You might need to model a business to understand its structure and dynamics, to ensure that all stakeholders have a common understanding of the organization, and to derive system requirements to support the organization.
Software engineering techniques can be translated and used for business modeling.
Depending on the character of the organization, as well as the context of the project, you may find yourself employing rather different scenarios of business modeling.
Software requirements derive, in large part, from models of the business.
Rational Software's design tools support business modeling.