RAPTOR Studio

An open-source reliability block diagram (RBD) simulator for Windows, macOS and Linux. Draw a diagram of parts that can fail and be repaired, run thousands of simulated futures, and read availability, reliability, maintenance, spares and cost numbers like an engineer, then find out which part to spend money on.

RAPTOR Studio carries on from Raptor 7, the simulator written at ARINC and released as open source by Booz Allen Hamilton. Its simulation engine was ported from Raptor 7's own source and checked, event by event, against what Raptor 7 itself writes, so the numbers are the ones reliability engineers already trust. Models made in Raptor 7 open here. Around that engine is a new application, a command line, and an AI-assistant server.

Like Raptor 7, it is released under the Booz Allen Public License (BAPL). Anyone may use, modify and share it, but a commercial entity may use it only for its internal business and for services to government and non-profit organisations, and nobody may charge a fee for it without Booz Allen Hamilton's permission. See Licence & credits.

Why use it

• Numbers you can rely on. The detailed event logs and report files of hundreds of models captured from Raptor 7 are reproduced character for character, including its random-number generator. Where Raptor 7 does something surprising, the port reproduces it and says so.

• It tells you what to fix, not just how you are doing. Weak-link analysis, single-point-failure lists and importance measures (Birnbaum, RAW, RRW and Vesely–Fussell, see below) rank the parts of your system by how much they matter, and colour the diagram to match.

• Built for speed. Runs split across your processor cores, and the engine, layout, validation and file loading have been tuned so that models with hundreds or thousands of blocks are practical to build, open and run. We expect it to be faster than Raptor 7 on most models, particularly large ones and batches on several cores. raptor estimate times a few runs and tells you how long a full batch will take before you start it.

• Runs anywhere. One installer or pip install, on Windows, macOS and Linux.

• Scriptable. Everything the application does is also a command (raptor run, sweep, compare, diff, estimate, validate, spf, fev, step, extract, render and more) with machine-readable results. It fits in a continuous-integration job, a Jupyter notebook or a shell loop.

• Usable from an AI assistant. An MCP server with 64 tools lets an assistant build, edit, validate, simulate, compare and explain models, run long batches in the background, and draw the diagram. The MCP server reference covers install, client setup and every tool, resource and prompt. The recording below is a real run of those tools (the numbers are the engine's; the assistant's narration is scripted):

  

• A model file you can read and diff. .rbds is one JSON document with friendly field names, and raptor diff (or File ▸ Differences) says in words what changed between two versions of a model. .rbd files open and save exactly as before.

• Documentation that ships with it. Break It Before It Breaks, a 23-chapter tutorial book with a model for each chapter that opens from the page, a field-by-field reference manual, and a formulas page. F1 opens the right section.

Which part matters most? Importance measures

Availability says how good the system is. Importance says which block to improve. Switch on Run ▸ Analysis ▸ Importance measures (or raptor run --importance both, or importance on the MCP simulate tool) and RAPTOR Studio re-simulates the model with each block in turn made unable to fail, and with it dead, then ranks every block by how much the system moves. You get:

• Birnbaum, RAW (risk achievement worth), RRW (risk reduction worth) and Vesely–Fussell importance, the IEC 61078 Annex D measures, each with its sampling error so you can tell a real ranking from noise;
• an Importance tab in the results, and a Show on Canvas colouring that paints the most influential blocks red and badges each block with its rank;
• an up-front time estimate that includes the extra batches, so a long analysis never surprises you.

The equations are on the Formulas page, and the tutorial's weak-link chapter works through an example.

What is new compared with Raptor 7

Install

Windows / macOS / Linux (recommended for non-technical users)

Grab the installer for your platform from the Releases page:

Verify the checksums against SHA256SUMS.txt in the same release. The installers carry the desktop application only; the raptor command line and the MCP server come with the pip package (below).

macOS note (unsigned build): Gatekeeper will ask for confirmation. Right-click RAPTOR Studio → Open → Open, or run xattr -cr "/Applications/RAPTOR Studio.app" once in Terminal.

Windows note (unsigned build): SmartScreen may show "Windows protected your PC" — click More info → Run anyway.

PyPI (technical users, and for the MCP server)

pip install raptor-studio              # the application and command line
pip install "raptor-studio[mcp]"       # plus the MCP server for AI assistants

or, isolated from your system Python:

pipx install "raptor-studio[mcp]"

For the assistant server alone, uvx raptor-studio-mcp --workspace ~/raptor-models runs it without an install step.

