According to the Education Hub on the Pennsylvania Department of Education website:

Much research has been conducted as to what makes a great school. There are many intangible components. However, research supports the notion that great schools and school systems tend to have six common elements:

1. Clear Standards
2. Fair Assessments
3. Curriculum Framework
4. Instruction
5. Materials & Resources
6. Interventions

In fact, PDE even created an illustration:



However, the more time I spend looking at that image, the more time I spend thinking about increasing student achievement, I tend to see this: