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OpenProcess

Process mining, Petri nets and workflows in one open app.
Every algorithm is there to read, every result can be reproduced, every step can be taught.
Pure Python and Qt. No Java, no Wine, no separate simulator to install.

Latest release PyPI Tests and builds MIT licence

⬇ Download for macOS, Windows or Linux · no Python needed · or pip install openprocess[app] · install guide

Drawing a WF-net and checking its soundness

OpenProcess Studio is the workbench; OpenProcess Learn is the teaching mode built on it. Together they bring under one roof what usually takes several tools (and, until version 0.7, went by the name CPNpy):

What you can do Instead of
Petri nets & WF-nets Draw nets the way the lectures do. Get a soundness verdict with a counterexample for every violation, and replay it in the token game. Also: behavioural properties, P- and T-invariants, the footprint matrix, the reachability graph, PNML import and export. WoPeD, ProM, pen and paper
Process mining Import XES or CSV logs, or type textbook logs like [<a,b,c>^3, <a,c>^2]. Filter them, explore variants, the dotted chart and the process map. Discover models (α-algorithm, Inductive Miner, Heuristics Miner, state-based regions). Check conformance (token replay, alignments, precision…) and compare logs. ProM, Disco
Coloured Petri nets Open, edit and save CPN Tools models (.cpn), hierarchical ones included. Step through or simulate them, compute the state space, and export a simulation as an event log to mine. CPN Tools / CPN IDE
Workflows Boxes on a canvas: a log, a miner, a fitness check, a comparison, a sweep over a setting, a prediction pipeline. Click a box to see its result, how it got there (the α-algorithm's eight steps, the replay per variant), its code and its settings. Change a setting and only what follows runs again. Saved as a .cpnflow file with everything needed to get the same numbers back. Your own algorithm is one Python function in a boxes/ folder. RapidProM
Learn A mode of its own for worksheets, built on the app: answer in boxes on the sheet (sets, markings, matrices, cuts and trees, alignments, a net in the editor or a workflow on the canvas beside it) and press Check. Most answers are checked automatically, often against answers worked out from the given log or net. Packs are plain Markdown, can be exams with a clock and points, and a past exam imports as a skeleton pack. Demo exercises included. Answer sheets, a notes app and guesswork
Folders Open a folder such as Week 2: every log and net in it is listed in the sidebar, with its subfolders. The folder and the app stay in step both ways: new nets and edits are saved into it as you go, and changes made in Finder show up by themselves. Finder windows and File ▸ Open every time

Contents


Install

OpenProcess runs on macOS, Windows and Linux. Download the app, or run it from source if you want to change the code.

Download the app

No Python needed. Take the file for your system from the latest release:

System File Then
macOS OpenProcess-…-macOS-arm64.dmg (Apple silicon) or …-macOS-x64.dmg (Intel) Open it and drag OpenProcess onto Applications.
Windows OpenProcess-…-Windows-x64.zip Unzip it anywhere and start OpenProcess\OpenProcess.exe. For a desktop shortcut: right-click OpenProcess.exe ▸ Send to ▸ Desktop.
Linux OpenProcess-…-Linux-x64.tar.gz tar xzf OpenProcess-*.tar.gz, then ./OpenProcess/install-desktop-entry.sh to add it to the applications menu and the desktop.

The apps are not signed with a paid developer certificate, so the system asks once, the first time you start one:

  • macOS says Apple could not check it. Click Done, then open System Settings ▸ Privacy & Security and click Open Anyway next to OpenProcess. (Or in Terminal: xattr -dr com.apple.quarantine /Applications/OpenProcess.app.)
  • Windows shows Windows protected your PC. Click More info, then Run anyway.

Later versions install themselves: the app says when one is out, or ask with Help ▸ Check for Updates….

With pip

For a script, a notebook, a box of your own, or CI, OpenProcess is a normal Python package with no required dependencies:

pip install openprocess            # the engine: process mining, Petri nets, workflows, Learn
pip install "openprocess[app]"     # also the desktop app: then `openprocess studio`
pip install "openprocess[app,science]"   # and the pandas, SciPy and matplotlib boxes

Code written for CPNpy keeps working: import cpnpy is openprocess under its old name (with a one-line warning), so existing boxes and exercise packs run unchanged.

From source

You need Python 3.10 or newer, with Qt through PySide6. The easiest way to set it up is a conda environment called openprocess, defined in environment.yml.

1. Get conda (once)

Install Miniforge, a small conda that uses the conda-forge packages.

