Check your current situation and determine priorities for improvement.
Select a set of projects for action based on your available resources and priorities.
Plan each project in order to enhance performance.
Do, implement each project.
I like to see a management system as a portfolio of projects. Please check ISO 9000:2015 definition for management system. Something like:
System to establish a policy, an orientation, a set of priorities. Then, translate these priorities into objectives, into concrete challenges. Then work, transform the organization to meet those objectives.