work center in the job’s routing is below its workload norm; otherwise, the job is retained in the pre-shop pool. The full periodic release procedure can be formulated as follows: A priority value is determined for each job in the set of jobs in the pool. J The job with the highest priority is considered for release first. If job processing time at the operation in its routing corrected for work center j’s pij ith – position together with the current corrected workload at work center corresponding to i s – operation fits within the workload norm at this work center, i that is , with being the ordered set of operations in the routing of job then the job is selected for Rj j, release, i.e. removed from and its load contribution is included, J, that is . Otherwise, the job remains in the pool and its processing time does not contribute to the work center load. If the set of jobs in the pool contains any jobs that have not yet been considered for release, J then return to Step 2 and consider the job with the next highest priority. Otherwise, the release procedure is complete and the selected jobs are released to the shop. 2.1.2 The Continuous Release Time Element of LUMS COR In addition to the above periodic release mechanism, LUMS COR also incorporates a continuous workload trigger. If the load of any work center falls to zero, the first job in the pool sequence with that work center as the first in its routing is released from the pre-shop pool irrespective of whether its release would exceed the workload norms of any work center in its routing. This avoids premature work center idleness or starvation. The workload contribution to a work center
work center in the job’s routing is below its workload norm; otherwise, the job is retained in the pre-shop pool. The full periodic release procedure can be formulated as follows: A priority value is determined for each job in the set of jobs J in the pool. The job with the highest priority is considered for release first. If job j’s processing time pij at the ith operation in its routing – corrected for work center position i – together with the current corrected workload at work center s corresponding to operation i fits within the workload norm at this work center, that is , with Rj being the ordered set of operations in the routing of job j, then the job is selected for release, i.e. removed from J, and its load contribution is included, that is . Otherwise, the job remains in the pool and its processing time does not contribute to the work center load. If the set of jobs J in the pool contains any jobs that have not yet been considered for release, then return to Step 2 and consider the job with the next highest priority. Otherwise, the release procedure is complete and the selected jobs are released to the shop. 2.1.2 The Continuous Release Time Element of LUMS COR In addition to the above periodic release mechanism, LUMS COR also incorporates a continuous workload trigger. If the load of any work center falls to zero, the first job in the pool sequence with that work center as the first in its routing is released from the pre-shop pool irrespective of whether its release would exceed the workload norms of any work center in its routing. This avoids premature work center idleness or starvation. The workload contribution to a work center
Thurer_et_al_POM_2015_Sequencing.docx