Instructions
Simulate the repair/replace example on page 333. The options are: replace end of day 3 replace end of day 4, repair if breaks on day 4 replace end of day 5, repair if breaks on day 5 repair when it breaks (There is a random number table under Data files if you want to try this by hand.)

I J K L M 1 FIGURE 12.3 This data table improves the reliability of the com- puter simulation recorded in Figure 12.2 by perform- ing 1,000 replications instead of only 14. Data Table for Coin-Flipping Game (1,000 Replications) 2 3 4 5 Play 6 7 1 Number of Flips Winnings 5 $3 3 $5 3 $5 7 $1 11 -$3 13 -$5 8 2. 9 3 4 10 11 5 12 6 7 $1 13 7 3 $5 14 8 7 15 9 3 10 9 16 1001 995 5 $1 $5 -$1 $3 -$19 $1 $5 -$1 1002 996 27 1003 997 7 3 1004 998 1005 999 9 1006 1,000 17 -$9 1007 1008 Average 8.97 $0.97 true mean of 9. With this number of replications, the average winnings of $0.97 in cell L1008 now provide a reliable basis for concluding that this game will not win you money in the long run. (You can bet that the casino already has used computer simulation to verify this fact in advance.) Example 2: Corrective Maintenance versus Preventive Maintenance The Heavy Duty Company has just purchased a large machine for a new production process. The machine is powered by a motor that occasionally breaks down and requires a major over- haul because of its heavy-duty use. Therefore, the manufacturer of the machine also provides a second standby motor. The two motors are rotated in use, with each one remaining in the machine until it is removed for an overhaul (perhaps because it has just broken down) and replaced by the other one. Given the planned usage of the machine, its manufacturer has provided the company with information about the durability of the motors (the number of days of usage until a breakdown occurs). This information is shown in the first two columns of Table 12.1. The first column lists the number of days the current machine has been in use. For each of these days, the sec- ond column then gives the probability that the breakdown will occur on that day. Since these probabilities are except for days 4, 5, and 6, the breakdown always occurs during the fourth, fifth, or sixth day. The third column provides a straightforward way of assigning random num- bers to correspond to each of these three possibilities. Probability of a Breakdown Corresponding Random Numbers TABLE 12.1 The Probability Distri- bution of Breakdowns for Heavy Duty's Motors, and the Cor- responding Random Numbers Day 1,2,3 4 5 6 7 or more 0 0.25 0.5 0.25 0 0.0000 to 0.2499 0.2500 to 0.7499 0.7500 to 0.9999 I J K L M 1 FIGURE 12.3 This data table improves the reliability of the com- puter simulation recorded in Figure 12.2 by perform- ing 1,000 replications instead of only 14. Data Table for Coin-Flipping Game (1,000 Replications) 2 3 4 5 Play 6 7 1 Number of Flips Winnings 5 $3 3 $5 3 $5 7 $1 11 -$3 13 -$5 8 2. 9 3 4 10 11 5 12 6 7 $1 13 7 3 $5 14 8 7 15 9 3 10 9 16 1001 995 5 $1 $5 -$1 $3 -$19 $1 $5 -$1 1002 996 27 1003 997 7 3 1004 998 1005 999 9 1006 1,000 17 -$9 1007 1008 Average 8.97 $0.97 true mean of 9. With this number of replications, the average winnings of $0.97 in cell L1008 now provide a reliable basis for concluding that this game will not win you money in the long run. (You can bet that the casino already has used computer simulation to verify this fact in advance.) Example 2: Corrective Maintenance versus Preventive Maintenance The Heavy Duty Company has just purchased a large machine for a new production process. The machine is powered by a motor that occasionally breaks down and requires a major over- haul because of its heavy-duty use. Therefore, the manufacturer of the machine also provides a second standby motor. The two motors are rotated in use, with each one remaining in the machine until it is removed for an overhaul (perhaps because it has just broken down) and replaced by the other one. Given the planned usage of the machine, its manufacturer has provided the company with information about the durability of the motors (the number of days of usage until a breakdown occurs). This information is shown in the first two columns of Table 12.1. The first column lists the number of days the current machine has been in use. For each of these days, the sec- ond column then gives the probability that the breakdown will occur on that day. Since these probabilities are except for days 4, 5, and 6, the breakdown always occurs during the fourth, fifth, or sixth day. The third column provides a straightforward way of assigning random num- bers to correspond to each of these three possibilities. Probability of a Breakdown Corresponding Random Numbers TABLE 12.1 The Probability Distri- bution of Breakdowns for Heavy Duty's Motors, and the Cor- responding Random Numbers Day 1,2,3 4 5 6 7 or more 0 0.25 0.5 0.25 0 0.0000 to 0.2499 0.2500 to 0.7499 0.7500 to 0.9999