This is a short list I follow when I need some solution to solve problems.

1. What's going on?

Identify the problem

2. What do we know?

Collect data

3. What are the root causes?

Analyze the data

4. What could we do?

Brainstorm, generate solutions

5. What's the best thing to do?

Select solution

6. How do we go about it?

Planning

7. Have we solved the problem?

Implement and test

8. Can we improve on what we have done?

Continue to improve