VIPET

VIPET (Visual and Interactive Performance Evaluation Tool) is a cross-platform desktop application featuring rich and intuitive graphical user interface for creating, simulating, and analyzing queuing networks.

• Visual network editor — draw sources, service centers, sinks and connections on a canvas; edit every property through dialogs. Open and closed networks are detected automatically.
• Analytical solvers — Jackson networks (open) and Gordon–Newell networks (closed), with state probabilities and the full derivation rendered as LaTeX formulas.
• Discrete-event simulation — automatic or guided (step-by-step) runs, multiple independent replications, confidence intervals, warm-up discarding and a choice of random generators.
• What-if analysis — sweep one variable (service or inter-arrival distribution, number of servers, number of jobs in the network) over a range and chart its effect on every performance measure.
• Performance measures — utilization, throughput, queue length, number of jobs, queue waiting time and response time, per service center and for the network as a whole, as table or bar chart.
• Import / export — networks as JSON; results as CSV, XLSX, XLS or JSON; raw simulation samples as XLSX; canvas screenshots as images.
• Modeling primitives — service/arrival distributions (exponential, Erlang, hyperexponential, uniform, deterministic, Pareto), queue disciplines (FIFO, LIFO, SIRO) and routing strategies (probabilistic, random, round-robin).
• Localization — English and Serbian, switchable at runtime from Settings → Language.

Download the latest release for your platform:

Installers bundle their own Java runtime — no JDK is required to run VIPET.

Requires JDK 21 (JavaFX is pulled in by Gradle). No local Gradle installation is needed.

On Linux, macOS, Git Bash, and PowerShell, run ./gradlew. On Windows Command Prompt, run gradlew.

Example networks ship with the application in src/main/resources/dev/askov/vipet/networks/ — open/ for Jackson, closed/ for Gordon–Newell. None of them are loaded at startup: open the JSON files with File → Open, or preload them with --networks, which addresses them as classpath resources.

Two configuration sources are read at startup: the command line, and src/main/resources/application.properties. The properties file is applied last, so every key it defines overrides the corresponding command-line option. Comment a key out there to make the matching option take effect. Startup networks are the exception — the two sources are concatenated rather than overridden, so --networks always works.

Besides the window, language and startup networks, this file holds settings with no command-line equivalent:

Out of the box VIPET starts maximized in Serbian with a single empty network: networks= is blank, so nothing is preloaded. Set it to a comma-separated list of resource paths to open networks on every launch.

jpackage builds an installer for the platform it runs on, so each artifact is produced on its own runner. Pushing a v* tag triggers release.yml, which runs CI on Linux, macOS and Windows, builds the .msi, .deb and .AppImage, and publishes a GitHub release using relnotes/<tag>.md as the release body.

src/main/java/dev/askov/vipet/
├── core/              # solvers and simulation engine, free of UI code
│   ├── analyzer/      #   Jackson and Gordon–Newell analyzers
│   ├── simulator/     #   discrete-event simulator, sample generation and analysis
│   └── performancemeasures/
├── mvc/               # JavaFX layer: models, views, controllers
├── serialization/     # JSON / CSV / Excel importers and exporters
├── configuration/     # CLI arguments and application.properties
└── localization/      # resource-bundle management
src/main/resources/
├── dev/askov/vipet/   # FXML, CSS, images, example networks
└── i18n/              # messages.properties (en), messages_sr.properties (sr)

Build and packaging settings live in gradle.properties (app.*, java.version, javafx.version); dependency versions live in gradle/libs.versions.toml.

• Formatting — the build uses Spotless with googleJavaFormat. Run gradlew spotlessApply before committing; gradlew build fails on violations.
• Logs — development runs write to ./logs/; installed builds write to %LOCALAPPDATA%\VIPET\logs\ (Windows), ~/Library/Logs/VIPET/ (macOS) or ~/.vipet/logs/ (Linux).
• Tests — JUnit 5, covering the analyzers, the simulator and JSON network import. They touch JavaFX classes, so on headless Linux they need Xvfb, as CI does.

Contributions are very welcome — there is so much still to add here, and there is room for ideas of every size. Bug reports, fixes, new features, documentation, translations and plain questions all help. Open an issue or send a pull request; if you are unsure whether something fits, open an issue first and let's talk it through. Don't be shy about picking up something big.

If VIPET is useful to you, please ⭐ star the repository — it helps other people find the project.

Licensed under the GNU General Public License v3.0. Third-party license texts are in licenses/.