Cumulative Sum (CUSUM) control chart conceived by[13] and which have been developed by many authors [5],[3],[8],[10],[9] have been proposed as an alternative to Shewhart charts because it gives a tighter process control than classical quality control schemes such as Shewhart scheme. This is because they detect small shifts in the process level more quickly as they give an early indication of process change and they are more meaningful graphically as they point out areas needing attention.