Electrolytic Forming Process

An expensive custom-built product goes through two stages of operation. The first stage is an

electrolytic forming process, served by two independently operating forming machines (working

in prefered order), where the product is built in a chemical operation that must conform to precise

specifications. The second stage is a plating operation in which the product is silver plated by one

machine. Customer orders arrive with interarrival times distributed iid Tria(3, 7, 14) hours. The

electrolytic forming processing time is distributed iid Unif(8, 12) hours. The silver-plating process

plating time is distributed iid Unif(4, 8) hours. The variability in the processing times is due to

design variations of the incoming orders.

The two processes do not perform perfectly. In fact, 15% of the jobs that emerge from the forming

process and 12% of the jobs that emerge from the plating process are defective and have to be

reworked. All defective jobs are sent to a single rework facility, where there are manually inspected

by a worker for iid EXPO(1) hours. Plating rework is sent to a plating rework automated machine

while forming rework is sent to the forming rework automated machine. Plating rework times are

distributed iid Unif(15, 24) hours, while forming reworks are distributed iid Unif(10, 20) hours.

Jobs departing from the rework facility go back to the process they came from to redo the operation

found defective. Jobs that successfully complete the plating process leave the facility. Note that a

job may go back and forth between a process and the rework operation any number of times.

1. Develop an Arena model of the electrolytic forming process, and simulate it for 3 weeks (24

hours of continuous operation).

2. What is the utilization of all the resources?

3. How many plating reworks and forming reworks are in this simulation?

(write all answers using text box in arena)