usefulweb.site Twinworks

Factory digital twin & production simulation

Twinworks

Model a production line, simulate it and find the bottleneck — free, in your browser.

Twinworks is a factory digital twin that runs entirely in your browser. Draw a production line on a floor plan with sources, buffers, machines, assembly stations, conveyors, quality checks and operators, then watch a seeded discrete-event simulation animate it in 2D or 3D. Live KPIs show throughput, lead time, WIP with a Little’s-law check, OEE per machine, state Gantt charts and the bottleneck, and the scenario manager, parameter sweeps and cost model turn it into a what-if laboratory.

Launch Twinworks → Tutorials

Free · runs in your browser · no sign-up · Version 1.0.0

Screenshots

Features

  • Floor-plan editor

    Drag sources, buffers, machines, assembly, splits, conveyors, quality checks and sinks onto a metre grid, connect them with arrows, snap, align, copy and undo.

  • 2D plan and 3D view

    Switch between the technical plan and a WebGL 3D/isometric view of the shop floor with machines coloured by state and parts moving along the line.

  • Own simulation engine

    Seeded discrete-event simulation with a binary-heap event calendar, warm-up, replications and Student-t confidence intervals — the same code powers the API.

  • Realistic randomness

    Constant, uniform, triangular, truncated normal, exponential and lognormal cycle times, arrivals by interval, schedule, batch or unlimited supply.

  • Failures & maintenance

    Breakdowns with MTBF/MTTR distributions on calendar or operating time, planned maintenance, setups on product change and batch processing.

  • Operators & shifts

    Shared operator pools, shift calendars with breaks and weekends; machines wait for operators and stop at shift end.

  • Conveyors & routing

    Accumulating and non-accumulating conveyors with length, speed and pitch; routing by percentage, round robin, shortest queue, product type or product routing.

  • Assembly, quality & rework

    Kit assembly from several feeders, inspection with scrap and rework loops, product variants with colours and job-shop routings.

  • Live KPI dashboard

    Throughput per hour, lead-time histogram, WIP over time with Little’s law, queue lengths and utilization/blocked/starved/down bars while the animation runs.

  • OEE & state Gantt

    Availability × performance × quality per machine and a state Gantt chart that shows exactly when each station worked, waited or broke down.

  • Bottleneck detection

    Active-period method with sole and shifting bottlenecks plus utilization ranking, with concrete recommendations and what-if gains.

  • Scenarios side by side

    Clone the model, change it and compare scenarios with paired confidence intervals on the same random numbers.

  • Parameter sweeps

    Sweep a buffer size, server count, cycle time, MTTR or crew size and see the throughput curve with its knee point.

  • Cost model

    Machine hourly rates, labour, material, scrap and overhead roll up to a cost per good part and profit per scenario.

  • Reports & exports

    Printable KPI report, CSV event log and time series, JSON model, PNG/SVG of the layout and every chart — all generated locally.

  • API & MCP tools

    Simulate, rank bottlenecks, balance lines, sweep buffers and check queueing formulas from scripts or AI agents with the same engine.

Templates

Start from a ready-made project and change it to fit.

  • 3-station line

    A simple serial line: random arrivals, three machines with triangular cycle times and two small buffers. The classic starting point.

    Open in app: 3-station line →

  • Line with failures & shifts

    Saturated three-machine line with random breakdowns (MTBF/MTTR), planned maintenance, a two-shift calendar with breaks and an operator pool. Shows availability losses in OEE.

    Open in app: Line with failures & shifts →

  • Assembly with two feeders

    Housings and covers are made on two feeder lines and joined at an assembly station (1 housing + 2 covers), followed by an end-of-line test with scrap and a rework loop. Assembly needs an operator from a shared pool.

    Open in app: Assembly with two feeders →

  • Job shop with routings

    Three product families visit four machine groups in different orders (product routings). A transport hub dispatches each part to the next step of its routing; the mill needs a 2.5-minute setup whenever the product family changes.

    Open in app: Job shop with routings →

  • Bottleneck demo with buffer sizing

    Five stations, tiny buffers and one variable station in the middle. Use the bottleneck analysis to find the constraint, then sweep the buffer in front of it from 1 to 10 to see where more space stops paying off.

    Open in app: Bottleneck demo with buffer sizing →

  • Conveyor packaging line

    A bottling and packaging line: filler, non-accumulating transfer belt, labeller with micro-stops, accumulating buffer table, case packer (12 bottles → 1 case), checkweigher and a pallet conveyor. Shows how accumulation decouples a failing labeller from the packer.

    Open in app: Conveyor packaging line →

  • Queueing validation (M/M/1)

    Poisson arrivals (mean 60 s) and an exponential machine (mean 48 s, ρ = 0.8) with an unlimited queue. Theory: mean wait in queue Wq = ρ/(μ−λ) = 192 s, Lq = 3.2. Run 20 long replications and compare the confidence interval.

    Open in app: Queueing validation (M/M/1) →

For AI agents

Twinworks runs on a deterministic engine. The same functions are available as tools with a JSON API and MCP, so scripts and AI agents get exactly the results the app shows.

