• Each candidate block(s) and stack(s) will be assessed using the weighted sum of its criteria and penalty of the block/stack's job category :

• Block/stack with the lowest score will be chosen as target block/stack

Assessing Candidate Block

• Carry in block

  • Candidate block: the top block on the arrival stack

  • Criteria:

• • Penalty

• Carry-out block

  • Candidate block: the block(s) that is ready to send to the handover stack

  • Criteria

• • Penalty

• If the expected processing duration of the target block > estimate time remaining until the upstream process is blocked, add the penalty to the carry-out block

  • In case (a), the penalty will not be given to the carry-out block

• Reason: minimize the possibility of the upstream process being delayed

• Reposition block

  • Candidate block: block with the three shortest times remaining before overdue

  • Criteria

• Penalty

  • The penalty score is similar with carry-out candidate block

Assessing Candidate Stack

• Carry-in stack

  • Candidate stack: every available (not on maximum capacity) buffer stack -> to place block from arrival stack

  • Criteria

• Carry-out stack

  • Candidate stack: every available buffer stack that is not the current stack of the target block

  • Criteria

• Reposition stack

  • Candidate stack: every available buffer stack to place block(s) on top of target block that will be repositioned

  • Criteria