Reconsider Prob. 22.6-3. You now wish to begin the analysis by performing a short simulation by hand and then applying the regenerative method of statistical analysis when possible.
(a) Starting with four new tubes, simulate the operation of the two alternative policies for 5,000 hours of simulated time. Obtain the needed uniform random numbers as instructed at the beginning of the Problems section.
(b) Use the data from part (a) to make a preliminary comparison of the two alternatives on a cost basis. (c) For the proposed policy, describe an appropriate regeneration point for defining cycles that will permit applying the regenerative method of statistical analysis. Explain why the regenerative method cannot be applied to the current policy.
(d) For the proposed policy, use the regenerative method to obtain a point estimate and 95 percent confidence interval for the steadystate expected cost per hour from the data obtained in part (a).
(e) Write a computer simulation program for the two alternative policies. Then repeat parts (a), (b), and (d) on the computer, with 100 cycles for the proposed policy and 55,000 hours of simulated time (including a warm-up period of 5,000 hours) for the current policy
Prob. 22.6-3
The Avery Co. factory has been having a maintenance problem with the control panel for one of its production processes. This control panel contains four identical electromechanical relays that have been the cause of the trouble. The problem is that the relays fail fairly frequently, thereby forcing the control panel (and the production process it controls) to be shut down while a replacement is made. The current practice is to replace the relays only when they fail. However, a proposal has been made to replace all four relays whenever any one of them fails to reduce the frequency with which the control panel must be shut down. The objective is to compare these two alternatives on a cost basis. The pertinent data are the following. For each relay, the operating time until failure has approximately a uniform distribution from 1,000 to 2,000 hours. The control panel must be shut down for 1 hour to replace one relay or for 2 hours to replace all four relays. The total cost associated with shutting down the control panel and replacing relays is $1,000 per hour plus $200 for each new relay. Use simulation on a spreadsheet to evaluate and compare the two alternatives on a cost basis. In each case, perform 1,000 iterations (where the end of each iteration coincides with the end of a shutdown of the control panel) and generate the various available results.