Student Guide

Build a valid plant

Positions are the bottom-left corners of footprints. Keep every stationary Source, Machine, Buffer, and Sink within the plant and at least six feet from the next footprint. plant.validate() reports missing connections, invalid assignments, insufficient skills, and layout problems before simulation.

Workers remain where their last task ended. Manual transport is:

  1. wait for the Worker;
  2. Worker travels empty to pickup;
  3. Worker carries the Part to its destination;
  4. Worker remains there.

A Machine's assigned Worker is occupied for the full operation. Multiple assigned operators divide base processing time perfectly. Forklifts require both equipment and an assigned Worker; AGVs are autonomous.

For a step-by-step build, see the layout tutorials. They explain coordinate planning, route connections, material-handling choices, reusable configuration, and redesign experiments.

Interpret output

result.headline_metrics contains the primary KPIs. Scheduled throughput uses the configured arrival window; elapsed throughput includes WIP drain time. Lead time includes waiting, movement, processing, blocking, and resource delays. Average WIP and queue/Buffer occupancy are time-weighted.

Use resource tables directly:

result.machine_metrics
result.worker_metrics
result.transporter_metrics
result.buffer_metrics
result.product_metrics
result.from_to_matrix

Product metrics include scheduled and elapsed throughput, lead and waiting times, exact time-weighted WIP, maximum WIP, travel, and scrap system time. Good-unit lead time and creation-to-scrap system time are reported separately.

The normal report deliberately does not name the bottleneck. Use utilization, queue accumulation, waiting, blocking, and travel evidence to form an engineering conclusion.

Experiments

Copy before changing a scenario:

redesign = plant.copy()
redesign.name = "Redesign 1"
redesign.move(machine, (40, 20))
redesign_result = redesign.run(seed=42)
comparison = compare(baseline_result, redesign_result)

Use fixed seeds for graded stochastic work. Export CSV results and write a conclusion that connects hypothesis, evidence, and engineering implications.