Assessments encourage participants to think across boundaries that may exist in the organization. Programmers learn how requirements experts think. Technical people learn how managers think. People on different projects learn how the other parts of the organization think. All in all, the experience helps everyone to feel as if he or she is part of an organization with mutual interests instead of competitors for resources or recognition. This is no small thing.
Nor is thinking across boundaries just a matter of what the other guy is doing. Different parts of the organization may have a certain way of thinking about quality, for example, even if they are doing similar jobs. The give and take of assessments helps them to question their own deeply held assumptions about what works and what doesn’t work and opens them up to other and perhaps better ways to do things.