Operations Management, 11e (Heizer/Render)
Module F Simulation
Section 1 What is Simulation?
1) Simulation has numerous applications in modern business, but few of these are in the area of
operations.
2) The idea behind simulation is threefold: (1) to imitate a real-world situation mathematically, (2) then to
study its properties and operating characteristics, and (3) finally to draw conclusions and make action
decisions based on the results of the simulation.
3) Simulation may be capable of producing a more appropriate answer to a complex problem than can be
obtained from a mathematical model.
4) Virtually all large-scale simulations take place on computers, but small simulations can be conducted
by hand.
5) Simulation is the attempt to duplicate the features, appearance, and characteristics of a real system,
usually by means of a computerized model.
6) Which of the following statements regarding simulation is TRUE?
A) Large-scale simulation models are virtually all handled by computer.
B) Simulation has numerous areas of application in operations.
C) Simulation attempts to duplicate a real system.
D) The process of simulation involves seven steps.
E) All of these are true.
7) The seven steps in the use of simulation include all EXCEPT which of the following?
A) Define the problem.
B) Construct a numerical model.
C) Introduce important variables associated with the problem.
D) Find the optimal solution.
E) Run the experiment.
8) Which of the following is an idea behind simulation?
A) to imitate a real-world situation mathematically
B) study the properties and operating characteristics
C) draw conclusions and make decisions based on the results
D) both A and B
E) A, B, and C are all ideas behind simulation.
9) Which of the following is TRUE regarding simulation?
A) Small problems can be done by hand.
B) Most simulations are computerized.
C) Real-world complications can be included in simulation models.
D) Simulation is most suitable where standard analytical models are too complex.
E) All of the above are true.
10) ________ is the attempt to duplicate the features, appearance, and characteristics of a real system,
usually via a computerized model.
11) Define simulation.
12) Identify five applications of simulation.
13) State the three-fold idea behind simulation.
14) Identify the seven steps involved in using simulation.
Section 2 Advantages and Disadvantages of Simulation
1) One effective use of simulation is to study problems for which the mathematical models of operations
management are not realistic enough.
2) Simulation allows managers to test the effects of major policy decisions on real-life systems without
disturbing the real system.
3) Simulation provides optimal solutions to problems.
4) Similar to mathematical and analytical models, simulation is restricted to using the standard
probability distributions.
5) Despite the powerful simulation software available today, good simulation models can take a long
time to develop.
6) Simulation models that are based on the generation of random numbers may fail to give the same
solution in repeated use to any particular problem.
7) A simulation model is designed to arrive at a single specific numerical answer to a given problem.
8) Simulation can use any probability distribution that the user defines.
9) Which of the following is NOT a disadvantage of simulation?
A) time compression
B) good simulation models can take a long time to develop
C) repetitive approach
D) all input must be user generated
E) All of these are disadvantages to simulation.
10) Which of the following are advantages of simulation?
I. time compression
II. “what-if?” questions are possible
III. flexibility
IV. repetitive approach
V. input must be user generated
A) I, III, V
B) I, II, V
C) II, III, IV, V
D) I, II, IV, V
E) I, II, III
11) Which of the following is TRUE regarding the use of simulation?
A) It is always very easy to build a simulation model.
B) It may interfere with real-world systems.
C) It always yields optimal solutions.
D) It allows time-compression in testing major policy decisions.
E) Few constraints, if any, have to be considered.
12) Simulation is used for several reasons, including which of the following?
A) Model development is a fast process.
B) The models can usually be solved by hand.
C) The models are usually simple.
D) It can handle large and complex real-world problems.
E) It always generates optimal solutions.
13) One of the advantages of simulation is that:
A) managers must generate all of the conditions and constraints for solutions that they want to examine.
B) it always generates a more accurate solution than a mathematical solution would.
C) the policy changes may be tried without disturbing the real-life system.
D) model development is less time consuming than for mathematical models.
E) model solutions are transferable to a wide variety of problems.
14) One of the disadvantages of simulation is that it:
A) does not allow for very complex problem solutions.
B) is not very flexible.
C) is a repetitive approach that may produce different solutions in different runs.
D) is very limited in the type of probability distributions that can be used.
E) interferes with the production systems while the program is being run.
15) The effects of operations management policies over many months or years can be obtained by
computer simulation in a short time. What is this phenomenon called?
A) time suppression
B) time suspension
C) time compression
D) time inversion
E) time conversion
16) One of the disadvantages of simulation is that it:
A) does not allow for very complex problem solutions.
B) is not very flexible.
C) may be very time-consuming to develop.
D) is very limited in the type of probability distributions that can be used.
E) interferes with the production system while the program is being run.
17) One of the disadvantages of simulation is that it:
A) does not allow for very complex problem solutions.
B) produces solutions and inferences that are not usually transferable to other problems.
C) time compression may occur.
D) is very limited in the type of probability distributions that can be used.
E) interferes with the production system while the program is being run.
18) One of the advantages of simulation is that:
A) real-world complications can be included that most OM models cannot permit.
B) it always generates a more accurate solution than a mathematical model does.
C) it is a repetitive approach that may produce different solutions in repeated runs.
D) model development is less time consuming than for mathematical models.
