Good morning,
After I isolated that the cause of a profit decline must be internal, I always use the logic that either revenues must have gone down, cost up or both. I then examine first revenues and costs. If I see that revenues are up (or costs down), I know that this branch is not responsible for the profit decline and can exclude it. Am I right that here the logic is that absolute profits decrease if the absolute change in costs is bigger than the absolute change in revenues?
How do I get a similar framework when I tackle a case where profit margins have decreased and I know its an internal problem? Is it that the percentage increase in cost must be bigger than the percentage increase in revenues? Generally in such a situation I can't say anything if absolute profits have decreased as well?