Lean comes from the Toyota Production System. The Lean Enterprise Institute describes TPS as a way to get the best quality, the lowest cost and the shortest lead time by eliminating waste.
TPS rests on two pillars.
Pillar 1: just-in-time
Make what's needed, when it's needed, in the amount needed. No piles of parts waiting around.
For bots: do the work that's asked for, at the point it's needed.
- Don't generate ten options when one was asked for.
- Don't load every file "just in case." Load the one the job needs.
- Don't run a routine every hour if the report is read once a day.
Extra output costs tokens, and it costs the reader's time.
Pillar 2: jidoka
LEI describes jidoka as letting machines and operators detect an abnormality and stop work immediately. It goes back to Sakichi Toyoda's loom, which stopped itself when a thread broke. One person could then watch many looms, because they didn't have to stare at each one.
For bots: when something is off, stop and say so.
- A file is missing? Stop and ask. Don't guess.
- A figure doesn't match its source? Hold the report.
- Instructions conflict? Flag it.
This is what lets one person oversee several bots. They don't have to read every line, because the bots raise their hand.
Waste
Lean names kinds of waste: overproduction, waiting, transport, extra processing, inventory, motion and defects. Some translate well:
| Lean waste | Bot version |
|---|---|
| Overproduction | Long answers nobody asked for |
| Extra processing | Redoing work that was fine |
| Inventory | Drafts piling up unreviewed |
| Defects | Wrong output that has to be fixed |
| Waiting | A person waiting on a bot, or a bot waiting on a person's yes |
Standardized work and kaizen
LEI notes that TPS improves through standardized work and kaizen (small continuous improvements), following PDCA. For bots, standardized work is the skill. Kaizen is a small edit to it, tested and recorded. See Work instructions are skills.
Where bots differ
Some Lean ideas don't map well. Motion and transport waste are about people walking and parts moving. For bots they're a stretch. Takt time, the pace set by customer demand, assumes steady repeated work; much bot work is one-off.
And jidoka only works if the bot can tell something is wrong. A bot that doesn't know it's wrong won't stop. That's why checks against real sources matter.
Back to Engineering tools for bots.