(2) justifications. Question 4 ABC Precision Engineering embraced six sigma approach into their metal stamping process. The quality department has collected statistical process control (SPC) data and determined that the mean is 30.03 and the standard deviation is 0.15. Customer required specification is 30.00+ 0.5 mm. Hence, the actual process is considered as more stable. (a) A stable process may not be capable. Comment about this statement and provide TWO [4 Marks] (b) Assume that the measurement is normally distributed. Sketch the distribution curve of the process. The diagram should include the following information: [8 Marks) Targeted mean = ud Upper Specification Limit = USL Lower Specification Limit = LSL Process mean = up Process standard deviation = 0 Sigma shift (ud-up) c) Calculate the process capability index (Cp, Cpk) of the process. Comment on the process capability. [8 Marks] Given: USL - LSL 60 Cpk = min USL- u-LSL 30 30 USL = Upper Specification Limit LSL = Lower Specification Limit Note: Assume that the population mean, u is equal to sample mean, s