What steps do you take when you encounter a problem, such as a pen that stops writing?

When encountering a problem like a pen that stops writing, the steps to take include:
sIdentify the problem by asking, “Why did my pen stop writing?”
Make a guess or hypothesis about the cause (e.g., the ink is finished).
Test the guess by checking the ink refill.
If the initial guess is incorrect, formulate another hypothesis (e.g., the ink has dried up) and test that as well.