ISYE 6644 Final Exam (NEW 2025/2026 Update)
Simulation and Modeling for Engineering and
Science
Georgia Institute of Technology
SECTION A: TRUE/FALSE QUESTIONS (Questions 1-40)
1. TRUE or FALSE? You can pre-assign a service time as an attribute before you actually get to the server
that you'll be using.
ANSWER: TRUE
Rationale: In Arena, attributes can be assigned to entities prior to seizing a resource. This allows pre-
specification of service times based on entity characteristics before the resource is even acquired .
2. TRUE or FALSE? If you have a Create module generating one-at-a-time customer arrivals, then it is not
possible to use a different Create module with 4-at-a-time customer arrivals.
ANSWER: FALSE
Rationale: Arena allows multiple Create modules with different arrival patterns. You can have one
module generating single arrivals and another generating batch arrivals of 4 customers simultaneously .
3. TRUE or FALSE? Fake customers can be used to schedule machine breakdowns, keep track of which
time period the simulation is currently in, and carry out other duties not associated with actual
customers.
,ANSWER: TRUE
Rationale: "Fake" or "dummy" entities are a common Arena technique for scheduling events, updating
variables, and managing simulation control logic without representing physical customers .
4. TRUE or FALSE? The Process module is found in the Advanced Process panel of Arena.
ANSWER: FALSE
Rationale: The Process module is in the Basic Process panel. The Advanced Process panel contains
modules like Seize, Delay, Release, and others that provide more flexibility .
5. TRUE or FALSE? You can schedule failures to occur after a random number of customers have used a
resource or after a random amount of time has passed.
ANSWER: TRUE
Rationale: Arena's failure scheduling allows failures based on either time-based or count-based triggers,
giving flexibility in modeling resource breakdowns .
6. TRUE or FALSE? You are only allowed to schedule one type of failure for a particular resource.
ANSWER: FALSE
Rationale: Resources can have multiple failure schedules defined, each with different failure rules, repair
times, and downtimes .
7. TRUE or FALSE? The Queue block can connect up to the Seize module from the Advanced Process
template.
ANSWER: FALSE
,Rationale: The Queue block from the Blocks template is designed to work with other Blocks template
modules, not directly with the Seize module from the Advanced Process template .
8. TRUE or FALSE? Resource sets, counter sets, entity type sets, and entity picture sets are all allowed in
Arena.
ANSWER: TRUE
Rationale: Arena supports multiple set types including Resource sets, Counter sets, Entity Type sets, and
Entity Picture sets for organizing simulation elements .
9. TRUE or FALSE? It is possible for the resource Joey to be a member of three different resource sets.
ANSWER: TRUE
Rationale: A single resource can belong to multiple sets simultaneously, allowing flexible resource
grouping for different purposes .
10. TRUE or FALSE? The customer arrival pattern for the Call Center demo changes over the day and is
therefore modeled as a nonhomogeneous Poisson process.
ANSWER: TRUE
Rationale: The Call Center demo uses time-varying arrival rates to model changing customer demand
throughout the day, characteristic of a nonhomogeneous Poisson process .
11. TRUE or FALSE? All of the Tech Support servers for the Call Center are equally skilled and have the
same concurrent work schedules.
ANSWER: FALSE
, Rationale: The Call Center model includes servers with different skill sets and work schedules to reflect
real-world call center operations .
12. TRUE or FALSE? In the Call Center demo, fake customers are used to update a variable that keeps
track of the period of the day.
ANSWER: TRUE
Rationale: Fake entities are used to update period variables that control which time-of-day arrival rates
are active .
13. TRUE or FALSE? In the inventory demo, fake customers are used to initiate a periodic inventory
review.
ANSWER: TRUE
Rationale: The inventory model uses fake entities to trigger periodic review events, implementing the
inventory policy logic .
14. TRUE or FALSE? Suppose that X₁, X₂,... is a stationary stochastic process with covariance function Rₖ =
Cov(X₁, X₁₊ₖ), for k=0,1,... Then the variance of the sample mean can be represented as Var(X) = (1/n)[R₀
+ 2Σ(1-k/n)Rₖ].
ANSWER: TRUE
Rationale: This is the standard formula for the variance of the sample mean of a stationary process,
accounting for autocovariances .
15. TRUE or FALSE? If f(x,y) = cxy for all 0 < x < 1 and 1 < y < 2, where c is whatever value makes this
integrate to 1, then X and Y are independent random variables.
