Construction planning

Open Planner Studio

Open-source construction planning with Gantt charts, critical path, resources and levelling, baselines and progress — and native IFC 4.3 as the file format. One task grid for your whole schedule: next to the Gantt and as a full table view, edited like a spreadsheet. Also opens MS Project (.mpp) files natively. On your desktop and straight in the browser.

Download v2026.9.0 Open in your browser View source
Open Planner Studio — Gantt-planning met WBS-structuur, relatiepijlen en voortgangsbalken, drie projecten tegelijk open en het eigenschappenpaneel met CPM-resultaat rechts
Open Planner Studio — de volledige tabelweergave met WBS, duur, geplande start en einde, taaktype, kritiek pad, totale speling en voortgang naast elkaar, met drie projecten open en het eigenschappenpaneel rechts
Open Planner Studio — Gantt met werkonderbrekingen als losse blokken met verbindingslijn, zoals gelezen uit een MS Project (.mpp)-bestand, met kritiek pad en eigenschappenpaneel
Open Planner Studio — resource-bibliotheek die als bron boven meerdere projecten staat, met arbeid, materieel en onderaannemers
Open Planner Studio — bezettingsoverzicht van de resource-bibliotheek over meerdere geopende projecten, met dubbelgeboekte dagen gemarkeerd en een histogram per resource
Open Planner Studio — resource-histogram onder de Gantt, met overallocatie en nivellering
Open Planner Studio — Rapport-tab met papierformaat, lettergrootte en afdrukvoorbeeld van de Gantt
Open Planner Studio — ingebouwde handleiding met quick-start en praktijkgidsen, waaronder het koppelen van een AI-assistent

One table for your whole schedule — and you edit it like a spreadsheet

The task list beside the Gantt and the full Table view are now the same table: the same columns, the same shortcuts, the same way of editing — wherever you work. It stays fluid at thousands of tasks, you move from cell to cell with the keyboard, and you paste whole blocks in from your spreadsheet in one go. Dependencies are now edited right in the cell; the separate Relations tab had become redundant and has been retired.

  • One table, two places — the same columns, shortcuts and edits beside the Gantt and in the Table view. Your column choice, widths and order are remembered per place.
  • Paste from your spreadsheet — several cells at once, applied in full or not at all. Values stay values instead of flattening to text, and read-only cells are skipped.
  • Dependencies in the cell — edit relations and jump to the linked task without leaving the table. The separate Relations tab has been retired as a result.
  • Days and hours — you choose per task whether its duration counts in days or in hours. An hour task consumes real working minutes on its own calendar, even when that calendar has a break in it.
  • Also new: your own task types, reports on A2 with a baseline overlay and status line, automatic saving back to your own file, and an interface that can follow the system theme.

We are looking for testers: work planners, schedulers, project leads and BIM coordinators. Try Open Planner Studio right in your browser and tell us what you think — your feedback helps shape where it goes.

Try the live demo → Join as a tester

Download v2026.9.0

Windows
7.3 MB
Download .exe
macOS (universal)
15.4 MB
Download .dmg
Linux (deb)
8.3 MB
Download .deb
Linux (rpm)
8.3 MB
Download .rpm
Linux (AppImage)
82.2 MB
Download AppImage
Linux (snap)
7.5 MB
Download .snap

Rather not install anything? Open Planner Studio also runs fully in your browser — including opening and saving files.

Features

AI assistant via MCP

An MCP server is built into the app, so an AI client such as Claude Code can read and edit your schedule directly. Switch it on in the AI tab, with a pause button, read-only mode and automatic backups.

Gantt charts

Interactive HTML5 Canvas Gantt with drag and drop, zoom and timeline navigation. Drag a whole selection vertically, collapse non-working days out of the timeline and select with Ctrl+click. Week numbers in the header.

Critical path (CPM)

Automatic critical path calculation with float, near-critical work, multiple critical paths and deadline analysis. A "dates as recorded" view shows a file exactly as it recorded its own dates, when those differ from recalculation.

WBS & table view

Hierarchical task structure with collapsible chapters. Beside the Gantt and in the full Table view you work in the same table: cell to cell with the keyboard, blocks pasted in from your spreadsheet, dependencies in the cell, columns you choose and pin, rows you drag. It stays fluid at thousands of tasks too.

Your own task types

Alongside the built-in types you can define your own task types. They are reusable on your installation, and their name and identity travel with the project — so what a task is stays readable after an IFC exchange or on another machine.