System How
macOS brew install miniforge, then conda init zsh and open a new terminal. (Or the installer from the Miniforge page.)
Windows Download and run Miniforge3-Windows-x86_64.exe from the Miniforge page. Then use the Miniforge Prompt from the Start menu (or run conda init powershell once in it to use conda in PowerShell).
Linux curl -LO https://github.com/conda-forge/miniforge/releases/latest/download/Miniforge3-Linux-x86_64.sh, then bash Miniforge3-Linux-x86_64.sh and open a new terminal.

2. Get the code and create the environment

The same commands on every system (Terminal on macOS and Linux, Miniforge Prompt or PowerShell on Windows):

git clone https://github.com/s4mstruthers/openprocess.git
cd OpenProcess
conda env create -f environment.yml       # Python 3.12, PySide6, pytest, OpenProcess itself
conda activate openprocess

No git? Use Code ▸ Download ZIP on GitHub, unzip it and cd into the folder.

3. Start the app

openprocess-studio

python -m openprocess.gui.studio does the same. After pulling changes that touch environment.yml or pyproject.toml, run conda env update -f environment.yml --prune.

Without conda (plain Python and pip)

With Python 3.10 or newer from python.org or your package manager, make a virtual environment in the project folder:

System Commands
macOS / Linux python3 -m venv .venv
source .venv/bin/activate
Windows (PowerShell) py -m venv .venv
.venv\Scripts\Activate.ps1
Windows (cmd) py -m venv .venv
.venv\Scripts\activate.bat

Then, on every system:

pip install -e ".[app,dev]"
openprocess-studio

If PowerShell refuses to run Activate.ps1, allow local scripts once with Set-ExecutionPolicy -Scope CurrentUser RemoteSigned.

Linux: Qt needs a few system libraries that desktop installs usually have. If the app does not start and the error mentions the "xcb" platform plugin or libEGL.so.1, install them, e.g. on Ubuntu/Debian: sudo apt install libxcb-cursor0 libxkbcommon-x11-0 libegl1.

Keyboard shortcuts follow the system: ⌘ on a Mac, Ctrl on Windows and Linux (see Keyboard shortcuts).


Quick start

Work in a folder (recommended): File ▸ Open Folder… (⌥⌘O / Ctrl+Alt+O) and pick a folder such as Week 2, or drop the folder onto the window. See Folders.

Check whether a WF-net is sound

  1. File ▸ New Petri Net (⌘N / Ctrl+N).
  2. Pick Place and click on the canvas. Type a name and press Return (or click elsewhere to keep the suggested name), and the tool switches back to Select on its own. Do the same with Transition.
  3. Pick Arc and drag from a place to a transition, or the other way round. Drag again from the same node to add more arcs.
  4. Open the Analysis tab on the right. It shows whether the net is a WF-net, whether it is sound, its behavioural properties and its footprint. Everything updates after each edit.
  5. If it isn't sound, press Show ▶ next to a finding. The net switches to Step through and fires the counterexample, so you can see the problem marking.

To try this without drawing, use File ▸ Open Example Petri Net ▸ Order handling (unsound — try Analysis).

Mine a log

  1. ✎ Log from notation… (⌘L / Ctrl+L) and type [<a,b,c,d>^3, <a,c,b,d>^2, <a,e,d>] (pasting [⟨a,b,c,d⟩³, …] from the book works too), or open a .xes / .csv file.
  2. Look through the tabs: Overview, Variants, Cases, Dotted chart, Process map, Footprint. Filter… keeps part of the log as a new log.
  3. On the Discover tab, pick an algorithm: the model and how it was derived update straight away. Open as model → adds the result to the sidebar (under MODELS, or UNSAVED in a folder until you press Keep to save it there).
  4. On the model's Conformance tab, choose a log and press Check conformance.

Simulate a coloured net

File ▸ Open Coloured Petri Net… (⇧⌘O / Ctrl+Shift+O), then Step through or Simulate.


Folders: one per week

Keep each week's material in a folder (the logs from the course, the nets you draw) and open it: File ▸ Open Folder… (⌥⌘O / Ctrl+Alt+O), or drag the folder onto the window. The sidebar and the folder always match: what you see in OpenProcess is what is in Finder (or Explorer), and the other way round.

The folder Week 2 in the sidebar, with its subfolders, one net open and the others listed

In the sidebar

  • Every event log and net in the folder is listed, open or not. Files that are not open yet are lighter: click one to open it. Closing a file (✕ or ⌘W) puts it back in that state; it stays in the folder.
  • Folders shows the folder as it is on disk, with collapsible subfolders (folders first, then files, by name). By kind groups the files into event logs, Petri nets and coloured nets instead. The choice, and which subfolders are open, is remembered for each folder.
  • Organise from the app: right-click for New Folder…, Rename…, Show in Finder and Move to Bin (recoverable from the Bin; never a hard delete). Drag files onto a subfolder to move them on disk. An open file that is moved or renamed stays open, unsaved edits included. Drag a file out of the sidebar to Finder to copy it there.
  • Subfolders are listed up to three levels deep and 500 files (a row says so when there are more), with hidden files and tools' folders (__pycache__, .git, …) skipped, as Finder does.

