Definition
The few metrics that provide long-term direction during a transformation (typically covering quality, delivery, cost or productivity, and people), used to judge whether improvements are accumulating in the right direction rather than as monthly appraisal scores. From published works, not a textbook measurement definition.
In detail
True North Metrics answer "where are we heading in the long term": few in number, unchanged for years, demanding an improvement magnitude large enough to require changing how things are done—for example, halving defects or cutting Lead Time to a fraction of the original. They overlap with Core Value Drivers but differ in emphasis: Core Value Drivers are the unified scoreboard and Annual Objectives definition, while True North Metrics are the compass for the transformation direction. The two should not each have their own separate set that conflicts with each other.
Example in practice
In the first year of transformation, the plant sets True North Metrics as external defect rate, on-time delivery, inventory turns, and employee turnover, placed on the first page of the Monthly Operating Review. Mid-year, a Kaizen project made a single month's profit look good but raised inventory, and was stopped based on the True North direction.