Which technique of Scientific Management violates Fayol's principle of Equity?

Differential Piece wage System

The Differential Piece Rate System, a technique of Scientific Management, violates Fayol's principle of Equity. Under the Differential Piece Rate System, workers are paid different amounts per unit produced, depending on their output level. Workers who produce more units are paid a higher rate per unit, while workers who produce fewer units are paid a lower rate per unit. Fayol's principle of Equity states that all employees should be treated fairly and equally, regardless of their output level. The Differential Piece Rate System violates this principle by discriminating against workers who produce fewer units, even if they are working just as hard as workers who produce more units.