From the app to the folder

  • New nets are files from the start: New Petri Net creates Untitled 1.pnml (a coloured net, Untitled 1.cpn) in the folder. Rename the net (double-click its name) and the file is renamed with it.
  • Edits are saved as you go (autosave): a second after you stop editing, and when you switch to another file or quit. There is no "edited" dot, and undo still works. Turn it off with File ▸ Autosave. File ▸ Revert to Saved… goes back to the file as it was when you opened it. A .cpn model made in CPN Tools is not autosaved (OpenProcess would rewrite it in its own writer) until you save it once yourself with ⌘S.
  • Logs you make are files too: a log typed in notation is saved as <name>.log.txt (still in notation), a filtered log as <log> (filtered).xes next to the log it came from, and a CPN simulation's log as <model> simulation.xes.
  • A discovered model stays in the UNSAVED group until you press Keep, so trying algorithms does not fill the folder. Keep saves it as PNML next to its log.
  • Saving writes a temporary file and then swaps it in, so a crash never leaves a half-written file.

From the folder to the app

  • Files added, renamed or deleted in Finder (or by any other app, a git pull, iCloud) appear and disappear by themselves, in about half a second on macOS.
  • An open file changed on disk (a .xes exported again from ProM, a .pnml edited in WoPeD) is reloaded by itself. If it also has edits in OpenProcess that are not saved yet, a bar above the page asks: Reload (lose my edits) or Keep Mine. OpenProcess's own saves are recognised and never reload.
  • An open file moved or renamed in Finder, within the folder, stays open and follows the file to its new place, unsaved edits included.
  • An open file deleted, or moved out of the folder, stays open, shown in italics with a missing bar: Save As… to keep it. It is not quietly recreated.
  • If a net cannot be saved automatically (a read-only folder, a full disk), a bar says so once and the net is saved with ⌘S again, with its "edited" dot, until saving works.
  • A file still being copied in is not read half-way.
  • With iCloud Drive's Optimise Mac Storage, files that are only in iCloud are listed with a ☁: click one to download and open it.

Files from elsewhere

Opening a file from outside the folder (File ▸ Open…, Open Recent, or dropping it on the window) asks whether to copy it into the folder (the default: the original stays where it is), move it in, or open it from where it is. Tick Always do this to stop asking for that folder, or set the default in Settings. A file with the same name already in the folder is never overwritten silently: Keep Both (Wilma 50 2.xes) or Replace (the old one goes to the Bin). Dropping a file onto a subfolder in the sidebar puts it there. Files opened where they are appear under OTHER FILES.

Coming back

  • What you had open comes back the next time you open the folder, and the app reopens the last folder at launch. This is kept in a small hidden file, .openprocess, in the folder, with paths relative to the folder, so it keeps working if you move or sync the folder. Delete it to start fresh.
  • Switch with File ▸ Open Recent Folder, the buttons on the welcome page, or the ⋯ menu next to the folder's name, which also has Show in Finder, New Folder… and Close Folder.

Opening a folder closes the files that are not in it (it asks first about unsaved changes). Without a folder, the app works with loose files as before: nothing is autosaved or created on disk until you save it, and the files you had open come back at launch (File ▸ Reopen Files at Launch turns that off).

A tip for the course: one folder per week inside your course folder, e.g. Process Mining/Week 2, with the week's logs and the nets you make.


Petri nets and WF-nets

Nets drawn as in the lectures and the book:

  • Places are circles with black tokens inside, drawn as dots up to 5 and as a number above that.
  • Transitions are boxes with their name inside. A silent (τ) transition is a black bar.
  • Arc weights above 1 are written on the arc.
  • Names go inside the places and transitions, which grow to fit them. Tick Names outside in the toolbar to put them underneath instead; you can then drag each name where you want it. Both are saved in the PNML file.

Select anything to edit it in the Element tab: a place's name and tokens, whether a transition is silent, an arc's weight and direction.

Analysis tab

Every property is defined mathematically in docs/definitions.md. In the app, hover over a property (the ones marked ⓘ) to see its definition filled in for your net — with your place names, and when it fails, the marking and firing sequence that break it. Click it to keep the definition open and follow links to the definitions it builds on; Help ▸ Definitions lists them all.

The definition of option to complete, filled in for the order-handling net

  • WF-net: exactly one source place i, one sink place o, and every node on a path between them.

