Reservations / Order Creation

Core booking system handling Order creation, lifecycle management, and passenger data. Built on an Order-Centric architecture where the Order is the Single Source of Truth.

Scope

Order-Centric Model (Primary)

The Order replaces the fragmented legacy approach. Every booking is an e-commerce transaction:

┌─────────────────────────────────────────────────────────────────┐
│                      ORDER (UUID)                               │
│                                                                 │
│  ┌──────────┐  ┌──────────┐  ┌──────────┐  ┌──────────┐       │
│  │ Flight   │  │   Seat   │  │ Baggage  │  │   Meal   │       │
│  │   SKU    │  │   SKU    │  │   SKU    │  │   SKU    │       │
│  └──────────┘  └──────────┘  └──────────┘  └──────────┘       │
│                                                                 │
│  State: OFFERED → PAID → FULFILLED                             │
│                                                                 │
└─────────────────────────────────────────────────────────────────┘

Key Principles:

• Universal Order ID (UUID v7): Primary identifier for all operations
• Seat as SKU: Every product is a line item in the order
• Single Source of Truth: All systems query the Order
• State-Driven: Check-in prohibited unless Order.Status == PAID

Order State Machine

OFFERED ──────────────► PAID ──────────────► FULFILLED
    │                     │                      │
    │ (10 min timeout)    │ (refund/cancel)      │ (post-flight)
    ▼                     ▼                      ▼
 EXPIRED              CANCELLED              COMPLETED

Booking Flows

• Search → Select → Passenger Details → Ancillaries → Payment → Confirmation
• Multi-city and complex itineraries
• Round-trip and one-way bookings
• Group bookings (10+ passengers)
• Corporate/TMC bookings

Legacy PNR Compatibility

• Record locator (6-char) retained as secondary identifier
• Legacy systems can query by PNR, resolved to Order ID
• PNR generated for backward compatibility only

Research Topics

• Order state machine edge cases
• Booking validation rules
• SSR codes and handling (WCHR, VGML, etc.)
• Order expiration and cleanup
• Split/merge order operations
• Name change policies and implementation
• Multi-currency order handling

Architecture Considerations

Saga Pattern for Order Creation

1. HoldInventory (with compensation: ReleaseInventory)
      ↓ Order.Status = OFFERED
2. CreateOrder (with compensation: ExpireOrder)
      ↓
3. ProcessPayment (with compensation: RefundPayment)
      ↓ Order.Status = PAID
4. ConfirmOrder
      ↓
5. SendNotification

Order Data Model

Order
├── OrderID (UUID v7) ────────────── Primary identifier
├── RecordLocator (6-char) ───────── Legacy PNR reference
├── Status ───────────────────────── OFFERED | PAID | FULFILLED | etc.
├── ExpiresAt ────────────────────── For OFFERED state (10 min)
│
├── Customer
│   ├── CustomerID, Email, Phone
│   └── LoyaltyID (optional)
│
├── Passengers[]
│   ├── PassengerID, Name, Type (ADT/CHD/INF)
│   ├── Documents[]
│   └── SSRs[]
│
├── Items[] ──────────────────────── Line items (SKUs)
│   ├── SKU, Type (FLIGHT/SEAT/BAGGAGE/SERVICE)
│   ├── PassengerRef, SegmentRef
│   ├── Pricing (Base + Taxes + Total)
│   └── Status (OFFERED/CONFIRMED/DELIVERED)
│
├── Segments[]
│   ├── FlightNumber, Date, Route
│   ├── PriceTier (P1-P5)
│   └── CabinClass
│
├── Payments[]
│   ├── TokenRef (from vault)
│   ├── Amount, Currency
│   └── Status
│
└── History[] ────────────────────── Audit trail

Idempotency Requirements

• Order creation with client-generated request ID
• Payment processing must be idempotent
• Retry-safe inventory holds
• Optimistic locking for concurrent modifications

Integration Points

API Design

Key Endpoints

• POST /orders - Create order (returns OFFERED state)
• GET /orders/{id} - Retrieve order by UUID
• GET /orders?pnr={locator} - Retrieve by legacy PNR
• PUT /orders/{id} - Modify order
• POST /orders/{id}/pay - Process payment (transitions to PAID)
• DELETE /orders/{id} - Cancel order
• POST /orders/{id}/items - Add line item (SKU)

NDC Message Mapping

Critical Business Rules

Revenue Protection

┌─────────────────────────────────────────────────────────────────┐
│                                                                 │
│   CRITICAL: Check-in PROHIBITED unless Order.Status == PAID     │
│                                                                 │
│   DCS queries OMS in real-time. No passenger boards without     │
│   confirmed payment. This eliminates revenue leakage.           │
│                                                                 │
└─────────────────────────────────────────────────────────────────┘

10-Minute Hold Window

• OFFERED orders expire after 10 minutes
• Inventory automatically released on expiration
• Prevents phantom inventory blocking