Where does a flow-equivalent-server decomposition of a robot-printer cell go wrong as the inspector speeds up or slows down?
research/robofab-cell-fescsweep
Where does the flow-equivalent-server decomposition of a robot-printer cell err as the inspector speed varies? Error is 0 for fast and slow inspectors but peaks at −2% to −5% just below the knee where inspector and subsystem rates match, ten times the earlier 0.3% mean. Stylised.
What it found
A follow-up to the decomposition project, which reported a 0.32% mean error at one inspection time. Sweeping the inspection time from 0.1 to 100 min in 10 stylised cells (2–6 printers, Erlang-4 print time, illustrative times) against the exact Markov chain, the decomposition’s error is 0.000% for a fast inspector and at most 0.52% for a very slow one, but peaks at −2.2% to −5.0% (mean −3.2%) just below the knee t* = 1/H(N), where the inspector alone matches the subsystem’s rate (0.81–0.99 t*, grid-limited). It is never positive, and smaller cells err more. The explanation (ignored correlation between inspection queue and subsystem state) is untested. Stylised: one job class, exponential load, unload and inspect times.
A figure from its own output
Paper, code and results
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Produced with AI assistance (Claude). Results are from the code in this repository and are simulated or stylised unless the abstract says otherwise; nothing here implies affiliation with or endorsement by any lab, researcher or company cited. MIT licensed.