Simulation and Modeling for Engineering and
Science
Georgia Institute of Technology
SECTION A: TRUE/FALSE QUESTIONS (Questions 1-40)
1. TRUE or FALSE? You can pre-assign a service time as an attribute before you actually get to the server
that you'll be using.
ANSWER: TRUE
Rationale: In Arena, attributes can be assigned to entities prior to seizing a resource. This allows pre-
specification of service times based on entity characteristics before the resource is even acquired .
2. TRUE or FALSE? If you have a Create module generating one-at-a-time customer arrivals, then it is not
possible to use a different Create module with 4-at-a-time customer arrivals.
ANSWER: FALSE
Rationale: Arena allows multiple Create modules with different arrival patterns. You can have one
module generating single arrivals and another generating batch arrivals of 4 customers simultaneously .
3. TRUE or FALSE? Fake customers can be used to schedule machine breakdowns, keep track of which
time period the simulation is currently in, and carry out other duties not associated with actual
customers.
,ANSWER: TRUE
Rationale: "Fake" or "dummy" entities are a common Arena technique for scheduling events, updating
variables, and managing simulation control logic without representing physical customers .
4. TRUE or FALSE? The Process module is found in the Advanced Process panel of Arena.
ANSWER: FALSE
Rationale: The Process module is in the Basic Process panel. The Advanced Process panel contains
modules like Seize, Delay, Release, and others that provide more flexibility .
5. TRUE or FALSE? You can schedule failures to occur after a random number of customers have used a
resource or after a random amount of time has passed.
ANSWER: TRUE
Rationale: Arena's failure scheduling allows failures based on either time-based or count-based triggers,
giving flexibility in modeling resource breakdowns .
6. TRUE or FALSE? You are only allowed to schedule one type of failure for a particular resource.
ANSWER: FALSE
Rationale: Resources can have multiple failure schedules defined, each with different failure rules, repair
times, and downtimes .
7. TRUE or FALSE? The Queue block can connect up to the Seize module from the Advanced Process
template.
ANSWER: FALSE
,Rationale: The Queue block from the Blocks template is designed to work with other Blocks template
modules, not directly with the Seize module from the Advanced Process template .
8. TRUE or FALSE? Resource sets, counter sets, entity type sets, and entity picture sets are all allowed in
Arena.
ANSWER: TRUE
Rationale: Arena supports multiple set types including Resource sets, Counter sets, Entity Type sets, and
Entity Picture sets for organizing simulation elements .
9. TRUE or FALSE? It is possible for the resource Joey to be a member of three different resource sets.
ANSWER: TRUE
Rationale: A single resource can belong to multiple sets simultaneously, allowing flexible resource
grouping for different purposes .
10. TRUE or FALSE? The customer arrival pattern for the Call Center demo changes over the day and is
therefore modeled as a nonhomogeneous Poisson process.
ANSWER: TRUE
Rationale: The Call Center demo uses time-varying arrival rates to model changing customer demand
throughout the day, characteristic of a nonhomogeneous Poisson process .
11. TRUE or FALSE? All of the Tech Support servers for the Call Center are equally skilled and have the
same concurrent work schedules.
ANSWER: FALSE
, Rationale: The Call Center model includes servers with different skill sets and work schedules to reflect
real-world call center operations .
12. TRUE or FALSE? In the Call Center demo, fake customers are used to update a variable that keeps
track of the period of the day.
ANSWER: TRUE
Rationale: Fake entities are used to update period variables that control which time-of-day arrival rates
are active .
13. TRUE or FALSE? In the inventory demo, fake customers are used to initiate a periodic inventory
review.
ANSWER: TRUE
Rationale: The inventory model uses fake entities to trigger periodic review events, implementing the
inventory policy logic .
14. TRUE or FALSE? Suppose that X₁, X₂,... is a stationary stochastic process with covariance function Rₖ =
Cov(X₁, X₁₊ₖ), for k=0,1,... Then the variance of the sample mean can be represented as Var(X) = (1/n)[R₀
+ 2Σ(1-k/n)Rₖ].
ANSWER: TRUE
Rationale: This is the standard formula for the variance of the sample mean of a stationary process,
accounting for autocovariances .
15. TRUE or FALSE? If f(x,y) = cxy for all 0 < x < 1 and 1 < y < 2, where c is whatever value makes this
integrate to 1, then X and Y are independent random variables.
