The first of the five-lean-principles: define value from the customer's perspective. james-p-womack and daniel-t-jones placed this as the starting point of lean thinking in lean-thinking (1996), arguing that all lean efforts must begin by specifying what the customer actually wants.
The Reframing
taiichi-ohno's TPS began with waste — the seven types of muda — and worked to eliminate them. This is a subtractive approach: identify what shouldn't be there and remove it. Womack and Jones inverted the logic: begin by defining what should be there (value), then identify everything that isn't value (waste). The practical effect is the same — waste gets eliminated — but the starting point changes the conversation from "what's wrong?" to "what does the customer need?"
This inversion was aimed at Western managers. Ohno could assume Toyota's workforce understood the customer's requirements implicitly through decades of organizational culture. Womack and Jones could not make that assumption for the diverse organizations they were addressing. By making value definition the explicit first step, they forced the question: "Do we actually know what our customer values?"
Application
In practice, the value principle asks organizations to:
The principle's downstream application in healthcare (patient-defined value), software (user-defined value), and services (consumer-defined value through lean-consumption) all trace from this starting point.