Twinworks Buffer & Parameter Sweep

Sweep a buffer size (or any parameter) and get the throughput curve with confidence intervals.

Model or project JSON

A Twinworks project (.twinworks.json, format "twinworks-project") or a bare model with "nodes" and "links". Times in seconds, lengths in metres. Leave empty and pick a template instead.

Or start from a template

Object id

Id of the buffer/machine/conveyor/source to change, or pool:<id> for an operator pool. Default for the bottleneck template: B2.

Parameter

From

Step

Replications per value

Run length per replication h

Overrides the model setting.

Try an example: Bottleneck demo: buffer B2 from 1 to 10 · 3-station line: arrival interval 45…70 s

How it works

Runs a Twinworks factory model repeatedly while one parameter changes — typically the capacity of a buffer from 1 to 10 places, but also servers, cycle times, MTTR, batch sizes, conveyor speed or the number of operators. Returns throughput, lead time and WIP per value with confidence intervals, plus the knee point where extra capacity stops paying off.

For each parameter value the model is copied, the parameter is set and the model is simulated with the same seeds (common random numbers), so differences between values are not masked by random noise.
Throughput, lead time and WIP are reported as Student-t intervals across replications.
Knee point = smallest value whose mean throughput is at least 98 % of the best mean throughput in the sweep: beyond it, more buffer mostly adds WIP and lead time (Little’s law).

The sweep varies one parameter at a time; interactions between buffers are not optimised jointly.

Sources

Law, A. M.: Simulation Modeling and Analysis, 5th ed. (McGraw-Hill, 2015) — event scheduling, replications, confidence intervals (McGraw-Hill)
Roser, Nakano & Tanaka: A practical bottleneck detection method (Winter Simulation Conference 2001) (WSC)
Hopp & Spearman: Factory Physics, 3rd ed. — Little’s law, VUT/Kingman equation, line throughput (Waveland Press)
Nakajima, S.: Introduction to TPM — Overall Equipment Effectiveness = availability × performance × quality (Productivity Press)
Little, J. D. C.: A proof for the queuing formula L = λW (Operations Research 9(3), 1961)

For scripts and AI agents

JSON API: POST https://twinworksbuffersweep.usefulweb.site/api/v1/calculate (same calculation as this page)
Interface description: OpenAPI 3.1 · AI guide: llms.txt
MCP server (Streamable HTTP): https://twinworksbuffersweep.usefulweb.site/mcp · tool name twinworks_buffer_sweep

Example request

curl -s -X POST https://twinworksbuffersweep.usefulweb.site/api/v1/calculate \
  -H 'content-type: application/json' \
  -d '{"template":"bottleneck-buffer-sizing","target":"B2","parameter":"capacity","from":1,"to":10,"step":1,"replications":4,"horizonHours":6}'

Related tools

Twinworks Factory Simulation – Simulate a production line: throughput, lead time, WIP, OEE and the bottleneck, with CIs.
Twinworks Bottleneck Analysis – Find the constraint of a production line and test fixes: ranked bottlenecks with what-if gains.