Determine candidate classes Some questions can help us to group the candidate classes and objects What needs to be"in some way What items have multiple attributes? When do you have more than one object in a class What is based on the requirement themselves, not derived from your understanding of the requirements What attributes and operations are always applicable to a class or object?
Determine candidate classes • Some questions can help us to group the candidate classes and objects. – What needs to be “processed” in some way? – What items have multiple attributes? – When do you have more than one object in a class? – What is based on the requirement themselves, not derived from your understanding of the requirements? – What attributes and operations are always applicable to a class or object?
Related Requirement Statements a customer has the option to be billed automatically at the time of purchase(of fuel, maintenance, or parking)or to be sent a monthly paper bill. In either case, customers can pay using cash, credit card or personal check. Royal Service Station fuel is sold according price per gallon, depending on whether the fuel is diesel, regular, or premium. Service is priced according to the cost of parts and labor Parking is sold according to daily, weekly, and monthly rates. The prices for fuel, maintenance services, parts, and parking may vary only Manny, the station manager, can enter or change prices. At his discretion, Manny may designate a discount on purchase for a particular customer; this discount may vary from one customer to another. A 5% local sales tax apples to all purchase
Related Requirement Statements A customer has the option to be billed automatically at the time of purchase(of fuel, maintenance, or parking) or to be sent a monthly paper bill. In either case, customers can pay using cash, credit card, or personal check. Royal Service Station fuel is sold according to price per gallon, depending on whether the fuel is diesel, regular, or premium. Service is priced according to the cost of parts and labor. Parking is sold according to daily, weekly, and monthly rates. The prices for fuel, maintenance services, parts, and parking may vary; only Manny, the station manager, can enter or change prices. At his discretion, Manny may designate a discount on purchase for a particular customer; this discount may vary from one customer to another. A 5% local sales tax apples to all purchase