The Postal Service tracks three metrics for NPA purposes as an indication of our financial performance. The first is Deliveries per Hour (DPH), which summarizes the effectiveness of productivity improvement efforts. The indicator is relevant, especially as the organization manages a declining volume workload over time with a constantly increasing universal delivery network. The second is Deliveries per Total Work Hours as a percent of the same period last year (SPLY), and the third metric is Controllable Income.
