IDENTICAL PARALLEL B ATCH PROCESSING MACH INES BASED ON ACO MULTI - OBJECTIVE SCHEDULING

In this paper, the Batch Processing Machine (BPMs) and its scheduling problem in a semiconductor wafer fabrication facility (fab) has been focused ,where in there are many BPMs, such as diffusion machines, oxidation machines and dry strip machines. The jobs processed on those machines cannot be batched together unless they use they have the same recipe of those BPMs. As a result, the scheduli ng problem of those BPMs is abstracted as identical PBPM with incompatible job families. In a fab, because most of upstream and downstream machines of the BPMs are non - BPMs, jobs must be batched or split regularly during their fabrication processes. Theref ore, a good scheduling solution of those BPMs is important to efficiently utilize their capacity and satisfy the requirements of their downstream machines to balance the fab - wide workload and achieve better fab - wide operational performance.