Coordinated Inbound and Outbound Cargo-Flow Planning for Breakbulk Terminal Operations Under a Schedule Adjustment Budget

Breakbulk terminals coordinate cargo receipt, temporary storage, and receiver pickup under daily planning limits and recorded inbound dates. This study develops a lot-level cargo-flow model with a quantity-based schedule adjustment budget. Primary optimization minimizes peak end-of-day inventory, while quantity-weighted completion selects representative schedules. Fixed lot-level ledger reconciliation preserves service requirements. In the 100-lot Case C under 90th-percentile (P90) planning limits and flexible pickup, reallocating 0.595 scaled quantity units restores model feasibility. Relative to this minimum-repair benchmark, unrestricted optimization reduces end-of-day peaks by 70.3% under same-day availability and 48.6% under Lag-1. Target-constrained optimization places the respective required adjustments at 11.72% and 14.17% of inbound quantity within stated tolerances. Across 18 joint planning-limit scenarios, minimum peaks range from 0.207 to 10.504 units under same-day and from 15.470 to 22.326 under Lag-1. Parent-set, closed-cohort, indivisibility, and pickup-window tests show that the results depend on cargo selection and operating assumptions. The framework quantifies the schedule adjustments required to meet inventory targets, providing a basis for evaluating the trade-off between inventory reduction and plan stability.