1-15

The number of cars arriving per hour at Lundberg's Car Wash during the past 200 hours of operation is observed to be the following:

# of Cars arriving Frequency
3 or less 0
4 20
5 30
6 50
7 60
8 40
9 or more 0

a) Set up a probability and cumalative possibilty distribution for the variable of car arrivals.

b) Establish random number intervals for the variable.

c) Simulate 15 hours of car arrivals and compute the average number of arrivals per hour. Select the random numbers needed from the first column of table 15.5 chart 1, begining with the digits 52.

d) Compute the expected number of cars arriving using the expected value formula. Compare results obtained from the simulation.

1-18

An increase in the size of the barge unloading crew at the Port of New Orleans (see attached 15.5, Chart 1) has resulted in a new probability distribution for daily unloading rates.

Daily Unloading Rate Probability
  1        0.03
  2        0.12
  3         0.40
  4         0.28
  5         0.12
  6          0.05

a) Resimulate 15 days of barge unloadings and compute the average number of barges delayed, average number of nightly arrivals, and average number of barges unloaded each day. Draw random numbers from the bottom of table 15.5 chart 1 (attached) to generate daily arrrivals and from the second from the bottom ro to generate daily unloading rates.

b) How do these simulated results compare with those in the chapter?

1-25

Stephanie Robbins is the Three Hills Power Company management analyst assigned to simulate maintenance cost. The total simulated maintenance cost of the current system is $4,320.
Robbins would now like to examine the relative cost effectiveness of adding one more worker per shift. The new repairperson would be paid $30 per hour, the same rate as the first is paid. The cost per breakdown hour is still $75. Robbins makes one vital assumption as she begins-that repair times with two workers will be exactly one-half the times required with only on repairperson on duty per shift.

Repair time Required (hours) Probabilty
1/2 0.28
1 0.52
1 1/2 0.20
_____
1.00

a) Simulate this proposed maintenance system change over 15 generator breakdown period. Select the random numbers needed for the time between breakdowns from the second-from the bottom row of 15.5 (attached)chart 1 (begining with digits 69). Select random numbers for generator repair times from the last row of the table (begining with 37)

b) Should Three Hills add a second repairman?

Attachment:- charts.zip