Then run raptor-studio for the application, raptor --help for the command line, or raptor-studio-mcp for the assistant server. Requirements: Python 3.12+. The PDF export uses WeasyPrint, which needs system Pango — Linux: sudo apt install libpango-1.0-0 libpangocairo-1.0-0, macOS: brew install pango. The Windows/macOS installers bundle it.

A first run from the command line

raptor validate model.rbd            # errors and warnings
raptor run model.rbd -n 200 -j 4     # 200 runs on 4 processes, summary on screen
raptor run model.rbd -n 500 --importance both   # also rank the blocks by importance
raptor run model.rbd -r events -r end-of-run -o results/   # also write Raptor 7-format report files
raptor sweep model.rbd --vary "block:Pump A.repair_params[0]=12,24,48" --metric Availability
raptor diff before.rbds after.rbds   # what changed between two versions

raptor help lists every command and topic.

Learning materials

The app opens on a start page with a blank model, worked examples (from the guide's basics to a hospital's emergency power, a water-treatment works, a data centre and a phased airliner flight) and links to the built-in documentation, which the Help ribbon tab also opens:

• User Guide — the tutorial book Break It Before It Breaks: 23 chapters, from a three-block lantern to a tuned data centre, with companion .rbds models you can open straight from the book (the opsmodel buttons).
• Reference Manual — field-by-field reference; F1 jumps to the section for the focused panel or dialog.
• Formulas — every metric, the importance measures and the distribution table as equations, on one page.
• Keyboard shortcuts — docs/KEYBOARD_SHORTCUTS.md, also under Help. Press Alt in the app to show a key tip on every ribbon button.
• AI assistant — docs/MCP.md and the book's last chapter.
• File format — docs/RBDS_FORMAT.md describes the .rbds JSON format.

IEC 61078

IEC 61078:2016 defines reliability block diagrams and the methods used to evaluate them. RAPTOR Studio uses the same vocabulary (series, parallel, m-out-of-n, sub-RBDs, repaired and non-repaired blocks) but evaluates a model by Monte Carlo simulation, which lets it include repair, spares, phases, dependencies and limited resources. It is not a certified implementation of the standard, and this is a capability statement, not a compliance claim.

In short: series, parallel, mixed and m-out-of-n structures, repaired and non-repaired blocks and sub-RBDs are supported, and the standard's worked examples are regression-tested against the simulator. The Annex D importance measures are estimated by re-simulation (see above). Minimal cut/tie sets, Boolean and BDD evaluation, analytical availability and PFD_avg, repeated blocks, non-coherent blocks and PAND/SEQ/CCF gates are not implemented. The full clause-by-clause table is in docs/IEC61078.md; MCP clients can read it with read_doc('iec61078').

How the fidelity is checked

The engine is tested against files written by Raptor 7 itself, captured while driving it under Wine and, for the hardest cases, while following its scheduler with a debugger.

• tests/golden/ holds over 200 models with Raptor 7's output for each. Their event logs, report files and random-draw logs are compared exactly, and a scan of the captured event logs currently finds none of the recorded runs different.
• The engine code names the Raptor 7 procedure each part reproduces, and the design of each part is described in docs/engine-design/.
• More than 7,500 automated tests run on every change, including the application's own windows and dialogs and an adversarial test of the MCP server.

Development

pip install -e ".[dev,mcp]"   # `mcp` extra needed by the MCP server tests
pytest                        # unit + fast integration; add -m slow for UI sweeps

CONTRIBUTING.md describes the test tiers and the conventions for changing the engine. The docs render with Ruby asciidoctor: new_docs/tools/render_docs.sh (see new_docs/README.md).

Repository layout

Roadmap

Directions under consideration — ideas, not commitments, in no fixed order:

• A live view of an assistant's work. Watch the model an AI assistant is building through the MCP server in a second, read-only window, redrawn on each edit.
• More Raptor 7 parity checks. Keep comparing results with the original on new model shapes and rarely used options.
• Further solution methods. Analytical and fault-tree solvers beside the simulation, for quick answers and cross-checks; minimal cut/tie sets and BDD evaluation; importance of whole hierarchies; common-cause and dynamic gates.
• Richer maintenance and logistics. Crews, shifts and supply chains that the model can express directly.
• Uncertainty and sensitivity analysis. Ask which input matters most, and how sure the answer is.

Licence & credits

RAPTOR was originally created at ARINC (Chuck Carter, Steve Brown, Tony Malerich, Elizabeth Grimes) and released as open source by Booz Allen Hamilton — many thanks to BAH. RAPTOR-derived material stays under the Booz Allen Public License v1.0 (LICENSE); new code in this port is licensed under the Apache License 2.0 (LICENSES/Apache-2.0.txt). See NOTICE.md for attribution details.