ITIL Version 5 gives you two models for making things better, and the difference between them comes down to one question. Are you improving within your ITIL Value System, or transforming the value system itself? The Continual Improvement Model (CIM) is for the first. The Transformation Model is for the second. Pick the wrong one and you either over-engineer a small fix or under-power a major change.
The Continual Improvement Model is a high-level, repeatable guide for ongoing betterment. It works through familiar questions, such as what is the vision, where are we now, where do we want to be, how do we get there, did we get there, and how do we keep the momentum. It applies at any level of complexity as long as you adjust the steps to fit. It is the right tool when you are improving how the existing system performs.

Fig. 2.3. ITIL Continual Improvement Model, PeopleCert
The
Transformation Model, by contrast, is built for
changing the system itself: the
operating model, the structure, the relationships, and the way value is created. It brings the heavier machinery, with four layers (governance, positioning, execution, learning), twelve stages, twenty-four steps, and context-specific execution patterns, because system-level change carries more uncertainty, more stakeholders, and more ways to fail. We cover that structure in detail in our
guide to the ITIL Transformation Model.

Fig. 3.3. ITIL Transformation Model, Twenty Four Steps, PeopleCert