  • Soundness:

    • (i) option to complete;
    • (ii) proper completion;
    • (iii) no dead transitions.

    Every violation comes with a firing sequence as its counterexample, and Show ▶ plays it on the net.

  • Short-circuited net N̄: the net plus a transition t* from o back to i. By the soundness theorem, the net is sound iff (N̄, [i]) is live and bounded; both are shown, with the transition that can't fire again and the marking where that happens. Safe and deadlock-free are shown too. Open the short-circuited net draws it.

  • Structure: free-choice, well-structured (no PT- or TP-handles in N̄, with the two paths of a handle spelled out) and S-coverable, plus the start and end rule: a quick check for transitions that need i or o together with another place.

  • Invariants: the P-invariants (weighted token counts that never change, e.g. start + c1 + c3 + end = 1) and the T-invariants (of N̄ for a WF-net), and whether they cover the net. Covered by P-invariants means bounded from any marking; a transition in no T-invariant of N̄ proves the WF-net unsound. Incidence matrix… shows the matrix they come from.

  • Behavioural properties of the net as drawn: bounded, safe, deadlock-free, dead transitions, live, reversible. A WF-net always stops in [o], so that dead marking is marked as expected.

  • Footprint: the → ← ‖ # matrix of the net's behaviour, to compare with a log's footprint (α-algorithm, footprint conformance).

  • Reachability graph…, or a coverability graph with ω when the net is unbounded.

  • Conformance with a log… opens the net as a model next to your logs, for token replay and alignments.

The counterexample, replayed The footprint of the net
Counterexample in the token game Footprint of a sound net

Also on the Petri net page

  • Step through / Simulate: the token game, fired by hand or at random. With Trace ticked, every fired transition shows its step numbers and the arcs the tokens used light up, the latest step strongest.
  • Generate event log…: plays the net out many times and opens the traces as a log.
  • Saving: nets are saved as PNML (ProM, WoPeD and PM4Py read it), or as .cpn. Save As names the net after its file. With a folder open, a new net is Untitled 1.pnml in the folder from the start and is saved as you edit (Folders); without one, it is called Untitled 1 until you save it.
  • Renaming: double-click the net's name in the sidebar, or its title above the canvas. The file is renamed with it, in the same folder (an existing file is never overwritten).
  • Opening: a .pnml file opens in this editor. A model you discovered has ✎ Edit a copy to bring it here.

Renaming a transition in place


Process mining

Log overview Dotted chart
Overview Dotted chart
  • Logs:
    • XES, XES.GZ and CSV (you map the columns);
    • the course's notation, e.g. [<a,b,c,d>^3, <a,e,d>] (or ⟨a,b⟩³ as in the book);
    • XES, CSV and notation export.
  • Edit… a log after opening it: as notation (a log you typed comes back exactly as you typed it, so you can change it), or case by case — add, delete, duplicate and reorder events and cases, edit activities, timestamps and resources, rename or remove an activity everywhere. The edit is saved to the log's file; XES and CSV logs keep their other attributes.
  • Filter (as in ProM and Disco): keep cases in a time frame, cases that start or end with chosen activities, only the events of chosen activities (or the cases that do or do not contain them), cases of a certain length, and the most frequent variants. A preview shows what is left; the result opens as a new log.
  • Explore: overview figures, variants, cases, a ProM-style dotted chart, a process map (directly-follows graph with frequency or performance), and the footprint matrix.
    • Dotted chart axes: actual time, time since case start, % of case duration, or logical order (in the log, or within the case).
    • Time unit (Auto, or seconds up to years) and a grid step you can type in.
    • Colour and shape by any attribute. The default palette can be changed per value: right-click a value in the legend and pick its colour.
  • Discover:
    • α-algorithm, which shows its eight steps;
    • Inductive Miner and IMf;
    • Heuristics Miner, as a dependency graph or as a Petri net: which forks are AND and which XOR is learned from the log (a causal net, whose bindings are listed). Like in ProM, such a net fits its log but is not always sound;
    • state-based regions, two-phase: the log becomes a transition system through a state function you choose (the prefix, postfix or both of each event; as a set, multiset or sequence; over the last k events or all of them), and its minimal regions become the places. The derivation shows the transition system (pick a trace to light up the states it passes through), the regions, GER and minimal pre- and post-regions of every event, state separation and forward closure, and whether the net's reachability graph is isomorphic to the transition system.
  • Transition systems (File ▸ New Transition System…, or a ts.txt file): type one as s0 -a-> s1, s0 -b-> s2 and get the same region analysis and synthesis. Is this a region? answers yes or no for any set of states (type it or click the states), and for no names the event and the two transitions that cross it differently.
  • Models:
    • token game;
    • soundness and properties;
    • reachability graph;
    • PNML / PNG / SVG export.
  • Conformance:
    • token-based replay and optimal alignments, both drawn on the model;
    • fitness, precision, generalisation and simplicity;
    • alignments per variant.
  • Compare logs: key figures, activity and variant shares, and linked dotted charts, side by side.
  • Compare nets (File ▸ Compare Nets…): do two nets allow the same complete traces? Silent steps are ignored and transitions matched by label, so layout and place names do not matter. You get the shortest traces that differ, both ways, each replayable in the token game. Exact for bounded nets; for unbounded ones, up to a trace length (and it says so).
Process map Discovering a model
Process map Discover
α-algorithm result Conformance (alignments on the model)
Alpha Conformance
Comparing two logs Linked dotted charts of three boarding strategies
Comparing two logs Linked dotted charts

