R01. Carrier coverage must include the package shipping range.
R02. The carrier and selected mode must support the package weight; the package weight must be less than or equal to both the carrier maximum supported weight and the mode maximum recommended weight.
R03. Perishable packages require temperature-controlled transport.
R04. Hazardous packages require hazardous-material certification.
R05. Intercontinental deliveries can only use the flight or shipment transport modes.
R06. Fragile packages cannot be assigned to shipment.
R07. Express packages cannot use shipment.
R08. Packages already delivered do not need a new transport assignment.
R09. Retailer and user regions affect both delivery time and transport price.
R10. Region distance is 0 when the origin region and destination region are the same. Otherwise it is computed as abs(origin distance score - destination distance score) + 1, with an additional network penalty of 2 when crossing between US and non-US regions.
R11. Estimated delivery days formula: retailer processing days + shipping-range distance score + region distance + mode transit days + carrier base delay days.
R12. Weekend-enabled users receive a one-day delivery-time reduction when the carrier operates on weekends.
R13. User tier priority bonus reduces estimated delivery days.
R14. Express packages assigned to flight or truck receive a one-day delivery-time reduction, while economy packages assigned to shipment or freight rail incur a one-day delivery-time increase.
R15. Estimated delivery time is bounded to a minimum of one day.
R16. Base transport price formula: handling fee + (region distance x 3.0) + (weight kg x 0.08) + (shipping-range score x 2.5) + mode cost score + max(0, 6 - carrier reliability score) x 0.5.
R17. Estimated transport price has a minimum floor of 4.0 after rounding to two decimals.
R18. Route construction includes the retailer origin warehouse when available and each post office recorded in the package route.
R19. Route construction starts with the retailer, preserves the recorded post-office order without duplicates, and ends with the user.
R20. User tier and package priority influence the transport scoring model.
R21. Transport scoring formula: (estimated delivery days x combined speed weight) + estimated transport price + (mode cost score x package cost weight) - (carrier reliability score x 0.5).
R22. If no valid transport option exists, the computed outcome is infinite delivery time unless the package has already been received, in which case the outcome is 0.0.
R23. Selection reasoning may describe transport modes in terms of package priority, with faster modes presented as a better fit for express deliveries and slower modes presented as a better fit for economy deliveries.
R24. Shipping-range distance scores are fixed as follows: domestic = 0, regional = 2, intercontinental = 6.
R25. Region distance scores are fixed as follows: US North = 4, US South = 0, US East = 3, US West = 1, US Central = 2, Germany = 2, France = 2, Netherlands = 1, Spain = 0, Italy = 1, Poland = 3.
R26. Carrier base delay days are carrier-specific values that add directly to the estimated delivery days formula.
R27. Carrier reliability scores are carrier-specific values that reduce transport scoring by 0.5 per point and increase transport price through the term max(0, 6 - carrier reliability score) x 0.5.
R28. Mode cost scores are fixed as follows: flight = 5, shipment = 1, freight rail = 2, truck = 3.
R29. Mode transit days are fixed as follows: flight = 1, shipment = 7, freight rail = 4, truck = 3.
R30. Domestic deliveries are valid only when the retailer region and user region are the same, and the carrier region must also match that route region.
R31. Regional deliveries are valid only when the retailer region and user region belong to the same network type, meaning both US regions or both non-US regions, and the carrier region must belong to that same network type as the retailer.
R32. Selected carrier is chosen from the valid carrier and mode combinations only; each candidate is evaluated across every carrier and every mode that the carrier supports, and the option with the lowest transport score is selected.
R33. If a package is already delivered, selected carrier is empty because no new transport option is assigned. If no valid carrier-mode option exists for a package that is not yet received, selected carrier is also empty.
R34. Delivery priority values are fixed as follows: economy has speed weight 1 and cost weight 3, standard has speed weight 2 and cost weight 2, express has speed weight 3 and cost weight 1.
R35. User tier values are fixed as follows: standard has priority bonus 0 and speed weight 1, business has priority bonus 1 and speed weight 2, enterprise has priority bonus 2 and speed weight 3.
R36. Package category facts are fixed as follows: standard requires no special handling, fragile is flagged as fragile, perishable requires temperature control, hazardous requires hazardous-material certification.
R37. Mode maximum recommended package weights are fixed as follows: flight = 500.0 kg, shipment = 20000.0 kg, freight rail = 12000.0 kg, truck = 8000.0 kg.
R38. Selected carrier scoring combines package priority and user tier through combined speed weight = package priority speed weight + user tier speed weight, while package cost weight comes directly from the delivery priority.
R39. When multiple valid carrier-mode options have the same lowest score, the first one encountered during evaluation is selected.
R40. Estimated transport price then adds 8.0 for express deliveries or subtracts 1.5 for economy deliveries.
