It is widely recognized that a number of factors are important in achieving successful Six Sigma Black Belt projects. In particular:

  • Leadership support
  • Project selection
  • Black Belt candidate selection

Much has been written about leadership support and project selection, not as much on candidate selection. Many Six Sigma companies would benefit from knowing more about identifying the critical success factors associated with candidate selection. To this end, a recent study started with psychometric tests of a group of Black Belt candidates carried out ahead of their four weeks of DMAIC (Define, Measure, Analyse, Improve, Control) training. Then the results of these tests were then compared with the extent to which the Black Belt candidates successfully applied the training to their improvement projects.

A good degree of correlation between the psychometric tests and the project success was obtained, which is all the more remarkable when considering how much other factors such as organizational support and project selection could influence the results.

Psychometric Tests

Psychometric profiles were conducted for 32 Black Belt candidates ahead of two waves of training. The profile was split into three areas – thinking style, occupational interest and behavioral traits. The candidates from the same corporation were based in a wide range of counties in Europe and the Americas including Scandinavia, Eastern Europe, Ireland, USA, Mexico and Brazil.

The same instructors were used on both waves and the instructors perceived that the second group were more difficult to train than the first and they also made less progress on their projects. It could later be seen that this perception was consistent with differences between the waves in the significant psychometric factors.

Project Progress

The instructors independently measured the Black Belt candidates’ progress on their Six Sigma projects through the extent to which the candidates were applying the DMAIC tools and methodology to their projects at the end of the final week of training. An evaluation of this measurement system was carried out as it was believed that the scoring of the Black Belt project could be too subjective and too inconsistent to enable any conclusions to be drawn from the scores. No significant difference was seen in the scores of the three trainers. However, the measurement system contributed 27.65 percent of the total variation in the study.

Statistical Conclusions

The conclusions of the study were that:

  • About 40 percent of the variation in project progress could be related to the differences in psychometric characteristics of the Black Belt candidates.
  • The psychometric factor that provided to be most significantly correlated to project progress was people service. The more candidates were interested in roles that help others, the better their progress on their projects. There was a correlation of 0.474 between project success and this factor alone.
  • Other factors that were related to project progress were:
    • Technical – This has a negative coefficient indicating the more interest that the candidate had for a technical role, the slower progress they made with their project.
    • Attitude – A positive attitude made better progress.
    • Independence – The more independently the candidate acted the slower the progress.
  • Wave 1 made greater progress on their projects and had higher scores on people service which confirmed the trainers’ impressions.
  • There is no significant correlation between project progress and the three summary scores for each of the psychometric categories – thinking style, occupational interest and behavioral traits.

Practical Conclusions

The study illustrates that psychometric testing in assessing Black Belt candidates could be applied effectively. However, in the absence of psychometric testing, it is clear that candidates should not be selected so much for their ability to work independently or for their technical ability, but more for their ability to consult with and assist others. Selecting candidates on that basis would increase the likelihood of them being successful in getting Six Sigma projects implemented and on time. It also appears that these people are better suited to ensuring their projects are properly scoped and will be able to make progress by involving others only when necessary, rather than requiring large amounts time from others to be allocated to the project.

Further consideration needs to be made of how national and regional cultures could affect these results. The psychometric characteristics that have been identified may not suit all national cultures. For example eastern European candidates scored lower on people service but maybe there are different psychometric factors that would be correlated to more successful projects in their national cultures.

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