Module 5 capstone
A Discrete-Event Queueing Simulation
Specify, implement, verify, and report a discrete-event simulation of a queueing system.
§ Project brief
The Module 5 capstone is a complete discrete-event simulation of a queueing system. You will specify the system using the four-concept vocabulary (entities, events, resources, queues), implement an event calendar and clock-advancement mechanism, run the simulation with replication, apply warm-up removal, and report performance measures with confidence intervals.
Optionally, you may also build a Markov-chain model of the same system or a related one, and compare the two approaches. This is encouraged but not required.
Output analysis is not optional
A discrete-event simulation without warm-up removal and replication produces a number of uncertain provenance. The output analysis is the deliverable.
§ Learning outcomes addressed
This capstone assesses
- Specify a discrete-event system in the four-concept vocabulary.
- Implement an event calendar and clock-advancement mechanism.
- Verify against an analytical result where available.
- Identify the warm-up period and discard it.
- Run independent replications and construct confidence intervals.
- Report performance measures with appropriate output analysis.
§ Suggested systems
M/M/1 queue
Single server, Poisson arrivals, exponential service. Analytical results available for verification.
M/M/c queue
Multi-server system. Analytical results available for utilisation and mean wait.
Priority queue
Two or three priority classes. No closed-form solution; verification uses conservation and comparison to a simple case.
Two-stage service
Entities pass through two sequential stages. Queue length at stage 2 depends on the output of stage 1.
§ Deliverables
| Deliverable | Weight | What it should contain |
|---|---|---|
| System specification | 15% | Entities, events, resources, queues, arrival process, service process, routing, termination. |
| Event calendar implementation | 20% | Working event calendar and clock advancement. Hand trace of the first few events. |
| Verification | 15% | Conservation check (arrivals = departures at termination). Comparison against analytical M/M/1 or M/M/c where applicable. |
| Warm-up analysis | 15% | Running-mean plot. Identification of warm-up period. Sensitivity to the chosen period. |
| Replication and confidence intervals | 20% | 20+ replications. Mean, SE, and 95% CI for the primary performance measure. |
| Technical report | 15% | Three to five pages including specification, implementation, verification, output analysis, and limitations. |
§ Milestones
- Specify the system Four-concept vocabulary, full specification. Two hours.
- Implement the event calendar Priority queue, clock advancement, event handlers. Four hours.
- Hand-trace the first few events Compare to a spreadsheet run. Two hours.
- Verify conservation and analytical agreement Arrival/departure count; comparison to M/M/1 if applicable. Two hours.
- Run the warm-up study Plot the running mean; choose W. One hour.
- Run replications 20+ replications with independent seeds; compute mean, SE, CI. Two hours.
- Write the report Three to five pages. One hour.
§ Rubric
| Criterion | Excellent | Satisfactory | Needs work |
|---|---|---|---|
| Specification | Every element stated; disciplines and routing justified. | Every element stated, but justifications thin. | Elements missing or vague. |
| Implementation | Event calendar correct; hand trace matches spreadsheet. | Event calendar correct; hand trace approximate. | Hand trace missing or does not match. |
| Verification | Conservation check passes; analytical agreement within CI. | Conservation check passes; analytical agreement approximate. | Verification not performed. |
| Warm-up | Warm-up identified from running-mean plot; sensitivity shown. | Warm-up identified but not verified. | No warm-up removal. |
| Replication | 20+ replications; CI reported and interpreted. | 10–20 replications; CI reported. | Fewer than 10 replications or no CI. |
§ Common pitfalls
Watch for these
- Scheduling events in the past. If a scheduled time precedes the current clock, the simulation is broken.
- Not removing warm-up. The initial transient biases congestion-related measures downward.
- Using the same seed for all replications. Replications must be independent.
- Reporting the point estimate without the CI. The CI is part of the result.
- Confusing simulation precision with model validity. A narrow CI does not imply a correct model.
§ Submission
What to submit
- A single ZIP archive named
M5-capstone-yourid.zip. - The archive contains the specification, the simulation code or spreadsheet, the hand trace, the verification evidence, the warm-up study, the replication results, and the technical report.
- Submit through the course LMS before the deadline listed on the course schedule.