CHETZO

Description: Introduced for use by N4 Automation sites. Penalty based on occupancy in the transfer zone. While CHEBSY (on page 1) is primarily responsible for managing AGV congestion and discharge distribution, the CHETZO penalty becomes important when the TZ occupancy is high or almost full, as determined by Expert Decking penalty CHETZB (on page 1).When the TZ occupancy is low, the CHEBSY penalty is responsible for counting moves through the TZs. Note that For semi-automated or N4 Automation sites, this penalty only applies to the Handling CHE. CHETZO functions somewhat like a pressure-release valve; CHEBSY manages congestion until occupancy gets high, then CHETZO is applied as needed to release the occupancy pressure.

Applies only to transfer zones that accept the allowed move kind of the container move, regardless of whether the transfer zone is covered by any CHE zones or active CHEs. In addition, if a TZ is completely blocked by a status of either Temp Block or Men Working, TZ Decker fails to deck containers to that TZ.

If a stack block that is configured as Transfer Zone - Straddle has a stack status of Temp Block, N4 Automation considers the following stack blocks also as temporarily blocked:

Its immediate adjacent 40' overhangee or overhanger stack

All stacks beyond the blocked stack block along the accessing direction of the section. However, this requires that you set the Access field of each row of the block to either "A" (Access Ascending) or "D" (Access Descending) in the yard.txt file. You can configure this in the N4 Yard Editor Yard Section form (on page 1).

Therefore, CHETZO applies only for the last TZ_buffer slots of the TZ or when the occupancy of the TZ is larger than its effective or instant capacity (only when (N_occ + N_inv) > (TZ'_capacity - TZ_buffer)).

In addition, Expert Decking considers containers (receivals and deliveries) planned through the TZ, including plans between the truck and the ASC stack, empty chassis and cassettes, TZs fully occupied with parked AGVs, a threshold for empty TPs, and 3 TEU TPs for landside TZs. If the calculated value for CHETZO is a non-zero value, Expert Decking considers the transfer points with empty cassettes in the landside transfer zone (LSTZ) and the unladen chassis are added to the occupancy count when calculating occupancy slots.

For long (3 TEU) external trucks performing gate moves in a LSTZ for an ASC stack, Expert Decking calculates the CHETZO penalty separately for the containers arriving on these long trucks. The CHETZO calculation for long trucks considers the containers at or planned to the TZ and the containers planned through the TZ, but only for TZs with long (3 TEU capable) TPs. Expert Decking uses the Truck Visit on the WI to determine which containers are planned to arrive or depart on the same truck. However, because the WI does not exist yet when decking receival containers, Expert Decking uses the boolean TruckIs3TEU flag for those containers. For more information on configuring long TPs, see Configure long TPs for gate moves in the Navis N4 Automation Configuration manual.

If the calculated value for CHETZO is negative, Expert Decking considers it to be zero (0).

For containers that are too heavy or are tanks, Expert Decking calculates the CHETZO penalty based on direct-exchange TPs only because these containers can only go to direct exchange TPs.

For empties, when you make a gate request most often by B/L, or any other characteristic that may match multiple empties spread over multiple ASC blocks, CHETZO is applied along with CHETZB (on page 1). The TZ occupancy is considered to prevent multiple OTRs being assigned to the same unit from a single block.