To choose the best alternative, cost-benefit analysis of the different options are necessary. It can be challenging to quantify the effect of the various alternatives. It requires the ability to understand the complete picture and to assess the overall effect of each option.
Six Sigma focus on gathering neutral information and fact-based decisions. You learn practical statistical tools you need to understand the problem, the current situation and analyze root causes you need to improve to reach the desired situation. The improve phase of Six Sigma identifies different solutions, and calculate the effect of the different alternatives. To make the right decision it is important to evaluate pros and cons and calculate the cost-benefit effect of the various alternatives. It does not need to be 100% correct, 90% is usually more than enough to make the right decision. Six Sigma includes prioritizing tools and is well suited for cost-benefit analysis.