---
title: "Define simulation; steps of simulation study"
subject: "Simulation and Modeling"
chapter: 1
key: "semester_8/simulation_and_modeling:simulation-study-steps"
source: https://www.bctengineer.com/q/semester_8/simulation_and_modeling/simulation-study-steps
site: BCT Engineering
---

# Define simulation; steps of simulation study

Simulation and Modeling · Chapter 1: Introduction to Simulation

- Asked in: 2074 Bhadra, 2+6 marks; 2071 Bhadra, 2+6 marks; 2070 Bhadra, 2+6 marks; 2072 Magh, 8 marks; 2070 Magh, 8 marks (asked 5 times)
- Video: [Steps and Phases in Simulation for EXAMS !!  Simulation and Modeling](https://www.youtube.com/watch?v=TYUOELsuTDI) — FocusUs
- 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-study-steps
- Whole chapter: https://www.bctengineer.com/md/semester_8/simulation_and_modeling/chapter-1

## Question

What is simulation? Explain the steps involved in a simulation study (with flowchart).

## Short answer

Simulation is imitating a real system's operation over time using a computer model. The study involves problem formulation, objective setting, conceptual modeling, data collection, translation, verification, validation, experimental design, production runs, analysis, documentation, and implementation, iteratively refining the model.

## Answer

#### What is simulation?
Simulation is the imitation of the operation of a real-world process or system over time. We build a model of the system, run it on a computer, and observe its behaviour to draw conclusions about the real system, without building or disturbing the real one. Example: simulating customer arrivals and service at a bank counter to decide how many tellers are needed.

#### Steps in a simulation study
1. **Problem formulation.** State the problem clearly. If the client states it, the analyst checks that it is understood; if the analyst states it, the client must agree with it.
2. **Setting objectives and overall project plan.** Decide the questions the simulation must answer and whether simulation is the right tool. Plan the people, cost, time and the alternative systems to study.
3. **Model conceptualization.** Build the abstract model of the system: its entities, attributes, activities and the logic between them. Start simple and add detail only as needed. The client should take part.
4. **Data collection.** Collect input data (arrival times, service times, failure rates) and fit probability distributions. This runs in parallel with model building because it takes a long time.
5. **Model translation.** Code the model in a general language (C, Java, Python) or a simulation language/package (GPSS, Arena, Simulink).
6. **Verification.** Check that the program works as the conceptual model intends (debugging, tracing, step-by-step runs). "Is the model built right?"
7. **Validation.** Check that the model is an accurate representation of the real system by comparing its output with real data. Calibrate and repeat until accuracy is acceptable. "Is the right model built?"
8. **Experimental design.** Decide the alternatives to run: run length, warm-up period, number of replications, initial conditions.
9. **Production runs and analysis.** Run the experiments and estimate performance measures with confidence intervals.
10. **More runs?** Decide from the analysis whether additional runs or design changes are needed. If yes, return to step 8.
11. **Documentation and reporting.** Write program documentation (for future use and modification) and a progress/final report with results and recommendations.
12. **Implementation.** The client uses the findings. Success depends on how well the earlier steps were done and how involved the client was.

#### Flowchart
```text
 Problem formulation
        |
        v
 Objectives and project plan
        |
        v
 Model conceptualization <---> Data collection
        |
        v
 Model translation
        |
        v
 Verified? --No--> (back to translation)
        | Yes
        v
 Validated? --No--> (back to conceptualization/data)
        | Yes
        v
 Experimental design
        |
        v
 Production runs and analysis
        |
        v
 More runs? --Yes--> (back to experimental design)
        | No
        v
 Documentation and reporting
        |
        v
 Implementation
```

Verification and validation are repeated whenever the model changes, so the process is iterative rather than strictly sequential.

## Check yourself

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

1. Which statement best defines simulation?
   A. Solving a system's equations exactly with algebra
   B. Imitating the operation of a real system over time using a model
   C. Building the real system and measuring it
   D. Collecting data about a system without a model
   Answer: B. Simulation is the imitation of a real process or system over time by running a model, so the real system is not built or disturbed. (Key point: Definition of simulation)

2. A student checks that the program behaves exactly as the conceptual model intends by tracing and debugging. Which step is this?
   A. Validation
   B. Experimental design
   C. Verification
   D. Model conceptualization
   Answer: C. Verification asks 'is the model built right?' (program matches the conceptual model). Validation compares output with the real system. (Key point: Verification vs validation)

3. How is a model validated?
   A. By comparing its output with real-system data and calibrating until accuracy is acceptable
   B. By running it for more replications
   C. By rewriting it in a simulation language
   D. By checking the code for syntax errors
   Answer: A. Validation checks that the model represents the real system accurately, by comparing output with real data and calibrating repeatedly. (Key point: Validation)

4. After production runs and analysis, the analyst finds more runs are needed. Where does the study return to?
   A. Problem formulation
   B. Model translation
   C. Data collection
   D. Experimental design
   Answer: D. If more runs or design changes are needed, the study returns to experimental design (step 8) to choose run length, replications and so on. (Key point: Iterative nature / more runs)

## Related in Simulation and Modeling

- [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

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