thought-works: Object oriented design for an online auction site

thought-works: Object oriented design for an online auction site
Typical set of operations on the online auction site from the user perspective are

• Users should register themselves and sign in to participate or start auctions in the online auction site. 
• A user can create a new item category to be auctioned in the site or else he can search ongoing auctions on the item and participate in one or more of these auctions simultaneously. 
• Upon participating in auction he/she can place the bids.
• He/she can come out of the auction at any time.
• If he wins the auction by placing the highest bid, he has to pay the bid price to the payment sub system
• If he is the owner of the auction which was complete with a winner, he should send the items to the delivery sub system.

Based on the above description the main components of the system would be

User -> can act as bidder/seller

Item -> Things which are sold and bought in the system

Auction -> Process in which seller wants to sell the item

Bid -> users quotes for the item being sold

Auctioneer -> one who oversees the process of start, stop and conducts the whole process

PaymentHandler -> component which accepts the payments from winning bidder and transfers the payment to the seller

Based on the above description this is the class diagram of the system:

Read full article from thought-works: Object oriented design for an online auction site