The app follows the system's light or dark appearance:

Dark mode


Learn

OpenProcess Learn is the teaching side of the app, built on top of it: exercise packs with answer boxes that the app checks. Click an exercise folder in the sidebar, Learn ▸ Open Exercise Pack…, or Learn ▸ Open Demo Exercises (it asks where to put a copy, since your answers are saved next to the exercises): the window switches to a view made for working through a pack without distractions, and Exit brings your folder back exactly as it was.

  • The worksheet on the left is the question top to bottom, with an answer box wherever one is needed: yes/no, multiple choice, a set ({a, b}, sets of sets, or pairs like ({a}, {b,d})), a number, a short text, a footprint matrix, a firing sequence (which you can play in the net), a marking or a set of markings, the net as (P, T, F, m₀), an incidence matrix or a reachability graph, the Inductive Miner's cuts, sublogs and process tree, a replay table (p, c, m, r), an alignment, a ranking of models, a prediction of what an algorithm will give, free text, a net to draw in the editor beside it, or a workflow to build on the canvas beside it.
  • Check says whether each answer is right — and when it is not, how far off it is (“2 of your items are right, 1 is missing”, the wrong cells of a matrix, which part of the tuple is off, the shortest traces where your net differs, which you can replay) without giving the answer away. Typed notations show how they are read as you type. Hint and Show answer are there when you want them.
  • The materials on the right are what the exercise gives: the log, the transition system, the given net (to play, not change), your own net, and the Workflow tab. Results that would give answers away — soundness, the footprint, discovered models, regions… — stay hidden until you reveal them.
  • Notes (✎ in the top bar) opens scratch paper under the worksheet for working things out, kept with the exercise.
  • Points and exams. Every answer box is worth points (a partly right answer earns a part), and the overview shows the score so far. A pack can be an exam: a clock in the top bar, no hints or answers, nothing revealed, and the answers locked when the time is up. ⋯ ▸ Export Marks… writes the marks as CSV. A pack can also give every student a variant of its own (a log played out from a net with a seed made from their name).
  • Your work is saved as you go, in the exercise's folder: my answers.json, my answer.pnml for a net, my workflow.cpnflow for a workflow and my notes.md.

Writing a pack (for a course or an exam) is plain Markdown: put an answer block wherever students should answer.

**b.** Give the start activities $T_I$.

```answer
type: set
compute: alpha.T_I
points: 2
hint: Which activities does a trace begin with?
```

compute: works the right answer out from the exercise's own log, net or transition system (α-algorithm steps, the Inductive Miner's cuts, soundness and its conditions, markings and matrices, replay, regions, fitness… and any box of the workflow library: box(alpha_miner).net.transitions), so most answers need not be written by hand. Learn ▸ Writing Exercise Packs (openprocess/learn/exercise-packs.md) lists every box type and computed answer. From a terminal, openprocess exercises check <pack> reports mistakes in a pack before you share it, openprocess exercises marks <pack> prints the marks, openprocess exercises computes lists every compute, and openprocess exercises import exam.txt <pack> (or Learn ▸ Make a Pack from an Exam…) turns a past exam's text into a skeleton pack, one exercise per question with an answer block per part, for you to finish. Exercises written for earlier versions still work: a sheet written in lettered parts (a., b., …) gets a box under each part, with that part of answer.md as its model answer.

The code is openprocess.learn (no Qt: the worksheet format, the notations, the computed answers and the checks) and openprocess.gui.learn (the window).

Coloured Petri nets

A reimplementation of the modelling, simulation and analysis parts of CPN Tools / CPN IDE, including their CPN ML inscription language: colour sets, variables, functions, guards and timed tokens.

