---
title: "When simulation is appropriate or not"
subject: "Simulation and Modeling"
chapter: 1
key: "semester_8/simulation_and_modeling:simulation-appropriate-not"
source: https://www.bctengineer.com/q/semester_8/simulation_and_modeling/simulation-appropriate-not
site: BCT Engineering
---

# When simulation is appropriate or not

Simulation and Modeling · Chapter 1: Introduction to Simulation

- Asked in: 2072 Ashwin, 2+6 marks
- Video: [Introduction to Simulation and Modeling](https://www.youtube.com/watch?v=9KdC12vwyqY) — Faisal Concepts
- Answer checked by Claude Opus 5.5 (high effort) on 2026-10-14
- Page: https://www.bctengineer.com/q/semester_8/simulation_and_modeling/simulation-appropriate-not
- Whole chapter: https://www.bctengineer.com/md/semester_8/simulation_and_modeling/chapter-1

## Question

What is simulation and modeling? Explain when simulation is an appropriate and not an appropriate tool.

## Short answer

Modeling builds a simplified representation of a system; simulation runs it over time. Simulation is appropriate for studying complex interactions, testing changes, training, compressing time, or when real tests are risky/costly. It is not appropriate when common sense or analytical formulas suffice, data are unavailable, cost exceeds savings, or time/skill are lacking.

## Answer

#### Simulation and modelling
**Modelling** is the process of building an abstract representation (physical or mathematical) of a system. **Simulation** is the imitation of the operation of that system over time by experimenting with the model, usually on a computer, to understand its behaviour or evaluate alternatives.

#### When simulation is appropriate
- To study and experiment with the internal interactions of a complex system or a subsystem.
- To see the effect of informational, organizational and environmental changes by changing the model and observing results.
- When knowledge gained during model building suggests improvements in the system.
- To find which variables are most important and how they interact.
- To test new designs, layouts or policies before spending money on them.
- To verify analytical solutions.
- To train operators (flight simulators) and to demonstrate a design through animation.
- When time must be compressed or expanded to study a system.
- When the real system is too dangerous, costly or slow to experiment with.

#### When simulation is not appropriate
- When the problem can be solved by common sense.
- When it can be solved analytically (e.g. a simple M/M/1 queue formula).
- When direct experiment on the real system is easier and cheaper.
- When the cost of simulation exceeds the likely savings.
- When resources or time (people, computers, deadline) are not available.
- When data are not available to build, verify and validate the model.
- When not enough time or skill exists to verify and validate the model.
- When managers have unreasonable expectations, such as expecting too much too soon or exact answers from a simulation.
- When the system behaviour is too complex or cannot be defined, for example human behaviour that is hard to model.

## Check yourself

The answer's key points as multiple-choice questions, with the correct option and why.

1. What is the relationship between modelling and simulation?
   A. Modelling builds the abstract representation; simulation experiments with it over time
   B. Simulation builds the representation; modelling runs it
   C. They are the same thing
   D. Modelling is only done on physical hardware
   Answer: A. Modelling is building the representation; simulation is imitating the operation over time by experimenting with the model. (Key point: Modelling vs simulation)

2. In which case is simulation NOT appropriate?
   A. Training pilots with a flight simulator
   B. A simple M/M/1 queue that can be solved by an analytical formula
   C. Testing a new factory layout before building it
   D. Studying a system too dangerous to experiment on
   Answer: B. If a problem can be solved by common sense or an analytical formula, simulation is unnecessary. (Key point: When simulation is not appropriate)

3. Why is simulation inappropriate when data are not available?
   A. Simulation does not use data
   B. Data are only needed for reports
   C. Data are needed to build, verify and validate the model
   D. Missing data make the model exact
   Answer: C. Without data the model cannot be built, verified and validated, so its results cannot be trusted. (Key point: Data and expectations)

## Related in Simulation and Modeling

- [Define simulation; steps of simulation study](https://www.bctengineer.com/question.md?key=semester_8%2Fsimulation_and_modeling%3Asimulation-study-steps) — Simulation and Modeling, chapter 1, asked 5×
- [Java simulation of single server queue](https://www.bctengineer.com/question.md?key=semester_8%2Fsimulation_and_modeling%3Ajava-simulation-single-server) — Simulation and Modeling, chapter 9, asked 5×
- [CPU simulation with example](https://www.bctengineer.com/question.md?key=semester_8%2Fsimulation_and_modeling%3Acpu-simulation-example) — Simulation and Modeling, chapter 10, asked 4×
- [Simulation run statistics](https://www.bctengineer.com/question.md?key=semester_8%2Fsimulation_and_modeling%3Asimulation-run-statistics) — Simulation and Modeling, chapter 8, asked 2×
- [Simulation of computer system serving WWW](https://www.bctengineer.com/question.md?key=semester_8%2Fsimulation_and_modeling%3Acomputer-system-www-request) — Simulation and Modeling, chapter 10, asked 2×
- [Steps of simulation study and advantages](https://www.bctengineer.com/question.md?key=semester_8%2Fsimulation_and_modeling%3Asimulation-steps-advantages) — Simulation and Modeling, chapter 1

## Related in other subjects

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