FREE Lean Six Sigma Black Belt Certification Prep Questions and Answers
What guidelines should you follow while choosing a sample?
The sample size must be calculated scientifically using methods that account for standard deviation or the population's current error rate.
SEM stands for?
The standard deviation of averages, abbreviated SEM or Standard Error of Mean, is calculated by dividing the population's standard deviation by the square root of the sample size.
In terms of Repeatability(?r) and Reproducibility(?o) variation, what is Gage Variation(?m)?
ơm = √(ơr2+ ơo2) where ơr = Repeatability or Equipment Variation ơo = Reproducibility or Appraiser Variation
Which of these tasks ought to ideally be completed first when implementing a Measure?
The first task at a measure stage is checking resolution.
Which of the following is not a continuous data capability index?
Process Performance is not a means of measuring a continuous data capability index.
Which of these is the most crucial antecedent to the calculation of capability?
The most crucial item to complete before performing any Measure computations is process stability.
SPC stands for?
Every measurable phenomenon is a statistical distribution according to SPC, or statistical process control, meaning that every set of observed data is a collection of effects from a set of unidentified common causes.
You normally use the following tool to scope a project during the Measure stage:
The project's best available scoping tool is SIPOC.
What GRR percentage must be exceeded before the gage needs to be replaced?
% GRR = 100 * ơm /Tolerance % % PV = 100 * ơp /Tolerance % ndc = 1.41 * PV/GRR If %GRR > 30%, gage needs to be replaced.
How is Total Process Variation (t) expressed in terms of Gage (m) and Part (p) Variation?
ơm = Gage Variation ơp = Part Variation ơt (Total Process Variation) = √(ơm2+ ơp2)
When is the Mean off-center?
The mean is not centered if Cpk > Cp. Mean is centered and process is accurate if Cpk = Cp.
Who is the process expert who rates the samples as acceptable, unacceptable, defective, etc.?
A Master Appraiser is the title given to the process expert who rates the samples.
Which chart type should you use when the sample size varies and each sample could include several occurrences of the specified condition?
When sample sizes are variable and each sample could contain more than one instance of the specified condition, a U chart is acceptable. These control charts are the ones that handle attribute data the best.
What is the equation used to determine Process Capability?
Cp = (USL-LSL)/(6 * ơ), with USL – LSL representing the Process Tolerance.
The GRR is typically 42% in a Measurement System Analysis activity, with Gage Variation and Part Variation each contributing equally. How would you respond?
The study needs to be explored because part variation is present.
Once you know the values for Cpl and CPU, how do you calculate Process Capability Index (Cpk)?
The difference between Cpl and Cpu is called the Process Capability Index, or Cpk.