Automatic saving

Once your project has a file the app is allowed to write to, you can have it written back periodically — with no dialog. It deliberately stays separate from crash recovery: a document that has never been saved is never quietly overwritten, and the recovery snapshot keeps running alongside it.

Native IFC 4.3

Your schedule is an IFC file (buildingSMART standard). With a built-in IFC code editor to generate and apply.

Resources & levelling

Labour, equipment and subcontractors with a histogram and automatic levelling of overallocation. Move assignments while keeping units and curve.

Resource libraries

Share one resource pool across several projects. The library is the source, the project shows what it actually uses, and deviations are flagged so you can resolve them. The occupancy overview adds up every open project — as a table and as a histogram — and marks the days where the committed load exceeds the available capacity.

Baselines & progress

Capture multiple baselines and record progress with a status date, actual start and a cleaned-up progress line.

Calendars & hourly planning

Construction-specific calendars: public holidays, building recess, frost delay, inspection moments and phasing, plus a configurable break in the daily pattern. Per task you choose whether the duration counts in days or in hours; an hour task consumes real working minutes on its own calendar instead of being quietly converted to whole days.

Desktop and browser

Runs natively on Windows, macOS and Linux, but also fully in the browser — including open, save, auto-save and crash recovery.

Exchange

Import and export IFC, CSV, MS Project (.xml) and Primavera P6 (.xml) — no intermediate steps or conversion tools.

MS Project (.mpp) import

Opens .mpp files natively, with no Microsoft Project or converter involved — date-faithful to the minute across a 216-file test corpus. Split tasks, resource leveling, timephased assignments and manually scheduled tasks are read and shown as interrupted bars in the Gantt, print preview and PDF export; nothing from the source file is lost, even after you edit it.

4D BIM-ready

Your schedule is an open IFC 4.3 file. BIM software can lay it directly alongside your building model for 4D analysis of the construction sequence, with no conversion needed.

Reporting & printing

Live print preview in the ribbon and export to a real high-resolution PDF (±220 DPI). Paper up to A2, a baseline overlay, a status or progress line, bars coloured by task, category or resource, and non-working days you can compress. Configurable font size, a header that repeats on every page and a timeline that may span several pages. Your settings are remembered.

Manual inside the app

Press F1 for an offline manual, available in all fourteen languages: quick start, fifteen practical guides — including resource libraries and connecting an AI assistant — and sixteen reference pages, plus eight sample projects to practise on.

Shortcuts & context menus

Full overview via Ctrl+/ and rich right-click menus on the task row, Gantt bar, canvas and band header. Per-task notes with a tickable checklist.

14 languages

Nederlands, English, Français, Deutsch, Español, Italiano, Português, Polski, Türkçe, 中文, 日本語, 한국어 and RTL support for العربية and فارسی.

Ribbon toolbar

Familiar Office-style ribbon with tabs: Home, Planning, Resources, View, Settings, Table, IFC and Report — plus an AI tab once AI mode is on. Relation actions sit in the task groups themselves.

Technology

Tauri 2

Native desktop app with a Rust backend for Windows, macOS and Linux.

React 19 + TypeScript

Component-based UI with Zustand + Immer for state management.

HTML5 Canvas 2D

Gantt rendering. TailwindCSS 4 for styling, Vite 7 as the build.

Frequently asked questions

Can I open files from Microsoft Project or Primavera P6?

Yes. Open Planner Studio opens MS Project (.mpp) files natively — no Microsoft Project or external converter needed — and is date-faithful to the minute across a 216-file test corpus; split tasks, leveling delay, timephased assignments and manually scheduled tasks are read and shown. The app also imports and exports MS Project (.xml) and Primavera P6 (.xml) directly, with no intermediate step or conversion tool. IFC and CSV are supported as well.

Do I have to install anything?

No. The full application runs in the browser, including opening and saving files, auto-save and crash recovery. In Chromium browsers (Chrome, Edge, Brave, Opera, Vivaldi) Ctrl+S saves back over the same file, just like on the desktop; Firefox and Safari fall back to the file picker. If you do want to install, there are builds for Windows, macOS and Linux.

What file format is my schedule saved in?

IFC 4.3, the open buildingSMART standard. Your schedule *is* an IFC file — there is no proprietary, closed format. That keeps your data readable outside this application, and lets BIM software lay your schedule directly alongside an IFC building model for 4D analysis of the construction sequence.

What exactly can an AI assistant do with my schedule?

Since v2026.7.13 the app ships a built-in MCP server. An AI client such as Claude Code can read your schedule through it — project overview, tasks, critical path, resources, histogram, calendars and baselines — and edit it too. You switch the bridge on in the AI tab and stay in control: there is a pause button, a read-only mode, automatic backups and an activity panel listing every call the assistant made.

