Question

  

A retail store wants to build an online system for their customer to place orders online and for pickup later from the store. Customers join the system by registering online (username (email), password, address, phone no) and including a credit card for use in online ordering; at that time they use login credentials (uername and password) to enter the online system. Customers who have joined the system can use the online system to search for products, select products, specify amounts or weights for products where necessary, and place orders for those products, specifying a pick-up time. (The system enforces a 24-hour minimum pick-up time). When an order has been placed, an email confirming its receipt and listing order details is sent to the customer. (Customers have the opportunity to edit their order for a certain period of time). When an order is received by the system it is forwarded to order processors, who collect and package up the ordered items, and sends an email confirming the completion of the order to the customer. The customer go to the store in the chosen pick-up time, call a number to inform his arrival, and waiting to the designated area. Cashier charges the customers' credit card appropriately and deliver the order. Customers can use the on-line system to check past orders, to inquire into order statuses, and take a short survey after every order. The system logs information on all orders, containing details on what was ordered, charges, and order status. One alternative scenario is worth noting. When customers order products, they are allowed to order only products (or amounts of products) that are currently present in inventory. When order processors are processing orders, however, inventory may have changed, and certain products (or requested amounts of those products) may no longer be available. Such products are omitted from the orders, or supplied to the extent possible. Such cases are noted and inform (by email and a phone call) to the customer. The customer is not charged for such items. Another alternative scenario is if customers do not show up in the chosen pick-up time, they will be charged based on their delay.

Prepare a design class diagram.

Answer 1

Based on the given requirements, I have designed an UML class diagram

Classes identified are

• Store
• Product
• Customer
• Order
• Order_History

Classes and their relationships based on the given business rules

• Store has many products as one to many relationship (1,*)
• Customer place many orders online as one to many relationship (1,*)
• One order may have many products or one product as one to many or one to one relationship (1,1) or (1,*)
• Order will maintain order details so that customers and store can search orders at any time , get information whatever needed as many to many relationship (*,*)
• Customer will track order history or past orders and give feedback, search orders and track order status
• Attributes which are bold and underlined will be primary keys, while foreign keys are referred in italics for Class - database table mapping as part of ORM ( Object Relational Mapping)
• User_Email has been used as a primary key which is a natural candidate key .

UML Class Diagram

Online Retail Store Order Customer -UserEmail : string -password :string -address : string -phone: string -CreditCard_Number: int -Expiry_date: date -CardType : string +Signup +Logino +Deactivate Account -Order_Number: int -Order_date date -UserEmail : string - Product_ID: string -Weight : decimal (9,2) -Pickup_time: int -Delivery_Date : date -Paid_status: string -Delay_Pickup_charges : Decimal(9,2) -Order_status: string +OrderEntry +Updateorder) +CancelOrdero +TrackStatus +Search Product -Product_ID: string -Product_Name : string Description : string -Quantity_In_Hand : int -Unit_Price :Decimal -Store_Number : string +Addo +Modify +Delete() +Search() Store Order_History -Order_Number: int -Customer_Feedback string -UserEmail : string +SearchOrders) +AddFeebacko +TrackStatus -Store_Number: string -Store_Name: string -Address:string -Phone: string +Add( +Modify +Delete