By exploiting and implementing a fluid communications infrastructure along the supply line of parts, manufacturers, labor and customers, Toyota could maintain smaller inventories and make rapid adjustments. A quicker response time was now possible and products could be made when they were needed. All of the work could be handled by a wider number of less-specialized workers and design revisions could be made on-the-fly without shutting down production and re-tooling. The result was an immediate surplus of cash (due to reduced inventories) and a sustainable, responsive design and production system—smaller warehouses, faster communications networks, responsive and iterative design revision and products made as they are needed: Just-In-Time.

Dexter Sinister, Just-In-Time (workshop description), 2006 dextersinister.org

Two parallel time-lines: while Japanese industrials had to review their factory practices after the second world war, occidental automotive engineers were also looking reinvent their tools. They primarily needed to reduce costs but were simultaneously looking to expand the flexibility of their processes to be able to adapt to whatever the next car model was going to need. The engineers kept on thinking back to a way in which the production line workers brought micro adjustments to the dies of the hydraulic presses. Small piles of metal rings and washers were inserted in the jaws of the presses or into molds and die.¹ In this way they could adjust the gigantic machines millimeter by millimeter to produce a change in shape, that a last minute modification in the design required.

The just-in-time method has been well at work on every detail of the construction of a car since the beginning of its industrialisation. This is generally called lean manufacturing² and takes examples ―as well as common sense― from Benjamin Franklin's methods for reducing waste in his printing workshop. The later Taylorist theoretician Taiichi Ohno³, credited for inventing JIT, refers to Henry Ford's book "Today and Tomorrow" when asked about the origin of the method. Later, when French engineers were mulling over future processes for building objects as complex as cars in high volume, they knew that "only the last turn of a bolt tightens it—the rest is just movement". This quote is from Shigeo Shingo who documented JIT and detailed it into his Single-Minute Exchange of Die (SMED)⁴ production method. Following this, many operations got to be simplified to a point where only last minute adjustment were needed on the spot.

Men in grey suit at both Renault and Citroën were clearly looking for adjustment tools when starting to use digital geometry... It is not a surprise that fifty years later, in the realm of visual production, handles on a curve are the kind of adjustment tools we use for lean ways to draw a shape.