An inventory tracking system and method for use in semiconductor manufacturing provide for generating a priority score that determines the order in which lots of substrates should be run. The priority score is generated using an algorithm that takes into account external lot priority considerations, inventory factors in the manufacturing facility, and processing tool capability factors. The processing tool capability factors include factors related to tool status and tool restrictions and the inventory factors include factors related to line balance, WIP (work-in-progress) forecasts and various downstream considerations. The priority score is generated dynamically and displayed at each processing operation for each lot that is queued for processing at the indicated operation. Various algorithms are used and different weights are assigned to many factors in calculating numerical values for several factors that combine to produce the priority score. The generated priority score can be tool-specific or module-specific.