  • Edit: places, transitions and arcs, with their inscriptions, guards, time delays and declarations (syntax-highlighted). Undo and redo cover everything.
  • Hierarchy: substitution transitions run their subpages (a port place is the socket place it is assigned to), also several levels deep. Select a substitution transition and press Open subpage to go there.
  • Step through: green transitions are enabled. Click one to fire it, or pick an exact binding in the inspector. Back undoes a step, and Trace highlights the path so far.
  • Simulate: Play (1–60 firings per second) or Fast-forward. The firing history can be exported as an event log and mined straight away.
  • State space: runs in a separate process, so it can be stopped at any moment. It reports dead markings, home markings, liveness and bounds.
  • Rendering: models look the way CPN Tools and CPN IDE draw them (bendpoints, label positions, token bubbles), and they save back to .cpn.
Stepping through a model Editing an arc (handles on every bend)
Step through Arc editing

State space


Working on the canvas

Both editors work the same way. Arcs follow the rules of CPN IDE.

To… Do this
Add a place / transition Pick Place / Transition, click the canvas, type the name, press Return (or just click elsewhere: the name box closes and keeps the name)
Rename Double-click the place or transition, or use the Element tab
Rename a net or log Double-click its name in the sidebar or the title above the canvas. A net named after its file (as every opened or saved net is) renames the file too, in the same folder.
Connect Move the mouse just outside a place or transition and drag the faint arrow that appears onto another node. Or pick Arc and drag from one node to another, or click one node, then the other. Joining two places (or two transitions) is refused, with an explanation. Esc cancels.
Grow a net quickly Drag a node's arrow (or, with Arc, drag from a node) out onto empty canvas: a see-through preview shows what letting go will add — a transition after a place, a place after a transition — joined by an arc. It lines up with nodes it is nearly level with (or lands on the grid). Type its name, or click its arrow and keep going. One undo takes the node and its arc away.
Pan Scroll (two fingers on a trackpad; Shift + wheel goes sideways), drag with the middle mouse button, or hold Space and drag. The canvas goes on in every direction, so there is always room to start a new part beside the net; Fit frames the whole net again. If the net is panned right out of view, a button at the top of the canvas points to it and brings it back.
Zoom ⌘-scroll / Ctrl+scroll or pinch zooms about the pointer; or − % + in the corner
Keep things neat Tick Snap to grid (next to Names outside): new and moved places, transitions and arc bends land on the canvas's dots. Snap All to Grid neatens a net drawn freely: every place, transition and arc bend moves to the nearest dot, and the layout stays yours. Undo puts it back.
Move things Drag them. Nodes snap into line with other nodes (dashed guides show it). Drag on empty canvas to select several.
Bend an arc Press anywhere on the arc and drag: that adds a bend. Drag an existing bend (a small circle) to move it.
Remove a bend Drag it back into line with its neighbours
Slide a straight segment Drag the bar in the middle of a horizontal or vertical segment
Reconnect an arc Drag one of its ends onto another node
Move a label Drag it (names can be dragged once Names outside is ticked)
Delete Select, then Delete or Backspace (⌫)
Undo / redo ⌘Z / ⇧⌘Z (Ctrl+Z / Ctrl+Shift+Z), or ↶ ↷

The tool buttons have icons, and the mouse cursor over the canvas shows the active tool: a plain pointer for Select, a crosshair with a circle, square or arrow for the others.


Keyboard shortcuts

The app shows each shortcut the way your system writes it.

Action macOS Windows / Linux
New Petri net ⌘N Ctrl+N
New coloured Petri net ⇧⌘N Ctrl+Shift+N
Open… ⌘O Ctrl+O
Open folder… ⌥⌘O Ctrl+Alt+O
Open coloured Petri net… ⇧⌘O Ctrl+Shift+O
Log from notation… ⌘L Ctrl+L
Compare logs… ⇧⌘C Ctrl+Shift+C
Save / Save As ⌘S / ⇧⌘S Ctrl+S / Ctrl+Shift+S
Undo / Redo ⌘Z / ⇧⌘Z Ctrl+Z / Ctrl+Shift+Z (or Ctrl+Y)
Delete selection ⌫ Delete or Backspace
Step (fire one random enabled transition) ⌘. Ctrl+.
Zoom in / out / fit / 100 % ⌘+ / ⌘− / ⌘0 / ⌥⌘0 Ctrl++ / Ctrl+− / Ctrl+0 / Ctrl+Alt+0
Zoom with the mouse ⌘-scroll or pinch Ctrl+scroll or pinch
Pan scroll, middle-drag, or Space + drag scroll, middle-drag, or Space + drag
Toggle sidebar ⌥⌘S Ctrl+Alt+S
Settings… ⌘, Ctrl+,
Welcome page ⌘1 Ctrl+1
Export selected… ⌘E Ctrl+E
Close / close all ⌘W / ⇧⌘W Ctrl+W / Ctrl+Shift+W
Cancel drawing an arc Esc Esc

