Let’s return to the example of salaries for university professor. When a CP plan is implements, pay raises are determined in part or wholly based on performance. For example, two assistant professor may be hires at the same time as the same salary level (เช่น &75000). If one of them outperformance the other year after year for year for several year, then eventually the better performing assistant professor may make $11000, which may be a higher level of pay than most associate professor make. This is because every year this assistant professor receives a substantial salary increase ,part of which may be added to the base salary, base on her outstanding and research performance .