Software engineering topics

Analysis of software engineering problems

1. A stock exchange provides securities trading services for convenience , To develop a securities trading platform , The main functions of the platform are as follows ：（1） Accounts . According to the account opening information submitted by the customer service assistant , Open an account , And put the customer information into the customer record , Account information （ Balance, etc ） Into the account record ;（2） deposit . Customers can deposit money into their accounts , Modify account balance according to deposit amount ;（3） Withdraw money . Customers can withdraw money from their accounts , Modify the account balance according to the withdrawal amount ;（4） Securities trading . