One of the recommended approaches to problem solving is the IDEAL model, from Bransford and Stein’s book Ideal Problem Solver. Their model addresses a problem in simple stages. After you implement a solution, you can revisit it to examine its quantifiable results and see what needs to be tweaked.
Problem Solving Stages:
Identify the issue
Define the obstacles
Examine your options
Act on an agreed course of action
Look at how it turns out, and whether any changes need to be made.