State diagram makerfrom plain language, free.

stateDiagram-v2
  [*] --> Placed
  Placed --> AwaitingPayment : checkout
  AwaitingPayment --> Paid : payment succeeded
  AwaitingPayment --> Cancelled : payment failed
  Placed --> Cancelled : customer cancels

  state Fulfilment {
    direction LR
    [*] --> Picking
    Picking --> Packing : all items found
    Picking --> Backordered : out of stock
    Backordered --> Picking : stock arrives
    Packing --> ReadyToShip : label printed
  }

  Paid --> Fulfilment
  Fulfilment --> Shipped : handed to courier
  Shipped --> InTransit : scanned at depot
  InTransit --> Delivered : signed for
  InTransit --> DeliveryFailed : nobody home
  DeliveryFailed --> InTransit : retry next day
  DeliveryFailed --> Returned : third failed attempt

  Delivered --> RefundRequested : customer asks
  Returned --> Refunded
  RefundRequested --> Refunded : item received back
  RefundRequested --> Delivered : request declined
  Paid --> Refunded : cancelled before shipping

  Delivered --> [*]
  Refunded --> [*]
  Cancelled --> [*]