There is a way to use a developer without replenishment. It was a fairly common method some years ago. That is to use the developer normally for the first few rolls and then begin to increase development times as each successive roll is developed. Typically this increase might be 5 to 10% additional time for each roll. As an example only, if the development time is say 12m then after the first 2 to 4 rolls increase the time to 12 x 1.1 = 13.2 m, then 13.2 x 1.1 = 14.5m, then 14.5 x 1.1 = 16.0m, ... Obviously if you have a large volume of developer the increase might be only 5% per roll and you can process more initial rolls before you start correcting the times. The system works just as well as replenishment does. This is the system that Agfa used for their Atomal developer.