01 Company claim
The documented mechanism
Toyota describes TPS as resting on two pillars. Jidoka, 'automation with a human touch', means a machine stops automatically, or an operator pulls a stop cord, when an abnormality is detected, and the andon board lights up to call for help. Just-in-Time means making only what is needed, when it is needed, in the amount needed, with each process pulling parts from the one before it. Toyota is explicit about automation: work should first be done thoroughly by hand and improved through kaizen, removing waste, inconsistency and overburden (muda, mura, muri). Only then should abnormality detection be built into machines.
02 Kept apart from the practice
Reported outcome
Self-reported by Toyota: the company calls the continuous pursuit of the two pillars the 'wellsprings' of its competitive strength. No metrics are given on this page.
03 Read before copying
Confounders and limits
Toyota's results come from decades of cumulative capability, supplier relationships and workforce development that the page describes as built over generations. A single practice can't be credited with them. The page is a corporate philosophy statement, not an evaluation.
04 Over time
Known revisions, reversals or failures
No documented revision found in the sources reviewed. The page says TPS keeps evolving through ongoing kaizen. Criticism and incidents involving Toyota exist in the wider record, but no source for them was reviewed here, so none is asserted.
05 Editorial interpretation — not a company claim
WeCaseStudy interpretation
WeCaseStudy interpretation: this is a manufacturing source. It is linked to build-buy-outsource only through one documented principle: stabilize and improve a process manually before automating it. For a small company that suggests staying on manual_status_quo until the process is understood and repeatable, and only then building automation. This mapping is an analogy, not something Toyota says about software or vendors.
06 What transfers
Adaptation boundaries
A small company should not treat stop-the-line authority or Just-in-Time as cheap to adopt. Both depend on fast response to abnormalities and on synchronized suppliers, which Toyota describes as linking all plants. The page doesn't address buying versus building tools or outsourcing, so don't cite it for those decisions.
Claims and their sources
Each material claim has its own type, source, location and review state. A documented policy is not proof that everyone follows it; a vendor describing its own product is vendor-reported.
Cite this record
We Case Study. "Toyota: Toyota Production System: jidoka (stop on abnormality, including the operator stop cord and andon) and Just-in-Time; machines built only after work is done thoroughly by hand and improved". Decision Lab practice record, version 1. https://wecasestudy.com/decision-lab/practices/toyota-tps-jidoka-manual-first
Please cite the original company sources listed above for the facts themselves; this record is a structured, scoped summary of them.
