Why is booking lifecycle operations not modelled into a single class?

[Rohan_Palkar]

Looking at the class diagram, the booking lifecycle operations - createBooking(), updateBooking() and cancelBooking() - why aren’t they modelled into a single implementation class, more like a BookingService, instead of putting the operations into Customer class and Booking class separately ?

[Jimmy_P]

The modeling in general is really poorly done in my opinion.