1) identify the entity or entities that represent a supertype and the entities that are subtypes

2) specify which attributes the subtypes inherit from the supertype(s)

3)specify which attributes are unique to each subtype

Conceptual Data Model for e-Commerce Game Store Barry Williams 21st. May 2001 Product_Types product type code product_type_description Customer Orders order id date_of_order other_order_details Customer customer ID customer_Code customer_Name customer_Address customer_Other Details Products product id product_description product_name product_price Customer Purchases Games game_name memory_required number_of_players other_game_details Consoles drive_type size other_console_details purchase id date_of_purchase other_purchase_details Accessories accessory_name accessory_description other_accessory_details