A keystone is “the architectural piece at the crown of a vault or arch which marks its apex, locking the other pieces into position.” It may also be defined as an anchor, “or central cohesive source of support and stability or a central building block.”

Requirements are the keystone of a successful project implementation. Imagine an arch. On one side of the arch you have the business stakeholders and users, and on the other side you have the solution delivery teams. The requirements bind the two sides together and keep the arch from falling apart.

Below is a rough illustration of the composition of the requirements “keystone” that joins the problem (business) domain to the solution domain.

The keystone metaphor is one that has helped me on a few occasions to describe the importance of requirements and their role in enabling project success. I hope a few of you will be able to make use of it as well.

I’d be interested in hearing of any similar types of  metaphors or analogies you might use to describe the role and importance of requirements and business analysis.

Keystone image by MMGoode