Open source · Local-first · No accounts

Draw your process.
See the schedule.

Caladia is a business process simulator for the rest of us. Sketch your workflow as a block diagram and a Gantt chart materialises beneath it — complete with critical path, resource conflicts, and Monte Carlo risk analysis. Plans live as plain JSON files on your disk. No accounts, no backend, no server to subpoena.

Your diagram
go Spec 3 days Build 8 days Review p=0.8 Test plan 5 days Ship 2 days
Live Gantt
M T W T F M T W Spec Build Test plan Review Ship critical path · 18 working days
what's inside

A complete planning workshop, in your browser tab.

Everything teams currently piece together from MS Project, Excel, and a whiteboard — in one focused tool.

Block diagram canvas

Drag activities, decisions, and start/end nodes. FS, SS, FF, and SF dependencies with signed lag. Multi-select, copy/paste, full undo history.

Live Gantt chart

Auto-updates on every edit. Critical path highlighted, non-working days shaded, dependency arrows, collapsible loop groups, dark mode.

Monte Carlo simulation

Triangular, PERT-beta, or normal distributions per node. Seeded reproducible runs. P50/P80/P95, criticality index, tornado chart.

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Decision gates

Diamond-shaped review nodes with a pass probability and a failure delay. Failed reviews extend the chain rather than branching it.

Loops & iterations

Wrap nodes into iterative loops with configurable kickout: max iterations, time budget, convergence, or external trigger. Iteration counts modeled in Monte Carlo.

Resources & calendars

Resource pools with custom calendars. Per-assignment conflict policy: intersection, resource-wins, or activity-wins. Utilization histogram included.

Scenario comparison

Create named what-if scenarios by overriding node durations. Compare deterministic CPM results side-by-side. See critical-path changes and working-day delta at a glance.

Sub-system blocks

Wrap a group of nodes into a single visual block with one entry and exit. Drill in to edit, save out as a reusable .calasub file.

.mpp .xlsx AI

AI-guided imports

Bring an MS Project file, a Gantt spreadsheet, or a process slide deck. Caladia ships a portable LLM authoring skill — use any model you want, with no embedded API key.

how it works

Three steps. Zero accounts.

From cold start to a working schedule in minutes.

01

Sketch the process

Drag in nodes, draw arrows, name things. The canvas feels like a whiteboard — only it knows about durations and dependencies.

Duration 3d Resources Alex Lag +1d Spread PERT
02

Add the metadata

Click any block to set duration, distribution, resources, and lag. Each field has a sensible default — fill what matters.

P80 = 22 days
03

Read the schedule

The Gantt updates live. Run Monte Carlo to see risk percentiles. Compare what-if scenarios. Save to a .cala file when you’re done.

.cala

One file. Plain JSON. Forever readable.

The project format is a documented Zod schema, validated on every load. No proprietary blobs, no “upgrade required” dialogs, no vendor that can disappear and take your plans with it.

Stop wrestling MS Project. Start drawing.

Caladia is free, open-source, and runs in any modern browser. Nothing to install, nothing to configure.