Statistical Process Control (SPC) is more important than ever. Standards such as SQF and BRC have mandated that testing procedures and practices provide a statistically robust measure for compliance with requirements.
Non-conformances for lacking SPC implementation are on the rise. Our quick quiz below will test your knowledge and explain some key concepts of SPC.
#1 A standard deviation is a key measure of spread in statistics. Which statement below is correct?
The answer is 2 – .3% of data falls outside of 3 standard deviations from the mean
0.15% of the data will fall above 3 standard deviations above the mean and 0.15% of the data will fall below three standard deviations below the mean.
#2 The Process Capability Index is an important concept in SPC, what lettering is used to denote it?
The answer is 3 – Cpk
#3 A normal distribution is critical to SPC. Which of these graphs is a normal distribution?
The Answer is 4.
Key features of the normal distribution:
- Symmetrical shape
- Mode, median and mean are the same and in the centre of the curve
- Only one mode
- Most of the data are clustered around the centre
#4 Which of the following is a sign of Special Cause Variation (SCV)
The answer is 1 – Nine (or more) points in a row that are on the same side of the mean is an indication of Special Cause Variation (SCV)
The others answers either need a greater run of points to indicate SCV or are not an indication of SCV.
#5 Which of these statements is NOT true of an R Chart
The Answer is 3 – Requires a small amount of data is false
An R chart actually requires a large amount of data. Multiple tests are required for each scheduled test. This is so a range can be established and then plotted for each scheduled tests.
Could your business need assistance with SPC?
Our full Statistical Process Control Training Course is delivered on-site for the whole team, allowing everyone to have the knowledge they need to comply with your standard. Read more about the course here.
Call us on 1300 73 71 93 (option 1) or contact us at firstname.lastname@example.org to organise a quote.