Question

The RTC company has technicians that go to the production sites to fix their advanced robot assembly systems when they need repair. During the last 12 months, 28 robot assembly systems needed repair. Each day a robot assembly system is not working (therefore waiting to be fixed) costs the company $5K. The average time to repair a robot is 1 month. Each technician earns an annual salary/benefits of $90K. Assume 20 working days in a month and 12 months/year. They currently have 4 technicians but would like to know if 5 would result in lower total costs. Determine Waiting, Resource, and Total costs per repair with 4 technicians. Waiting, Resource, and Total costs per repair with 5 technicians. Be sure to upload your notes/calculations after completing the exam.

Please provide the answer as:

= WCe = $x, RCe = $x, TCe = $x

=WCe = $x, RCe = $x, TCe = $x

Answer 1

With 4 Technicians and 28 robots each technician works with 7 robots. With each technician the first robot has 0 wait time and 1 month repair time during which it is idle. The secon robot has 1 month wait time + 1 month repair = 2 months. Therefore we see that Robit i has i months of idle time. Hence total robot idle time per technician is 1+2+3...+7= 28 months = 560 days assuming 20 day months. There are 4 Technicians so total days = 560*4 = 2240 days. Hence WCe = 2240*5K = $11,200K. Resource Cost RCe is = 90*4K = 360K. Total Cost TCe = 11,200 + 360 = 11,560K.

With 5 Technicians and 28 robots 2 technicians work with 5 robots and 3 work with 6 robots for maximum efficiency. With each technician working with 6 the first robot has 0 wait time and 1 month repair time during which it is idle. The second robot has 1 month wait time + 1 month repair = 2 months. Therefore we see that Robot i has i months of idle time. Hence total robot idle time per technician is 1+2+3...+6 = 21 months = 420 days assuming 20 day months. There are 3 such Technicians so total days = 420*3 = 1260 days. Similarly for the Technicians working with 5 robots the days = 2*15*20 = 600 days. Total of 1860 days assuming 20 day months. Hence WCe = 1860 * 5K = 9300K. Resource Cost = 90*5K = 450K. Total Cost TCe = 9300 + 450 = 9750K.

Hence 5 Technicians is the more optimal solution.