Disclosed herein are methods and systems for semiconductor fabrication. In one embodiment, a method for fabricating semiconductors utilizing a semiconductor fabrication system includes performing a semiconductor fabrication process on a first lot of unprocessed semiconductor substrates with a semiconductor fabrication equipment unit to form a first lot of processed substrates and communicating processing data regarding the first lot of processed substrates from the semiconductor fabrication equipment unit to a just-in-time (JIT) module of the semiconductor fabrication system. The method further includes determining a processing priority of the first lot of processed substrates and a processing priority of a second lot of unprocessed substrates at the JIT module and scheduling removal of the first lot of processed substrates from the semiconductor fabrication equipment unit and delivery of the second lot of unprocessed substrates to the semiconductor fabrication equipment unit by the JIT module based on the processing data and the priority of one or both of the first lot of processed substrates and the second lot of unprocessed substrates.