What does Open Planner Studio cost?

Nothing. The application is free and open source under the LGPL-3.0 licence. No subscription, no per-seat licence fees.

Which systems does it run on?

Windows (.exe), macOS (universal .dmg, both Intel and Apple Silicon) and Linux (.deb, .rpm, AppImage and snap). Plus fully in the browser.

Does it fit construction practice?

Yes. You set up construction-specific calendars with public holidays, building recess, frost delay, inspection moments and phasing, and you can plan down to hour level. The interface is available in fourteen languages.

Can I see which tasks drive the end date?

Yes. The critical path is calculated automatically, with float, near-critical work, multiple critical paths and deadline analysis. Resources get a histogram with automatic levelling of overallocation, and multiple baselines let you track deviations from the original plan.

Live demo → All releases → GitHub →

Release notes

v2026.9.0 · 2026-09-02 · The headlines per version. Use More for the full notes.

  1. v2026.9.0

    Latest

    13 days · 289 commits · +60,405 lines of code

    TASK GRID

    Edit faster in one shared task grid

    Use the same accessible, configurable grid in the Gantt and full Table view.

    • PLANNINGPlan in days or hours
    • REPORTSSharper reports and preview
    • AUTOSAVEReal AutoSave per document
    • GANTTNavigate the plan more directly
  2. v2026.8.1

    2 days · 360 commits · +45,066 lines of code

    MS PROJECT

    Import with the dates from your plan

    Open MS Project schedules while retaining recorded planning dates.

