SPC 考试题目

1) If a process is in a state of statistical control, does it necessarily follow that all of the units of product produced will be within the specifications?
A) Yes
B) No
2) Using the logic underlying the use of 3-sigma limits on Shawhart control charts. If you increase the sample size, how will the control limits look like?
A) Narrower limits
B) Wider limits
3) When taking samples or subgroups from a process, what do you want assignable causes occur?
A) Within the subgroups
B) Between the subgroups
4) A manufacturing process produces 500 parts per hour. A sample part is selected about every half-hour, and after 5 parts are obtained, the average of these 5 measurements is plotted on an x-bar control chart. Is this an appropriate sampling scheme?
A) Yes
B) No
5) What type of error of the following:
5.1) When there is a shift in your process, you found no shift
A) Type I error(alpha)
B) Type П error(beta)
5.2) When there is no shift in your process, but you found shift
A) Type I error(alpha)
B) Type П error(beta)
6) Which chart is more sensitive if your sample size is 5?
A) R chart
B) S chart
7) Should the costs of searching for assignable causes impact the choice of parameters of a control chart?
A) Yes
B) No
8) Is the ARL performance of a control chart a more meaningful measure of performance than the type І and type П error probabilities?
A) Yes
B) No
9) Does putting USL and LSL on a x-bar chart help ensure that parts are meeting Cpk requirements?
A) Yes
B) No
10) Is it alright to shrink USL and LSL down to, say, 70% or 80%, to establish UCL and LCL on a x-bar chart?
A) Yes
B) No
11) If your process is out of control on a x-bar chart, does it mean that the parts do not meet customer spec?
A) Yes
B) No
12) If your process is in control on a x-bar chart, does it mean that the parts meet customer specifications as well as Cpk requirements?
A) Yes
B) No
13) Which sigma to use for calculating control limits in a x-bar chart?
A) σ x
B) σ x-bar
14) How should you establish the sampling plan?
A) Customer requirements
B) Passed-down figures
C) Statistical calculation
D) Technical judgement
15) Where should you use SPC charts?
A) When a mistake-proofing device is not feasible
B) All the critical input variables
C) All the critical output variables
D) All of the above
16) Does putting USL and LSL on a I-MR chart help ensure that parts are meeting customer requirements?
A) Yes
B) No
17) Central Limit Theorem can be applied to plot R chart and S chart.
A) Yes
B) No
18) For the control of process and product, such as peel strength only has lower spec limit, we still need to set Upper and Lower control limit.
A) Yes
B) No
19) In X-MR chart, X0 may be set at some historical estimate of the process mean. If X0 is omitted, then the first MR is not calculated.
A) Yes
B) No
20) One of the advantages of CUSUM and EWMA chart is, they are more sensitive to small shifts, and they are often being used for Attributes.
A) Yes
B) No