in order to increase your capacity as much as possible. The unit prices for the welding, grinding, and drilling machines are all the same, i.e., $2000 each. How are you going to spend the money? Please explain your reasons and calculate the new capacity after investment.
Q2) Metal window boxes are manufactured in two process steps: stamping and assembly. Each window box is made up of three pieces: a base (one part A) and two sides (two part Bs). The parts are fabricated by a single stamping machine that requires a setup time of 120 minutes whenever switching between the two part types. Once the machine is set up, the processing time for each part A is one minute while the processing time for each part B is only 30 seconds. Currently the stamping machine rotates its production between one batch of 360 for part A and one batch of 720 for part B. Completed parts move from the stamping machine to the assembly only after the entire batch is complete. At assembly, parts are assembled manually to form the finished product. One base (part A) and two sides (two part Bs), as well as a number of small purchased components, are required for each unit of final product. Each product requires 27 minutes of labor time to assemble. There are currently 12 workers in assembly. There is sufficient demand to sell every box the system can make.
(a) What is the capacity of the stamping machine?
(b) What batch size would you recommend for the process?