    • RESOURCESResource library occupancy
    • RELATIONSClearer milestone relations
    • TASKSConsistent task types
    • EXAMPLESRicher example projects
  3. v2026.8.02026-08-17
    • Resource libraries: a new occupancy overview shows, per library item, how much of it is committed across all your open documents — as a table and as a…
    • Relations on milestones and summary tasks: dragging a relation from a milestone works again, relations that cannot have any effect are now marked in the…
    • New tasks inherit their task type from the parent task, both when you add them yourself and when the AI assistant creates them.
    • The bundled examples now ship with resource sets, so the demo projects show resource planning and the occupancy overview with real data.
    • Fixes: WBS numbering stays in sync when moving tasks, deleting several tasks at once is a single undo step, the saved theme is applied before the first paint…
  4. v2026.7.142026-07-30
    • Gantt dependencies: finish-to-finish and start-to-finish arrows were drawn from the wrong edge of the successor — they now anchor correctly, on screen and in…
    • Split view and navigation: each pane now has its own scrollbar and mini-map, there is a real vertical scrollbar for large task lists, and Collapse/Expand are…
    • Right-hand rail: the resource dock and the task properties panel now sit open side by side in one resizable rail, instead of one replacing the other.
    • Resources: adding one opens an inline editable row that no longer jumps away after you type, with full keyboard navigation (Enter / Shift+Enter to move and to…
    • Shortcuts and bars: Ctrl+Shift+H toggles the resource histogram, and the duration pill now updates live while you drag a bar edge.
  5. v2026.7.132026-07-27
    • AI assistant: an MCP server is now built into the app, so an AI client such as Claude Code can read and edit your planning directly. Turn it on in the new AI…
    • Resource libraries: share one resource pool across projects. The library is the source, the project shows what it actually uses, and deviations are marked so…
    • Gantt and table: drag a whole selection vertically, collapse non-working days out of the timeline, week numbers in the header, Ctrl+click multi-select, and the…
    • Reports: adjustable font size, repeat the header on every page, spread the timeline over several pages, and every report setting is remembered. Interface font…
    • Fixes: dates could shift a day in some timezones; an apostrophe or semicolon in a task name could corrupt a saved file; crash recovery could lose dependencies…
  6. v2026.7.122026-07-23View on GitHub →
  7. v2026.7.112026-07-20
    • Bestanden openen en opslaan in de browser. De web-versie was tot nu toe volledig bruikbaar behalve bestand-I/O — die zat achter een desktop-check. Dat gat…
    • Openen, opslaan, opslaan-als en exporteren (IFC, CSV, MS Project, Primavera P6) werken nu ook in de browser.
    • Browsers met de File System Access API — in de praktijk de Chromium-familie (Chrome, Edge, Opera, Brave, Vivaldi, …): je opent een bestand, bewerkt het en…
    • Browsers zonder die API — op dit moment Firefox en Safari: nette terugval, openen via een bestandskiezer en opslaan als download. In-place overschrijven…
    • De app kijkt naar de mogelijkheid, niet naar de browsernaam (feature-detectie). Rolt een browser de API later alsnog uit, dan werkt in-place opslaan daar…
  8. v2026.7.102026-07-10
    • Volledige gebruikershandleiding, offline beschikbaar — druk op F1 of ga naar Bestand → Help: een quick-start ("je eerste planning in 10 minuten"), negen…
    • Drie woningbouw-showcases in oplopende schaal: een verbouwing (~20 taken, het instapvoorbeeld), een rijtje van 6 woningen (~80 taken — resources…
    • Nivellering respecteert nu de statusdatum — bij projecten met ingevoerde voortgang rekende de nivellering intern zonder statusdatum, waardoor conflicten…
    • Geen onterechte "beperking geschonden"-melding meer op taken die aantoonbaar (werkelijke start geregistreerd) precies op hun vastgezette datum zijn gestart.
    • "Exporteer PDF" levert nu een echt PDF-bestand in hoge resolutie (±220 DPI), in plaats van een PNG met een verkeerde naam.
  9. v2026.7.92026-07-07
    • Sneltoetsen-overzicht — druk op Ctrl+/ (of via Weergave → Sneltoetsen) voor een volledig, vertaald overzicht van alle sneltoetsen.
    • Nieuwe sneltoetsen: F2 taak bewerken · Insert taak invoegen boven de selectie · Ctrl+M mijlpaal toevoegen · Ctrl+A alle zichtbare taken selecteren…
    • Rijkere contextmenu's (rechtermuisknop) op vier plekken: taakrij (bewerken, invoegen boven/onder, in-/uitspringen, mijlpaal-toggle, kalender ▸, voortgang…
    • Box-selectie — sleep een kader om meerdere taken tegelijk te selecteren (Ctrl+slepen voegt toe aan de selectie).
    • Toewijzing verplaatsen — verplaats een resource-toewijzing naar een andere taak met behoud van eenheden en curve ("verplaats naar…" in de…
  10. v2026.7.82026-07-07
    • All constraint types, including mandatory pins: alongside the soft constraints (start/finish no earlier/later than), you can now set a Mandatory pin…
    • Hammock tasks: a task whose duration is derived automatically, spanning between a start driver and a finish driver — ideal for overhead items (site hut…
    • External (cross-project) dependencies: link a task to a task in another project file; the date is kept as an anchor you can refresh, and the external task…
    • Near-critical path: tasks with little float (default: 2 working days, adjustable per project) are highlighted amber — so you see which chains become…
    • Multiple critical paths: follow a separate critical path per open end or deadline, each with its own float-path number.
  11. v2026.7.72026-07-06
    • One master switch: hour planning lives behind a single new setting, off by default. Leave it off and the app looks and behaves exactly as before. Files…
    • Work-time bands: calendars can now carry real working times per weekday — multiple blocks per day (morning + afternoon around a break), night shifts that…
    • Shift presets: one click sets up Day shift, 2-shift, Night shift or 24/7 — and you can save your own presets. A full per-weekday editor sits behind "Set…
    • Hours in the schedule: give any task a duration in hours via three synced fields (days, hours, total hours — whole numbers, live-converted through the…
