Queueing Network — Car Service Centre
A main-dealer workshop taking 4.2 vehicles an hour, with a parts-window loop that sends bays back into the queue and a road-test pair that turns out to be the real constraint rather than the ten workshop bays.
Make it your own.
title "Main dealer service centre — a working day"
target 85%
arrivals "Booking in" 4.2/h
station "Booking in" { servers: 1; service: 9m }
# Fault-finding time is wildly variable — an intermittent electrical fault
# and an oil-change inspection share this queue (cv 1.45).
station Diagnostics { servers: 3; service: 42m; cv: 1.45 }
station "Workshop bay" { servers: 10; service: 1h20m }
station "Parts window" { servers: 1; service: 12m; capacity: 14 }
station "Road test + handover" { servers: 2; service: 25m }
route "Booking in" -> Diagnostics 0.55
route "Booking in" -> "Workshop bay" 0.45 # booked jobs skip diagnosis
route Diagnostics -> "Workshop bay" 0.86
route Diagnostics -> exit 0.14 # advisory only, no work
route "Workshop bay" -> "Parts window" 0.34
route "Workshop bay" -> "Road test + handover" 0.66
route "Parts window" -> "Workshop bay" 1.0 # back to the bay with the part
route "Road test + handover" -> Diagnostics 0.07 # fault not cleared
# The remaining 0.93 leaves the network — an unrouted remainder is an
# implicit exit, so no explicit exit route is needed here.