That means exploring the algebra behind the problem to see if I can "solve" for this factor directly. I often see problems on the forum that reduce to something like y=x+0.1*x +k, and the user wants to solve for x using Goal Seek. Of course, in a simple case like this, it is relatively easy to solve for x directly and avoid Goal Seek. My suggestion to step away from Excel is just that, step away from Excel, write out the problem algebraically, and see if it is possible to solve for your "factor" without using Goal Seek. What you describe looks something like y=sum(factor*revenues)-sum(costs). If it is that simple, factor could be easily solved for directly.