Small batches

you are in this shape if

• Problems surface long after they were created
• Big handovers feel efficient and are followed by big surprises
• Changeover cost is the excuse for the batch size

the moves

Cut the changeover first

Batch size is a symptom of setup cost; attack the setup (SMED — minutes, not hours) and small batches become affordable.

Flow one piece

Move work through in the smallest unit that can flow, so a defect surfaces at the second unit, not the ten-thousandth.

Deploy continuously

Ship every small change on its own; the batch of size one turns every failure into a small, attributable failure.

where it was solved

1. 1969ToyotaManufacturingStarting around 1969, Shigeo Shingo worked with Toyota's press shops to separate 'internal' setup steps, which require the machine to be stopped, from 'external' ones that can be done while it keeps running, and to convert as many internal steps to external as possible. This turned die changes that had taken roughly one to several hours into changes measured in single-digit minutes — the method he later named Single-Minute Exchange of Die (SMED).By later Toyota Production System accounts, press die-changeover times fell from hours to an average of around three minutes by the early 1970s, which let Toyota run batches small enough that a defect surfaced within the same shift instead of being buried in a week's worth of parts. The precise plant-by-plant sequence is disputed — historians differ on how much credit belongs to Shingo personally versus Toyota's own engineers — but the order-of-magnitude time reduction and its role in enabling just-in-time, small-lot production are well corroborated across Toyota Production System literature.
2. 1985Haier (Zhang Ruimin)Home appliancesMonths into running a near-bankrupt Qingdao refrigerator collective, Zhang Ruimin took a customer's complaint seriously enough to inspect the warehouse and found 76 refrigerators with quality defects — roughly a fifth of a batch. Rather than discount them as seconds, the normal practice at a time when refrigerators were still a scarce, expensive good in China, he had the workers who built them line the units up in the factory yard and personally smash them with sledgehammers, in front of the entire workforce.Haier reached profitability the following year, won China's first national quality gold award for refrigerators in 1988, and grew from a collective factory on the edge of closure into one of the world's largest appliance makers; one of the original sledgehammers is preserved as a museum artifact. Each destroyed fridge was reportedly worth what an ordinary factory worker could not easily earn back in a year or more — a loss the near-broke plant felt directly.
3. 2002Virginia Mason Medical CenterHealthcareAdopted the Toyota Production System for clinical flow — smaller patient batches, standard work, andon-style stop-the-line for safety signals.Became the reference case for lean healthcare, with sustained gains in safety metrics and capacity.
4. 2010EtsySoftwareContinuous deployment: tens of small production deploys a day, each trivially attributable and reversible, replacing feared release nights.Codified the DevOps norm; industry research (DORA) has since found the highest-performing teams deploy most often with the lowest failure rates.

what breaks in transit

• Small batches with an expensive setup step is just paying the setup more often — sequence matters: changeover first, then batch size.
• A batch of one with no automated check behind it surfaces defects at the customer.
• Lean rituals copied without the stop-the-line authority produce the ceremony and none of the feedback.

adjacent plates

• 05The handoff
• 12The standard box