Here's why:
* System: A set of interconnected parts working together for a purpose. This is a concrete noun.
* Systematization: The process of organizing something into a system, the state of being organized into a system. This is the abstract noun form, referring to the concept of organization and structure itself.
While other abstract nouns like order, structure, or organization could relate to a system, systematization most directly captures the specific concept of turning something into a structured system.