Organizations choose to adopt a model for any or all of the following reasons:

Satisfy business goals and objectives

If the current infrastructure and processes are not meeting business goals and directives, adopting a model can refocus the IT organization to meet those goals and objectives.

Requirements are imposed by customer(s)

In an effort to improve efficiency and effectiveness, key customers may direct the IT organization to adopt a model.

For competitive reasons

External customers may only do business with an IT organization that is in compliance with a model.

As a guide (roadmap) for continuous improvement

A model usually represents the combined learning of leading organizations, and, as such, provides a roadmap for improvement. This is particularly true of continuous models.