E) model solutions are transferable to a wide variety of problems.
19) “Time compression” and the ability to pose “what-if?” questions are elements of:
A) setting up a probability distribution for important variables.
B) the disadvantages of simulation.
C) physical simulations but not mathematical simulations.
D) the advantages of simulation.
E) the broad threefold idea of simulation.
20) The effects of OM policies over many months or years can be obtained by computer simulation in a
short time. This phenomenon is referred to as ________.
21) What are the advantages and disadvantages of simulation models?
22) Explain what is meant by the concept of “time compression” in simulation modeling.
Section 3 Monte Carlo Simulation
1) By starting random number intervals at 01, not 00, the top of each range is the cumulative probability.
2) A simulation is “Monte Carlo” when the elements of a system being simulated exhibit chance in their
behavior.
3) Random number intervals are based on cumulative probability distributions.
4) The Las Vegas method is a simulation technique that uses random elements when chance exists in their
behavior.
5) Setting up a probability distribution, building a cumulative probability distribution, and generating
random numbers are:
A) necessary when the underlying probability distribution is normal.
B) three of the five steps in Monte Carlo simulation.
C) elements of physical simulation but not mathematical simulation.
D) the elements of the threefold idea behind simulation.
E) advantages of simulation.
6) Which of the following is NOT a step in running a Monte Carlo simulation?
A) setting up a probability distribution for important variables
B) building a cumulative probability distribution for each variable
C) establishing an interval of random numbers for each variable
D) generating random numbers
E) All of the above are steps in running a Monte Carlo simulation.
7) From a portion of a probability distribution, you read that P(demand = 0) is 0.05 and P(demand = 1) is
0.10. The cumulative probability for demand = 1 would be which of the following?
A) 0.05
B) 0.075
C) 0.10
D) 0.15
E) 0.005
8) From a portion of a probability distribution, you read that P(demand = 1) is 0.05, P(demand = 2) is 0.15,
and P(demand = 3) is .20. The cumulative probability for demand = 3 would be which of the following?
A) 0.133
B) 0.200
C) 0.400
D) 0.600
E) Cannot be determined from the information given.
9) From a portion of a probability distribution, you read that P(demand = 0) is 0.05, P(demand = 1) is 0.10,
and P(demand = 2) is 0.20. What are the two-digit random number intervals for this distribution
beginning with 01?
A) 01 through 05, 01 through 10, and 01 through 20
B) 00 through 04, 05 through 14, and 15 through 34
C) 01 through 05, 06 through 15, and 16 through 35
D) 00 through 04, 00 through 09, and 00 through 19
E) 01 through 06, 07 through 16, and 17 through 36
10) From a portion of a probability distribution, you read that P(demand = 0) is 0.25, and P(demand = 1) is
0.30. What are the random number intervals for this distribution beginning with 01?
A) 01 through 25, and 26 through 30
B) 01 through 25, and 01 through 30
C) 01 through 25, and 26 through 55
D) 00 through 25, and 26 through 55
E) 00 through 25, and 26 through 30
11) A distribution of service times at a waiting line indicates that service takes 6 minutes 30 percent of the
time, 7 minutes 40 percent of the time, 8 minutes 20 percent of the time, and 9 minutes 10 percent of the
time. In preparing this distribution for Monte Carlo analysis, the service time of 8 minutes would be
represented by what random number range?
A) 20 through 40
B) 21 through 40
C) 70 through 90
D) 71 through 90
E) 01 through 20
12) A distribution of service times at a waiting line shows that service takes 6 minutes 30 percent of the
time, 7 minutes 40 percent of the time, 8 minutes 20 percent of the time, and 9 minutes 10 percent of the
time. This distribution has been prepared for Monte Carlo analysis. The first two random numbers drawn
are 53 and 74. The simulated service times are ________ minutes, then ________ minutes.
A) 6; 7
B) 7; 7
C) 7; 8
D) 8; 9
E) Cannot determine because no service time probability is that large.
13) A distribution of service times at a waiting line indicates that service takes 12 minutes 30 percent of
the time and 14 minutes 70 percent of the time. In preparing this distribution for Monte Carlo analysis,
the service time 13 minutes would be represented by what random number range?
A) 00 through 29
B) 01 through 30
C) 30 through 99
D) 31 through 00
E) None of these; 13 minutes is not a possible outcome.
14) A distribution of service times at a waiting line indicates that service takes 12 minutes 30 percent of
the time and 14 minutes 70 percent of the time. This distribution has been prepared for Monte Carlo
analysis. The first four random numbers drawn are 07, 60, 77, and 49. What is the average service time of
this simulation?
A) 12 minutes
B) 13 minutes
C) 13.5 minutes
D) 14 minutes
E) 54 minutes
15) A distribution of lead times in an inventory problem indicates that lead time was 1 day 20 percent of
the time, 2 days 30 percent of the time, 3 days 30 percent of the time, and 4 days 20 percent of the time.
This distribution has been prepared for Monte Carlo analysis. The first four random numbers drawn are
06, 63, 57, and 02. What is the average lead time of this simulation?
A) 1.75 days
B) 2 days
C) 3 days
D) 3.5 days
E) 8 days