Exam 12: Introduction to Simulation Using Risk Solver Platform

As the number of replicates in a simulation increases the width of a confidence interval computed from the simulation results will

Which of the following probability distributions are associated with discrete outcomes?

An auto parts store wants to simulate its inventory system for engine oil. The company has collected data on the shipping time for oil and the daily demand for cases of oil. A case of oil generates a $10 profit. Customers can buy oil at any auto parts store so there are no backorders (the company loses the sale and profit). The company orders 30 cases whenever the inventory position falls below the reorder point of 15 cases. Orders are placed at the beginning of the day and delivered at the beginning of the day so the oil is available on the arrival day. An average service level of 99% is desired. The following spreadsheets have been developed for this problem. The company has simulated 2 weeks of operation for their inventory system. The current level of on-hand inventory is 25 units and no orders are pending. -Using the information in Exhibit 12.3, what formula should go in cell G9 to compute inventory position?

An auto parts store wants to simulate its inventory system for engine oil. The company has collected data on the shipping time for oil and the daily demand for cases of oil. A case of oil generates a $10 profit. Customers can buy oil at any auto parts store so there are no backorders (the company loses the sale and profit). The company orders 30 cases whenever the inventory position falls below the reorder point of 15 cases. Orders are placed at the beginning of the day and delivered at the beginning of the day so the oil is available on the arrival day. An average service level of 99% is desired. The following spreadsheets have been developed for this problem. The company has simulated 2 weeks of operation for their inventory system. The current level of on-hand inventory is 25 units and no orders are pending. -Using the information in Exhibit 12.3, what formula should go in cell J8 to determine the arrival date for an order?

A simulation model was replicated 100 times yielding a mean of 82.59 with variance of 17.66. Of the 100 replications, 11 replications yielded an outcome over a value of 100. What is the 95% confidence interval on the proportion of simulations whose outcomes exceeded a value of 100?

The manager of a Washington, DC sightseeing tour company is concerned about overbooking for one of his bus tours. The bus has 15 seats but sometimes there are empty seats. His records show that about 20% of ticket holders do not show up for their tour. Tickets cost $10 and are non-refundable. If the manager overbooks the tour and more than 15 passengers show up, some of them will be bumped to a later tour. This bumping costs the company $25 in various expenses to keep the customer happy until the next tour. The manager wants to see what happens to profits if 18 reservations are accepted. -Using the information in Exhibit 12.4, what Risk Solver Platform (RSP) function should be used in cell C10 to determine the number of Passengers to Board?

An auto parts store wants to simulate its inventory system for engine oil. The company has collected data on the shipping time for oil and the daily demand for cases of oil. A case of oil generates a $10 profit. Customers can buy oil at any auto parts store so there are no backorders (the company loses the sale and profit). The company orders 30 cases whenever the inventory position falls below the reorder point of 15 cases. Orders are placed at the beginning of the day and delivered at the beginning of the day so the oil is available on the arrival day. An average service level of 99% is desired. The following spreadsheets have been developed for this problem. The company has simulated 2 weeks of operation for their inventory system. The current level of on-hand inventory is 25 units and no orders are pending. -Using the information in Exhibit 12.3, what formula should go in cell C9 and copied to C10:C21 of the MODEL sheet to compute units received?

How should one determine which RNGs to employ in a spreadsheet simulation model?

The owner of Fix-a-dent Auto Repair wants to study the growth of his business using simulation. He is interested in simulating the number of damaged cars and the amount of damage to the cars each month. He currently repairs 100 cars per month and feels the change in number of cars can vary uniformly between a decrease of as much as 3% and an increase of up to 5% (average change of 1%). The dollar value of the damage to the cars is a normally distributed random variable with a mean of $3,000 and a standard deviation of $500. The average repair bill has been increasing steadily over the years and the owner expects the mean repair bill will increase by 1% per month. A spreadsheet model to simulate the problem has been run 300 times. A part of the simulation statistics output from Risk Solver Platform (RSP)and a spreadsheet for computing confidence intervals follows. -Using the information in Exhibit 12.2, what formula should go in cell B8 of the Confidence Intervals spreadsheet to compute the upper limit on a 95% confidence interval for the true population mean?

The owner of Sal's Italian Restaurant wants to study the growth of his business using simulation. He is interested in simulating the number of customers and the amount ordered by customers each month. He currently serves 1000 customers per month and feels this can vary uniformly between a decrease of as much as 5% and an increase of up to 9%. The bill for each customer is a normally distributed random variable with a mean of $20 and a standard deviation of $5. The average order has been increasing steadily over the years and the owner expects the mean order will increase by 2% per month. You have created the following spreadsheet to simulate the problem. -The spreadsheet model for Sal, from Exhibit 12.5, has been run 300 times to produce the following output. What is the best case scenario for Sal based on this output?

What is the correct Risk Solver Platform (RSP) function for generating random numbers from the following distribution on the number of children in families (assume a reference to the current worksheet).

If chance or uncertainty is present in a system then there is an element of ____ in the decision-making problem.

The owner of Sal's Italian Restaurant wants to study the growth of his business using simulation. He is interested in simulating the number of customers and the amount ordered by customers each month. He currently serves 1000 customers per month and feels this can vary uniformly between a decrease of as much as 5% and an increase of up to 9%. The bill for each customer is a normally distributed random variable with a mean of $20 and a standard deviation of $5. The average order has been increasing steadily over the years and the owner expects the mean order will increase by 2% per month. You have created the following spreadsheet to simulate the problem. -Using the information in Exhibit 12.5 and the Risk Solver Platform (RSP), what formulas should go in cells B8:D21 of the spreadsheet?

If a spreadsheet simulation user has a probability distribution that may assume 1 of 5 values with nearly equal probability, this user has what type of distribution?

What function should be used for generating random numbers between a and b from a symmetric triangular distribution when the most likely value is (a + b)/2?

University Florists makes bouquets from a variety of materials. The Daily Special Bouquet is priced at $20. The florist assembles this bouquet each day from a variety of low cost flowers he buys from his flower supplier. The actual cost of flowers ranges uniformly from $2 to $7, with all intermediate values being equally likely. The florist (who studied management science many years ago) knows that the time to assemble a bouquet is normally distributed with a mean time of 5 minutes and standard deviation of 1 minute. This will be the time required for all of the Daily Special Bouquets for that day. The florist values his labor time at $10 per hour. Sales are normally distributed with a mean of 10 bouquets per day with a standard deviation of 1 bouquet. What formulas should go in cells B8:B14 to simulate daily profits for the store?

Simulation is used to

Which of the following probability distributions are associated with continuous outcomes?

Which of the following distributions can be generated by Risk Solver Platform (RSP)?

An auto parts store wants to simulate its inventory system for engine oil. The company has collected data on the shipping time for oil and the daily demand for cases of oil. A case of oil generates a $10 profit. Customers can buy oil at any auto parts store so there are no backorders (the company loses the sale and profit). The company orders 30 cases whenever the inventory position falls below the reorder point of 15 cases. Orders are placed at the beginning of the day and delivered at the beginning of the day so the oil is available on the arrival day. An average service level of 99% is desired. The following spreadsheets have been developed for this problem. The company has simulated 2 weeks of operation for their inventory system. The current level of on-hand inventory is 25 units and no orders are pending. -Using the information in Exhibit 12.3, what formula should go in cell H3 to compute the service level?