Minitab provides different ways you can randomize the runs for your gage R&R Study or your Wheeler's EMP study. The AIAG recommends a study with randomization of the runs within operator.

To create a data collection worksheet for either type of study, choose . Use the options for the analysis to specify the randomization method.

Suppose you have 10 parts, 3 operators, and 2 replicates (trials), for a total of 60 runs, and you want to randomize runs within operator. Operator 1 measures the first 10 parts, before Operator 2 measures the parts.

After each operator measures the first replicate, Operator 1 begins the second replicate and so on.

C1 | C2-T | C3-T |
---|---|---|

RunOrder | Parts | Operators |

1 | 9 | 1 |

2 | 6 | 1 |

3 | 8 | 1 |

4 | 2 | 1 |

5 | 7 | 1 |

6 | 10 | 1 |

7 | 3 | 1 |

8 | 1 | 1 |

9 | 5 | 1 |

10 | 4 | 1 |

… | … | … |

31 | 1 | 1 |

32 | 2 | 1 |

33 | 10 | 1 |

… | … | … |

60 | 5 | 3 |

Replicate 2 is in a different order from replicate 1 because of randomization.

When you choose to also randomize operator sequence, any of the operators can be assigned to their measurements first, any of the remaining operators can be assigned to measure second, and so on. In this case, Operator 3 may be assigned to the first set, Operator 1 to the second set, and Operator 2 to the last set.

Suppose you have 10 parts, 3 operators, and 2 replicates (trials), for a total of 60 runs, and you want to randomize all runs. Each time you create another worksheet and randomize all runs again, you will have a different run order. Because randomization of all runs encompasses both sets of replicates, an operator may measure the second replicate of a particular part before all parts and operators have measured the first time.

Run 1 is the first replicate of Operator 3 measuring part 9; run 18 is the second replicate.

C1 | C2-T | C3-T |
---|---|---|

RunOrder | Parts | Operators |

1 | 9 | 3 |

2 | 6 | 1 |

3 | 3 | 2 |

4 | 4 | 3 |

5 | 6 | 1 |

… | … | … |

18 | 9 | 3 |

… | … | … |

58 | 5 | 2 |

59 | 8 | 2 |

60 | 2 | 1 |

Suppose you have 10 parts, 3 operators, and 2 replicates (trials), for a total of 60 runs, and you do not want to randomize. The run order is listed sequentially, 1 through 60. The parts are listed in order for each operator, then the entire sequence is repeated for the second replicate.

Rows 1-30 are the first replicate. Rows 31-60 are the second replicate. Each of the three operators measure each of the 10 parts, sequentially for the first replicate, then for the second replicate.

C1 | C2-T | C3-T |
---|---|---|

RunOrder | Parts | Operators |

1 | 1 | 1 |

2 | 1 | 2 |

3 | 1 | 3 |

4 | 2 | 1 |

5 | 2 | 2 |

6 | 2 | 3 |

… | … | … |

13 | 5 | 1 |

14 | 5 | 2 |

15 | 5 | 3 |

16 | 1 | 1 |

17 | 1 | 2 |

18 | 1 | 3 |

19 | 2 | 1 |

20 | 2 | 2 |

21 | 2 | 3 |

… | … | … |

28 | 5 | 1 |

29 | 5 | 2 |

30 | 5 | 3 |

Standard order is the non-randomized order of the runs. If you choose to display the standard order of the runs, it will be stored in C1 and the other columns will be shifted.