26
Step 7: Determine Repeatability and Reproducibility
Objective:
Determine the amount of variability in a set of measurements taken on a
single measurement instrument that can be attributed to the
measurement instrument itself (repeatability) and to the entire
measurement system (reproducibility).
Process:
Completely randomize the (n) samples and (k) operators to
determine what the measurement order will be for the first run.
For example- If there are 3 samples and 2 operators, one possible
random order might be as follows:
Measurement
k = 2
n = 3
Order
Appraiser
Sample
1
B
1
2
B
3
3
A
2
4
B
2
5
A
3
6
A
1
Table 2. Example Measurement Order
Repeat the randomization process for each of the subsequent runs.
Have the operators measure the samples in the measurement order
which was just determined. The engineer should read and record
the data so that the data value remains hidden from the operator.
NOTE: Try to be sure that the operators do not know each other’s
readings either.
