Week5 - Module 4: Placeholder Flashcards
Order the following Simulation Study Steps:
- Objectives and Planning
- Data Collection
- Coding
- Model Validation
- Model Verification
- Problem Formulation
- Run Experiements
- Model Building
- Output Analysis
- Experimental Design
Order the following Simulation Study Steps:
- Problem Formulation
- Objectives and Planning
- Model Building
- Data Collection
- Coding
- Model Verification
- Model Validation
- Experimental Design
- Run Experiements
- Output Analysis
Definition:
A Collection of entities (people, machines, etc.) that interact together to accomplish a goal.
A system
Definition:
An abstract representation of a system, usually containing math/logical relationship describing the system in terms of states, entities, sets, events, etc
A model
Definition:
A set of variables that contains enough information to describe the system.
System State:
A set of variables that contains enough information to describe the system. Think of the state as a “snapshot” of the system.
________ can be permanent (like a
machine) or temporary (e.g.,
customers), and can have various
properties or _________ (e.g., priority of
a customer or average speed of a
server).
Entities can be permanent (like a
machine) or temporary (e.g.,
customers), and can have various
properties or attributes (e.g., priority of
a customer or average speed of a
server).
A ____ (or queue) is an ordered list of
associated entities (for instance, a
linked list, or a line of people).
A list (or queue) is an ordered list of
associated entities (for instance, a
linked list, or a line of people).
An _____ is a point in time at which the system state changes (and which can’t be predicted with certainty beforehand).
An event is a point in time at which the system state changes (and which can’t be predicted with certainty beforehand).
Examples: an arrival event, a
departure event, a machine
breakdown event.
“Event” technically means the time
that a thing happens, but loosely
refers to “what” happens (an
arrival).
Definition:
A duration of time of specified length (aka an
unconditional wait).
An **activity** is a duration of time of specified length (aka an unconditional wait).
Examples include:
- exponential customer interarrival times
- constant service times
We can explicitly generate those
events, so they are “specified”.
A __________ _____ is a duration of
time of unspecified length.
E.g., a customer waiting time — we
don’t know that directly. In fact, we
just know arrival and service times
and will use those to reverse-
engineer the waiting times.
A conditional wait is a duration of
time of unspecified length.
E.g., a customer waiting time — we
don’t know that directly. In fact, we
just know arrival and service times
and will use those to reverse-
engineer the waiting times.
The _________ _____ is a variable
whose value represents simulated
time (which doesn’t equal real time).
The simulation clock is a variable
whose value represents simulated
time (which doesn’t equal real time).
Time-Advance Mechanisms = how the clock moves
Name two Ways:
The simulation clock always moves forward (never goes back in time).
Two ways:
- Fixed-Increment Time Advance
- Next-Event Time Advance
The clock is initialized at 0. All known future event times are determined and placed in the future events list (FEL), ordered by time.
Next-Event Time Advance: The clock is initialized at 0. All known future event times are determined and placed in the future events list (FEL), ordered by time.
Any time there’s an event, the simulation may update the
chronological order of the FEL’s events. Name 4 events.
Any time there’s an event, the simulation may update the
chronological order of the FEL’s events. Name 4 events.
- inserting new events,
- deleting events,
- moving them around, or
- doing nothing.