  • Twinworks Factory Simulation – Simulate a production line: throughput, lead time, WIP, OEE and the bottleneck, with CIs.
    Tool page · POST https://twinworks.usefulweb.site/api/v1/tools/twinworks-simulate/calculate · MCP twinworks_simulate
  • Twinworks Bottleneck Analysis – Find the constraint of a production line and test fixes: ranked bottlenecks with what-if gains.
    Tool page · POST https://twinworks.usefulweb.site/api/v1/tools/twinworks-bottleneck-analysis/calculate · MCP twinworks_bottleneck_analysis
  • Twinworks Line Balancing – Assign assembly tasks to stations for a takt time: efficiency, balance delay and smoothness index.
    Tool page · POST https://twinworks.usefulweb.site/api/v1/tools/twinworks-line-balance/calculate · MCP twinworks_line_balance
  • Twinworks Buffer & Parameter Sweep – Sweep a buffer size (or any parameter) and get the throughput curve with confidence intervals.
    Tool page · POST https://twinworks.usefulweb.site/api/v1/tools/twinworks-buffer-sweep/calculate · MCP twinworks_buffer_sweep
  • Twinworks Queueing Check – M/M/1, M/M/c, M/D/1, M/G/1 and Kingman waiting times — optionally verified by simulation.
    Tool page · POST https://twinworks.usefulweb.site/api/v1/tools/twinworks-queue-formulas/calculate · MCP twinworks_queue_formulas

Build a project through the API, then open it in the app with a link to https://twinworks.usefulweb.site/app#project=<base64url JSON>.

Import & export

Import

  • Twinworks project (.twinworks.json)
  • Twinworks model JSON
  • Project link (#project=…)

Export

  • Twinworks project (.twinworks.json)
  • CSV event log
  • CSV time series
  • CSV station KPIs
  • PNG and SVG of the layout
  • PNG and SVG of charts
  • Printable KPI report (PDF via print)

Keyboard shortcuts

Keyboard shortcuts in Twinworks
KeysAction
VSelect tool
CConnect tool
1 … 8Place source, buffer, machine, assembly, split, conveyor, quality check, sink
SpacePlay / pause simulation
.Single step (next event)
Shift + FFast-forward to the end
Ctrl + RRun experiment (replications)
Ctrl + Z / Ctrl + YUndo / redo
Ctrl + C / Ctrl + V / Ctrl + DCopy / paste / duplicate
DeleteDelete selection
Arrow keysNudge selection (Shift = 1 m)
RRotate selection 90°
FZoom to fit
GToggle snap to grid
TabSwitch 2D plan / 3D view
Ctrl + SSave project file
Ctrl + OOpen project file
?Keyboard shortcuts

Frequently asked questions

Is Twinworks really free?

Yes. Twinworks runs in your browser; projects are stored locally in IndexedDB and as files you download. There is no account and nothing is uploaded unless you call the API yourself.

How accurate is the simulation?

The engine is validated against queueing theory: M/M/1 and M/M/c waiting times fall inside the simulated confidence intervals, a deterministic line produces exactly 1 ÷ bottleneck cycle time, and Little’s law holds within a few percent in steady state. The accuracy of your model depends on your input data.

Why do I need replications and a warm-up?

A single random run is one sample. Replications with different seeds give a confidence interval for each KPI, and the warm-up removes the empty-line start so averages describe steady operation.

How is the bottleneck detected?

With the active-period method: whichever station has been working (or under repair, in setup, waiting for an operator) without interruption the longest is the bottleneck at that moment. Overlaps between successive bottlenecks are shifting bottlenecks. Utilization is shown as a second indicator.

How is OEE calculated?

Availability = run time ÷ planned time (breakdowns and setups are losses, shift breaks and planned maintenance are not planned time), performance = ideal cycle time × parts ÷ run time, quality = good ÷ processed parts. OEE is their product.

Can an AI agent build and run a model?

Yes. The project format is documented as a JSON schema; the twinworks-simulate, twinworks-bottleneck-analysis, twinworks-buffer-sweep, twinworks-line-balance and twinworks-queue-formulas tools are available via the JSON API and MCP, and results contain an “Open in Twinworks” link.

Can I import data from my MES or ERP?

Models are plain JSON, so a script can generate them from your data. Direct connectors to MES/ERP systems are not included.

Limitations

What Twinworks does not do (yet):

  • Discrete parts only: no continuous flow (liquids, bulk material) or fluid tanks.
  • Transport between objects is instantaneous unless you model it as a conveyor; there are no AGVs, forklifts or path finding.
  • Operators are pooled resources without walking times, skills matrices or individual schedules.
  • Conveyors use a slot model (length ÷ pitch) rather than exact physics; merges and curves are not modelled geometrically.
  • The 3D view is a schematic visualisation, not CAD; no import of 3D models or DWG floor plans.
  • No optimisation solver: sweeps change one parameter at a time.
  • API calls are limited to roughly 40 million events per request; long studies run best in the app.

Tutorials

Learn Twinworks step by step.

  1. Your first production line in 5 minutesPlace a source, a buffer, a machine and a sink, connect them, press play and read throughput, lead time and the bottleneck. No account, nothing to install.Beginner 5 min
  2. Failures, shifts and operatorsMake the model realistic with breakdowns (MTBF/MTTR), planned maintenance, setups on product change, shared operators and a two-shift calendar with breaks.Intermediate 12 min
  3. Find the bottleneckUse the active-period method, utilization, the state Gantt chart and OEE to find what really limits your line — and test fixes with the what-if analysis before spending money.Intermediate 10 min
  4. Scenarios and buffer sweepsClone your model into what-if scenarios, change them, compare them side by side with paired confidence intervals, and sweep a buffer size to find the knee of the throughput curve.Intermediate 12 min
  5. Assembly, routings and qualityJoin parts from two feeder lines at an assembly station, add an end-of-line test with scrap and a rework loop, and model a job shop where each product family follows its own routing.Advanced 15 min
  6. Line balancing and cost per partDistribute assembly tasks over stations for a takt time with the ranked positional weight method, turn the result into a simulated line, and read the cost per good part.Intermediate 10 min
  7. Automate with the API / MCPRun the Twinworks engine from scripts and AI agents — simulate a model, rank bottlenecks, sweep a buffer, balance a line and check queueing formulas with real JSON requests and responses.Advanced 15 min

Ready to try it?

Launch Twinworks →

Other premium apps