It might help to view this graphically. Remember from the unit on capability that a Cp value of 1 means that the process spread could just be contained within the specification limits. A value of 2 means that the process spread could fit within the specification limits twice, and a value of 3 would mean that it could fit three times. This is shown on the image below.
The Cp value of 1.15 for the process tells us that the overall process spread could potentially fit within the specification limits. However, the value is lower than many organisations would require, since it doesn't allow much margin for error. This can be clearly seen from the image below.
