Are the relations of this domain model based uml class diagram correct and in which class should required methods be placed?

Question

I´m currently trying to visualize a class diagram for an ordering software, in which an Employee/User is able to create new orders, which have information about the Customer , the Products , the current status and the Employee who works on that specific Order .

My problem is that I don´t know which methods should be called in which class. Should the method createOrder() be in the class Order to creat itself or in the class User , because the User creates the Order in the software.

The methods I try to place inside the classes are:

• getAllOrders(), getMyOrders(), getAllCustomers(), getAllEmployees(),
• getOrderByID(orderID), getCustomerByID(customerID), createOrder(),
• createCustomer(), updateOrder(), updateCustomer(),

I would be very thankful for critiques and suggestion on my uml class diagram.

Image of my current domain model class- diagram .

Image of ER- diagram and a simplified state- diagram for a better understanding of my project (Both in one picture because I can only post two links.

Answer 1

I would advice you one more class - Basket. Every user has a basket, probably empty. An instance of the basket has a map of pairs Product - Number. Then it is obvious, what shall call createOrder() - the basket shall. At the moment, when the order is finished, the basket will lose it and will be free again.

As for GetAll... functions - make them static, or, in other words, belonging to the class, not instance. It is easy - each class can count or list its instances or specific instances.