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软件工程大题总结
一、三个重要的生命周期模型及各自的优缺点
1.瀑布模型生命周期模型（Waterfall life-cycle model）
Advantage: Disciplined approach
Document driven
Disadvantage: Delivered product may not meet client’s needs
2.快速原型生命周期模型（Rapid prototyping life-cycal model）肠仔包的做法
Advantage: Ensure that the delivered product meets the client’s needs
Disadvantage: Not yet proven beyond all doubt
3.螺旋模型生命周期模型（Spiral life-cycle model）
Advantage: Risk driven
Disadvantage: Can be ud for only large-scale,in-hou products
treat的名词
Developers have to be competent in risk analysis and risk resolution
二、用例图和类图
世说新语任诞
例1. ATM机用例图及类图
唐一白Consider an automated teller machine(ATM).The ur puts a card into a slot and enters a four-
digit personal identification number(PIN).If the PIN is incorrect,the card is ejected.Otherwi,
the ur may perform the following operations on up to four different bank accounts:
(i)Deposit any amount.A receipt is printed showing the date,amount deposited,and account number.
(ii)Withdraw up to $200 in units of $20(the account may not be overdrawn).In addition to the money,the ur is given a receipt showing the date,amount withdrawn,account numb
er,and account balance(余额) after the withdrawal.
(iii)Determine the account balance。This is displayed on the screen.
(iv)Tranfer funds between two accounts.Again,the account from which the funds are transferred must not be overdrawn.The ur is given a receipt showing the date,amount transferred,and the two account numbers.
(v)Quit.The card is ejected.
Explain how you would ensure that as many code artifacts as possible the product
can be reud in future products.
(1)Draw the U Ca Diagram马致远秋思
(2)Draw the Class Diagram(three refinements)
引人注目
1)The firs refinements,we find three class which are ur,ATM and account.
2)The cond refinements,we find that ur doesn’t change while the system is operating.
3)In the third refinement,we find that ATM also doesn’t change while the system is operating.So catalog is information that relates to Accounts. This leaves Account as the sole candidate class.
例2.黄鼠狼 电梯用例图及类图
A product is to be installed to control n elevators in a building with m floors. The problem concern the logic required to move elevators between floors according to the following constrains:
1) Each elevator has a t of m buttons, one for each floor. The illuminate when presd and cau the elevator to visit the corresponding floor. The illumination is canceled when the corresponding floor is visited by the elevator.
2) Each floor, except the first floor and the top floor, has two buttons, one to request an up-elevator and one to request a down-elevator. The buttons illuminate when presd. The illumination is canceled when an elevator visits the floor and then moves in the desired direction.
