Minimize congestion

To minimize congestion, you may want to:

By breaking your main objective into these smaller goals, you significantly increase your likelihood of success. Not all of these goals make sense for every type of terminal, however. For example, minimizing the number of straddles in an area only makes sense for straddle sites, and beginning with a goal of minimizing the number of other types of CHE in an area is not an effective way to minimize congestion without negatively impacting operations in other ways. The following table provides a basic guideline as to which goals you may want to use based on the CHE type you are using in your Expert Decking ranges:

 

ASCs

RTGs

Straddle Carriers

Accept longer travel distances (on page 1)

 

Improve distribution (on page 1)

 

Improve yard utilization (on page 1)

Minimize the number of Straddles in an area (on page 1)

 

 

Minimize rehandles (on page 1)

Minimize TZ occupancy

 

 

The topics in this section each list some penalties you might use to implement one of these goals where recommended above. If your CHE type is not listed within a goal topic, it is possible that pursuing that goal may not be very useful to minimize congestion in your particular operations.

 

Accept longer travel distances

Situations it can prevent: This prevents CHE underutilization or congestion due to concentration in a particular area of the yard.

CHE Type: ASCs

Penalties to Use: TIMDIS (on page 1), TIMNXT (on page 1), TIMTHN (on page 1), TIMTHS (on page 1).

Other Configuration to Use: You may also want to keep the values of penalties that penalize travel distance low to avoid counteracting these penalties (see Minimize overall travel distance).

Conflicting goals: Minimize overall travel distance, minimize unladen travel distance.

CHE Type: Straddle Carriers

Penalties to Use: SLTHGT (on page 1), SLTTIR (on page 1), STKREH (on page 1), TIMTHN (on page 1), TIMTHS (on page 1).

Other Configuration to Use: You may also want to keep the values of penalties that penalize travel distance low to avoid counteracting these penalties (see Minimize overall travel distance).

Conflicting goals: Minimize overall travel distance, minimize unladen travel distance.

 

Improve distribution

Situations it can prevent: Improving distribution can reduce CHE congestion by preventing fetch CHE queueing.

CHE Type: ASCs

Penalties to Use: BLKFUL (on page 1), ROWDBV (on page 1), ROWDTH (on page 1), ROWUNV (on page 1)(for cantilever only).

Other Configuration to Use: You may also want to keep the values of penalties that penalize travel distance low to avoid counteracting these penalties (see Minimize overall travel distance). The Yard Segregation Factor can also help with this goal.

Conflicting goals: Minimize overall travel distance, minimize congestion (on page 1).

CHE Type: RTGs

Penalties to Use: BLKDWL (on page 1), BLKFUL (on page 1), DISTSF (on page 1), DISTSL (on page 1), FCTRND (on page 1), ROWDBV (on page 1), ROWUNV (on page 1).

Other Configuration to Use: You may also want to keep the values of penalties that penalize travel distance low to avoid counteracting these penalties (see Minimize overall travel distance). The Yard Segregation Factor can also help with this goal.

Conflicting goals: Reserve special slots, keep stacks unmixed.

 

Improve yard utilization

Situations it can prevent: Improving yard utilization can reduce CHE congestion by spreading the work to be done throughout the yard while also reducing decking failures by providing more options for container decking.

CHE Type: ASCs

Penalties to Use: BLKFUL (on page 1), ROWDBV (on page 1), ROWDTH (on page 1).

Other Configuration to Use: You may also want to keep the values of penalties that penalize travel distance (see Minimize overall travel distance) low to avoid counteracting these penalties.

Conflicting goals: Minimize congestion (on page 1), minimize rehandles (on page 1), minimize unladen travel distance.

CHE Type: RTGs

Penalties to Use: ROW40B (on page 1), STK45S (on page 1), TIMTHN (on page 1), TIMTHS (on page 1).

Other Configuration to Use: You may also want to keep the values of penalties that penalize travel distance (see Minimize overall travel distance) low to avoid counteracting these penalties. If you use PR-TT and see many decking failures due to transfer zone congestion, you may want to consider changing the XPS setting EDLSTT (on page 1) to Y.

Conflicting goals: Minimize overall travel distance, minimize truck turn time, minimize rehandles (on page 1), minimize unladen travel distance.

CHE Type: Straddle Carriers

Penalties to Use: HGTCHS (on page 1), ROW40B (on page 1), SLTHAZ (on page 1), STK45S (on page 1), TIMTHN (on page 1), TIMTHS (on page 1).

Other Configuration to Use: Minimize your use of stack status for non-essential blocking. You may also want to keep the values of penalties that penalize travel distance (see Minimize overall travel distance) low to avoid counteracting these penalties.

Conflicting goals: Minimize overall travel distance, minimize truck turn time, minimize rehandles (on page 1), minimize unladen travel distance.

 

Minimize number of Straddle Carriers in an area

Situations it can prevent: By minimizing the number of Straddle Carriers in an area, you can avoid situations where one Straddle would block another and where congestion could prevent Straddle Carriers from taking the most direct routes to their destinations.

CHE Type: Straddle Carriers

Penalties to Use: ROWIMM (on page 1) and TIMRD2 (on page 1)

Other Configuration to Use: You should also use large, general allocation ranges, keep Straddle Carriers with their rehandles, and consider diminishing returns on productivity.

Conflicting goals: Utilize idle CHE, Keep stacks unmixed, Minimize truck turn time, Minimize overall travel distance, Minimize unladen travel distance.

 

 

Minimize rehandles

Situations it can prevent: This prevents situations where too many CHE are occupied with rehandles to move containers in a timely manner, reduces the need to rehandle multiple containers for a single target move (which can also reduce truck turn time), and increases inventory accuracy for manned terminals by reducing the potential for human error while rehandling.

CHE Type: ASCs/RTGs

Penalties to Use: STKFCH (on page 1), STKPFH (on page 1), STKPFL (on page 1), STKPFM (on page 1).

Conflicting goals: Improve yard utilization (on page 1), minimize overall travel distance, maximize twinned or paired moves, Reserve special slots.

CHE Type: Straddle Carriers

Penalties to Use: SLTHGT (on page 1), STKFCH (on page 1), STKFET (on page 1), STKMIX (on page 1), STKMTY (on page 1), STKREH (on page 1).

Other Configuration to Use: In addition to the SLTHGT penalty, set your maximum stack height to include a hard constraint and avoid fringe cases where setting SLTHGT may be insufficient.

Conflicting goals: Improve yard utilization (on page 1), Reserve special slots.