13.1 The flow from Placing

Payment ──PlaceOrder──► Placing ──(PlaceOrder done)──► Placed ──Track──► Shipping ──(parcel ends)──► Delivered
                           │  ▲
               (run failed)│  │Retry
                           ▼  │
                          Failed

Two kinds of arrow are new. (PlaceOrder done) and (run failed) are outcomes: nobody sends them; the run that Placing started ends, and its ending moves the checkout. (parcel ends) is the same for a child machine. Every other arrow is an event a customer sends.

SDK Reference

Invoke a train from a state | Invoked runs | Spawn a child machine | Machine

Next: 13.2 What an invoked run is