1- The mean of a process is 50, and the standard deviation is 2. The company uses statistical control process (SPC) to monitor the process. It uses sample size on 4, and 3 sigma (z=3) control limits. What are the Upper Control Limit (UCL) and Lower Control Limit (LCL)?
a- LCL= 48 and UCL=52
b- LCL = 47 and UCL=53
c- LCL = 49 and UCL=51
d- LCL = 44 and UCL=56
2- If a company narrows the control limits for a process without making any other changes, which of the following will happen?
a- the process will generate more products not acceptable by customers
b- the process will not be stopped even when assignable cause is present
c- the capability index for the process will reduce to a lower value
d- the process will be stopped more often suspecting assignable cause
3- Which of the following is a reason why queues will form even if capacity exceeds demand?
a- there is no variability in average capacity
b- customers do not arrive in a consistent pattern
c- customers arrive in a consistent pattern
d- there is no variability in the arrival of customers