Toyota traced jidoka (“automation with a human touch”) back to Sakichi Toyoda’s loom work, which aimed to stop equipment automatically when abnormalities occurred. This idea later became one of the two pillars of the Toyota Production System (TPS), along with just-in-time. Building quality into the process reduced the need to inspect defects at the end.
In the 1930s, Toyota founder Kiichiro Toyoda promoted the idea of making only the needed quantity of parts when they were needed—what he called “just-in-time.” This established a guiding goal for later factory methods, even though Toyota still lacked the tools to run production that way at scale. The concept mattered because it set a cost-and-inventory target for Toyota in a market that could not support huge batches.
Taiichi Ohno later described his first practical steps toward achieving just-in-time as beginning around 1949–1950. Toyota’s own history places key trial-and-error work for TPS foundations in the late 1940s and early 1950s at the Honsha machinery area. These experiments were important because they moved JIT from an idea to shop-floor methods.
In 1950, Eiji Toyoda visited Ford’s operations to study mass production. The visit helped Toyota leaders compare high-volume American methods with Japan’s smaller markets and constrained resources. This contrast pushed Toyota toward a system designed for variety, smaller batches, and tighter control of waste rather than copying Ford directly.
Ohno developed kanban (a card/signboard signal) to control production and replenishment based on actual downstream use—often described as a “pull system.” The goal was to prevent excess inventory by setting limits and tightening them as problems were found and fixed. This made material flow visible and created daily pressure to remove causes of delay and defects.
Toyota’s Motomachi Plant began operations in August 1959 as a passenger-car-dedicated factory, expanding Toyota’s capacity and modernizing material handling and flow. A larger, integrated plant gave Toyota a more demanding environment to refine standardized work, smoother transport, and tighter coordination between processes. This created conditions where JIT and kaizen could be tested and spread more widely.
Toyota’s history describes expanding TPS from the Honsha area to the full Honsha Plant in the late 1950s, with implementation at all plants beginning in 1960. This mattered because TPS stopped being a localized experiment and became a company-wide management approach. Wider rollout also exposed inconsistencies that required more standardization and training.
Toyota reports that a “new kanban management system” was adopted at all plants in 1963, making just-in-time production more feasible in daily operations. Producing and delivering parts according to kanban reduced in-process inventories and forced problems (like uneven work or unclear transport rules) to surface. Solving those problems helped stabilize line performance.
Toyota states that through 1965, kanban was also adopted for retrieving parts from suppliers. Toyota encouraged suppliers to adopt similar techniques, aiming to improve both Toyota operations and supplier operations. This step mattered because JIT cannot work reliably if outside deliveries are unstable or disconnected from actual use.
As Toyota grew, new plants came online in the mid-to-late 1960s, including Kamigo (1965) and Takaoka (1966). Expanding production capacity increased the need for consistent methods to coordinate parts, schedules, and problem-solving across sites. These openings made TPS practices more valuable because complexity rose with scale.
Toyota describes implementing production leveling—equalizing production items and volumes—to avoid overburdening specific processes with extra people or equipment. Leveling supported JIT by reducing sharp swings that would otherwise require buffers of inventory and overtime. In practice, it tied scheduling discipline to daily kaizen work: when variation fell, remaining problems became easier to see and fix.
Toyota’s history notes that introduction of TPS at Toyota Group companies (suppliers) began in the late 1960s. This shift extended kaizen beyond Toyota’s walls, focusing on shared methods rather than only price negotiations. The outcome was a more integrated production network, which is essential for just-in-time to function with low inventory and fast problem response.
Taiichi Ohno at Toyota: JIT and Kaizen implementation (1950–1970)