piece wage
piece-payment
piece-rate pay , auch: incentive pay

It is contrasted with piece wages, where each job, hour or other unit is paid separately, rather than on a periodic basis.

The ultimate agreement called for a shortened work week, a 12 percent hike in hourly and piece wage rates, and recognition of shop grievance committees in all departments.

The "ideal" form of wages for capitalism, he argued, were piece wages because in that case the capitalist paid only for labour which directly created those outputs adding value to his capital.