    • Hour timescale: zoom in far enough (with the switch on) and the Gantt shows an hour scale; dragging snaps to whole hours, never finer.
  12. v2026.7.62026-07-04
    • Year-independent holiday generation: holidays are generated from rules (fixed dates, Easter-based, nth-weekday, substitution rules) for the whole project…
    • Seven country sets: Netherlands, Germany (per Bundesland — Fronleichnam in Bavaria, Reformationstag in the north, and so on), Belgium, France, United…
    • Dutch construction holiday (bouwvak) is now opt-in: new projects contain no bouwvak unless you pick a region (North/Central/South) in the wizard…
    • Calendar library: one set of named calendars per project, shared by the project default, tasks and resources. Manage them in the calendar dialog: create…
    • Task-specific calendars: give any task its own calendar (e.g. indoor work continuing through a winter shutdown). The scheduler computes each task's…
  13. v2026.7.52026-07-04
    • Time scale that actually works: pick Year, Quarter, Month, Week or Day and the timeline really changes — the view recenters on what you were looking at…
    • Configurable columns: choose which columns the task table shows, drag them into your order and set widths (in the dialog or by dragging the header). New…
    • Filters: build nested AND/OR filters over any field — built-in fields, activity codes, custom fields and resources — with an editor that adapts to the…
    • Grouping and sorting: group by any field up to two levels (e.g. phase → resource) with band headers and counts — a task with two resources appears under…
    • Layouts: save your combination of columns, filter, grouping, sorting and time scale as a named layout and apply it anytime. Layouts referring to fields a…
  14. v2026.7.42026-07-04
    • Save unlimited named baselines: each baseline is a dated snapshot of the computed schedule (task starts, finishes, durations and the project end). One…
    • Baseline overlay in the Gantt: a slim bar underneath every task shows where it was planned in the active baseline — milestones get a baseline diamond…
    • Variance report: a third report type next to the Gantt and milestone reports. Per task: baseline start/finish, current start/finish, the delta in work days…
    • Saving a baseline while the schedule is out of date shows a "recalculate first (F5)" hint, so you never freeze stale dates.
    • Status date (data date) with real P6 semantics: everything before the line is history, all remaining work is scheduled from the status date forward. No…
  15. v2026.7.32026-07-03
    • Five resource types: labour (people), equipment (cranes, machinery, scaffolding), materials (concrete, steel, timber), subcontractors and crews — crews…
    • Resource calendars and time-phased capacity: give a resource its own working calendar, and let its availability change over time (e.g. three carpenters…
    • Assignments with distribution curves: assign resources to tasks in units per day, spread over the task duration with six curves (uniform, front-loaded…
    • Workload & overallocation engine: every calculation sums the daily load per resource against its capacity; overallocation is flagged in the ribbon and…
    • Resource histogram under the Gantt chart, sharing its timescale: capacity line (stepped when capacity changes over time), red peaks above the line, a…
  16. v2026.7.22026-07-03
    • Start and finish milestones (Primavera P6 model), translated to day-granular scheduling with a boundary model: a start milestone anchors to the *beginning*…
    • Golden invariant: inserting a milestone into a chain never shifts the schedule — for either kind. Existing files keep computing exactly as before (the…
    • Mandatory (contractual) milestones — inspection points, hand-over dates, key dates: a dedicated flag with a double-diamond marker in the Gantt. Date…
    • The ribbon milestone button is now a menu: start milestone, finish milestone, or inspection point (finish milestone + inspection task type +…
    • Milestone overview: a second report type next to the Gantt print — a table with kind, date, constraint/deadline date, float, mandatory flag and a…
  17. v2026.7.12026-07-02
    • All 8 date constraints on tasks: As Soon As Possible (default), As Late As Possible, Start/Finish No Earlier Than, Start/Finish No Later Than, Must Start…
    • P6 "soft" semantics: constraints never break relationship logic. Early-side constraints (SNET/FNET) push the forward pass; late-side constraints…
    • As Late As Possible uses the P6 definition: the task consumes exactly its free float, so successors never move.
    • Deadlines (MS Project model): a soft target date per task, independent of constraints. It only caps the late dates — bars never move; missing it turns the…
    • Negative float: total float is now signed and *critical = float ≤ 0*. Negative float propagates back through the predecessor chain, so you can see exactly…
  18. v2026.7.02026-07-02
    • Lag units per relation: working days (default) or elapsed/calendar days (24/7 — e.g. concrete curing over a weekend). Notation 2d vs 3ed in all…
    • Percentage lag (e.g. SS+50%, MS Project semantics): lag as a percentage of the predecessor's *current* duration, re-evaluated on every schedule…
    • Leads (negative lag) finished: truncated leads and leads exceeding the predecessor duration are now flagged; leads serialize as standard ISO-8601 (-P2D)…
    • Driving vs non-driving relationships (P6 definition): solid vs dashed dependency lines, red for critical driving links, ⚡ indicators in the panels.
    • New Relations tab: every relationship in one sortable, inline-editable table (predecessor, type, lag, successor, driving, relationship free float…
  19. v2026.6.12026-06-29View on GitHub →
  20. v2026.6.02026-06-24
    • Cross-platform auto-update (Windows/macOS/Linux): de app werkt zichzelf voortaan bij. Op Snap via de Snap Store; op een .deb-installatie met een…
    • Multi-document: meerdere projecten tegelijk open, drie wisselstijlen + projectoverzicht, per-document recovery en een 3-weg sluit-bevestiging (Opslaan /…
    • Nieuw-project-wizard met kalender-presets (NL-bouwkalender) en fasering-templates (Woningbouw / Utiliteitsbouw).
    • Taken kopiëren/plakken inclusief subtaken, relaties en resource-toewijzingen.
    • Extensiesysteem + host-SDK + publieke extensie-catalogus.
  21. v2026.2.02026-02-23View on GitHub →

View all releases on GitHub →