Files

Format Read Write
Event logs: .xes, .xes.gz, .csv ✓ .xes, .xes.gz, .csv
Logs in textbook notation: log.txt, *.log.txt ✓
Transition systems: ts.txt, *.ts.txt (s0 -a-> s1) ✓ ✓
Petri nets: .pnml (with positions, weights, τ, arc bends) ✓ ✓
CPN Tools models: .cpn ✓ ✓
Pictures of nets and charts .png, .svg
Folder state: .openprocess (hidden, in the folder) ✓ ✓

Example files: examples/petri/*.pnml (Petri nets), examples/*.cpn (coloured nets) and tests/data/ (a plane-boarding model and log from the course).


For developers

pytest -q                 # the whole suite, including GUI tests that run offscreen
openprocess --help              # command line: check, simulate, state space, mining

The same commands work on macOS, Windows and Linux. openprocess mine covers the process mining side: stats, filter, discover (α, IM, IMf, heuristics), conform, soundness and invariants; openprocess exercises check, marks, import and computes serve exercise packs. docs/definitions.md is generated from openprocess/mining/definitions.py; after editing a definition, run python -m openprocess.mining.definitions > docs/definitions.md (a test checks it). Likewise docs/references.md — every source OpenProcess's notation and algorithms follow, also in the app under Help ▸ References — is generated from openprocess/references.py with python -m openprocess.references > docs/references.md.

The engines (openprocess.mining, openprocess.ml, openprocess.sim, openprocess.analysis) have no dependencies, so they work in a notebook or a script:

from openprocess.mining import read_xes, inductive_miner
from openprocess.mining.analysis import check_soundness

net = inductive_miner(read_xes("log.xes").simple_log()).net
report = check_soundness(net)
print(report.sound, report.findings)

docs/how-it-works.md covers the architecture, the CPN ML subset, binding search, timed nets, the state space, the file format and the project layout.

Workflows

File ▸ New Workflow opens a workflow that already runs on the first log of your folder (or a typed log): Discover and check (a log, the Inductive Miner, a fitness check), Compare discovery (three miners side by side), Noise sweep (one setting over a range, the scores stacked), Fitness with confidence (bootstrap intervals, a test and a plot; needs the science extra) and Predict the next activity. Or start empty.

  • The page is the canvas. Three buttons in its header: + Add box, Run ▶, and ⋯ for Re-run, Record, Export experiment and Save.
  • + Add box (or a double-click on the canvas) opens every box, by group: the six core groups side by side (Input, Filter, Discover, Check, Compare, Output) and one line for the rest (Science, Predict, Coloured nets, Sweep, your own boxes) with Show all. Type to search them all: "alpha" finds the α-algorithm; Enter adds the first match.
  • Connect by dragging from the dot on the right of a box: while you drag, only the inputs that take that kind of result light up, so a wrong connection cannot be made. Click a wire and press Delete to remove it.
  • Click a box and the side panel appears beside the canvas, on Result (the net, the log's figures, the table, the figure; a log's Result has Open as log › for the dotted chart, process map, footprint, variants and cases). Its other tabs: How (what the box reported: notes, intermediate values, the derivation), Code (the box's few lines and, under them, the actual algorithm it calls: the α-algorithm's eight steps, the Inductive Miner's cuts, with the work each follows and Whole file for the module) and Settings (a control per setting; Sweep a number over a range). ⤢ opens the tab in a window of its own; ✕, or a click on the canvas, puts the panel away.
  • Only what changed runs again. Every box shows a status dot: waiting, running, done, failed (the error is on the Result tab; the rest keeps working), or waiting for your OK.
  • Record shows the workflow as Python and the file with its record; Re-run says what changed since it was saved (an input file, a box file, a seed) before running everything again.
  • Your own boxes: a .py file in the folder's boxes/ subfolder (see below). The app asks once per folder before running them, and reloads a box when its file is saved.
  • Groups: select boxes and press ⌘G to make one box of them, with the connections that reach outside; double-click it to open its own canvas, ⇧⌘G to ungroup. Save as a box in the side panel writes the group to boxes/, so it is listed under Yours and can be used in any workflow.
  • Export experiment (under ⋯) writes a zip with the workflow file and its record, the inputs, your boxes, every result as a file (CSV, PNML, SVG, XES), a requirements.lock and a README that says what was run: supplementary material for a paper, which openprocess run --check can verify.
  • The side panel resizes by dragging the gap beside it; double-click the gap, or View ▸ Reset Workflow Layout, for its default width.

