Step 1: Identify the core problem in the scenario.
The factory pays all workers the same wage regardless of how much they individually produce. Workers who produce more get no extra reward, so there is no financial reason to work harder. This naturally leads to a decline in productivity.
Step 2: Connect this to Taylor's Scientific Management.
F.W. Taylor specifically identified the practice of paying flat wages as a major cause of "soldiering" (deliberate underperformance) among workers. He designed a technique to directly fix this problem.
Step 3: Recall Taylor's wage-related technique.
Taylor introduced the Differential Piece Wage System to create a direct, measurable link between individual output and individual pay. It uses two different wage rates: a higher rate for workers who meet or exceed the standard target, and a lower rate for those who fall below it.
Step 4: Understand how this technique would solve the problem.
If the factory applied differential piece wages, an efficient worker producing above the standard would earn significantly more, creating a strong incentive to perform. An inefficient worker earning less would be motivated to improve.
Step 5: Confirm why the current system is the violation.
By paying everyone the same wage, the factory removes the incentive-performance link that is the very foundation of the Differential Piece Wage System. Efficient workers are penalized (relatively) and inefficient workers are rewarded (relatively), causing overall productivity to fall.
Step 6: State the conclusion.
The technique of scientific management being ignored here is the Differential Piece Wage System, which Taylor designed precisely to reward high output and penalize low output.
\[ \boxed{ \text{Differential Piece Wage System} } \]