To implement, reorganize, or improve a maintenance department or global maintenance management implementation in an organization, it is necessary to have a good diagnosis of the existing problems before the start of implementing a new maintenance design.

This chapter presents a maintenance diagnosis state model that helps to identify what is good, weak, bad, and critical in an organization at the maintenance level.

The holistic diagnosis model presented is based on questionnaires that must be filled out by people who have knowledge in the maintenance area and, even in a big organization, they take only a short time to be filled out.

After this step, the diagnosis model gives a global maintenance state through a radar map and several reports that indicate what is good, less good, and bad in the organization, and also suggest solutions to the identified problems.