Workflows from Python

Every algorithm is also a box: a Python function with type hints that the app (from 0.7) draws on a canvas. A workflow of boxes runs from Python or from the command line, and its .cpnflow file records what is needed to get the same numbers again: fingerprints of the input files and of the box code, every seed, and the installed packages.

from openprocess.flow import Workflow, Runner, save
from openprocess.flow.boxes.input import open_log
from openprocess.flow.boxes.discover import inductive_miner
from openprocess.flow.boxes.check import check_fit

wf = Workflow("orders")
log = wf.add(open_log, {"file": "orders.xes"})
model = wf.add(inductive_miner, {"noise": 0.2})
fit = wf.add(check_fit)
wf.connect(log, model); wf.connect(model, fit, "model"); wf.connect(log, fit, "log")
run = Runner().run(wf)
print(run.value(fit).metrics)                  # fitness, precision, generalisation, simplicity
print(run.result(model).explanation.steps)     # how the Inductive Miner got there
save(wf, "orders.cpnflow", run)
openprocess run orders.cpnflow --check     # re-run; fails if any result differs from the record
openprocess run orders.cpnflow --sweep noise=0..0.5 step 0.1
openprocess boxes                          # the 47 boxes, with a folder's boxes/
openprocess datasets list                  # the BPI Challenge, Sepsis, ... logs by name

A box of your own is one function in a boxes/ folder:

from openprocess.flow import box, EventLog, TransitionSystem

@box(group="Discover")
def last_two(log: EventLog, representation: str = "multiset") -> TransitionSystem:
    """The last two activities as the state."""
    ...

pip install -e ".[science]" adds the pandas, NumPy, SciPy and matplotlib boxes (describe, bootstrap intervals, tests, plots). Large logs are read into columns rather than objects, so a million events fit in memory. docs/workflows.md has the whole framework: writing a box, the types, the How tab, sweeps, the prediction pipeline, the record and running in CI.

Building the apps. packaging/ turns OpenProcess into a standalone app with PyInstaller. In the environment:

pip install pyinstaller
python packaging/build.py      # → dist/OpenProcess.app or dist/OpenProcess/, plus a .dmg / .zip / .tar.gz

The script also smoke-tests the result. Each system can only build its own app, so the Build apps workflow builds all of them on GitHub: for every pull request (after the test suite passes; not for documentation-only changes) and for every release tag. Download them from the run's page, under Artifacts, or start a build by hand with Run workflow on the Actions tab.

Publishing a release:

  1. Add a section for the new version at the top of CHANGELOG.md (## 0.4.0, then a few bullet points). Write it for the people using the app: it becomes the text of the release on GitHub, and the app shows it when it offers the update.

  2. Set __version__ in openprocess/__init__.py to the same version and merge both into main. It is the only place the version is written: pyproject.toml, the download names and the app's update check all read it from there.

  3. Tag that commit with the same version and push the tag:

    git pull
    git tag v0.4.0
    git push origin v0.4.0
    

About five minutes later the Releases page has the macOS (Apple silicon and Intel), Windows and Linux apps. The build refuses a tag that does not match __version__, or a version with no section in CHANGELOG.md.

Updates. Each time it opens, the app checks the latest release on GitHub (Settings turns that off). If there is a newer version, a slim bar at the top of the window says so, without getting in the way: What's New shows the changelog of every version you don't have yet, Install Now installs it, Skip This Version stays quiet until the next one, and ✕ closes the bar until next time. Help ▸ Check for Updates… checks straight away. Installing downloads the file for the system, checks it against the SHA-256 GitHub lists for it, unpacks it next to the app, and restarts into the new version (the old one is kept until the new one is in place).

Run from source (a git clone), the app never changes itself: the bar's button says How to Update and explains git pull. It only appears when the clone is older than the latest release. See openprocess/gui/studio/updates.py.


Limitations and roadmap

Plainly stated:

  1. A subpage used by several substitution transitions (one module, several instances) is reported as a problem rather than simulated: give each use its own copy of the page. Subpages used once, at any depth, simulate.
  2. No CPN monitors or simulation reports, and no fairness properties in the state space report (it says so).
  3. CPN ML is a large subset, not all of Standard ML: no exception declarations or handle, no datatype or structure declarations, and characters are one-letter strings. See docs/how-it-works.md.
  4. Alignments are exact but unoptimised: they can take seconds on heavily concurrent models. They run in the background.
  5. Plain Petri nets live on one page.
  6. Regions are found exhaustively, so only for transition systems of up to 26 states (the result says when this limit is hit), and label splitting for transition systems that are not elementary is not suggested yet. Transition systems are typed, not drawn.

Next up: several instances of a subpage, CPN monitors, and signed apps that open without a security prompt.

Licence

MIT. See LICENSE.

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