Factory skill

---
name: factory
description: Turn a one line description of a factory ("a line that makes 2,000 e-bike motors a day", "a bakery that bakes 10,000 croissants an hour", "a battery cell gigafactory") into a single self-contained HTML page with a live 3D tilt-shift miniature of that factory, driven by a real discrete event simulation (stations, cycle times, batches, finite buffers, shifts, breakdowns, scrap) with a live HUD for throughput against target, takt, utilization, WIP, lead time and the bottleneck, where clicking a station lets you add a machine or change a cycle time and watch the bottleneck move. Use it whenever someone wants to see, size, explain or pitch a production line, plant, assembly line, process or factory, asks "how many machines do I need", "where is the bottleneck", "can this line make N a day", wants a factory simulation or digital twin demo, or describes a product and a volume, even if they never say "simulation".
---

# Factory

**Describe a factory in one line. Claude builds it as a live 3D simulation you can run.**

The page is a model factory on a table, seen through a tilt-shift lens: a cut-away hall with
the line inside, machines that move while they work, product flowing on conveyors, people, forklifts, a
truck yard. Under it runs a discrete event simulation. Every number on screen comes from that
simulation, never from a script: the throughput, the utilization bars, the WIP, the pulsing red
outline around the bottleneck. When someone adds a machine at the bottleneck, the simulation gets
one more server, the conveyor in front of it drains, and the outline moves to the next constraint.

## The one rule that matters

**The simulation is the explanation, so it has to be true.**

- Cycle times, batch sizes, dwell times, breakdown rates and yields come from how the real process
  works. Use the numbers a process engineer would recognise and say in `note` where they come from
  ("18 min at 180 C", "51 slots, 3 needle head"). When you have to estimate, say "typical".
- Machine counts come from the sizing rule, which the page prints in the inspector:
  `machines = CEIL(rate_in x cycle / (batch x availability x target utilization))`.
- Throughput, utilization and the bottleneck come out of the simulation. Never tune inputs to make
  a nicer result. If the first line misses its target, that is the finding: report it, show it, and
  let the user fix it with the slider.

## Workflow

Run `date` at the start. A factory takes 10 to 25 minutes.

1. **Read the line.** Pull out the product, the volume and the time unit. Fill in what is missing with
   stated assumptions: shifts (2 x 8 h unless the process runs around the clock, like cells,
   chemicals or glass), the product variant ("250 W rear hub motor"), the scope ("the canning hall,
   from bright tanks to pallets"). Say them in one short paragraph before building.
2. **Route.** Write the real process route as 6 to 10 stations, in flow order, with branches where
   sub-assemblies are made in parallel and joined (stator + rotor + housing into motor assembly).
   Each station: what happens, the machine that does it, the cycle time per unit or per batch, the
   batch, MTBF/MTTR if it is a machine that breaks, yield if it is a test or inspection.
   `references/process.md` has typical numbers for common processes and how to pick them.
3. **Pick the token.** One token is one unit unless the line is fast. Choose `perToken` so one token
   leaves the line every 5 s to 2 h (a tray of 40 croissants, a case of 24 cans, a tray of 96 cells).
4. **Write `spec.js`** (schema below). Start from the closest example in `examples/`.