Trying to clarify the problem.
Imagine a factory that produce soccer balls; if you produce 1 ball, it will take a certain amount of game cycles. For sake of simplicity, let's say it could take between 5 and 15 cycles (depending from various conditions, like number of workers, quality of workers and so on). Once you make a certain amount of soccer balls, the process is considered done.
Now, I want to display a value in percentage for costs, and a value of defective balls made. with "cost", I am trying to display how much did I spent (materials, workers wage and so on), at the moment. The number in currency is self esplicative, but I believe a percentage value could help to know if you are using too many workers, or burning too many resources, resulting in a waste of money.
To calculate the percentage of defective is relatively simple, since every X amount of time, when I refresh, I can check the balls produced against the defective ones, and the result should be
Total produced * 100 / defective = percentage of defective.
But for the costs, things are different; so I was planning to use the number of cycles to calculate percentage for costs:
cycles * 100 / current costs = percentage of costs
Would this be considered correct? Since the number of cycles for a whole batch of balls may vary slightly, this may represent that when there are less cycles, it means that you spent less money, henche the percentage will be smaller.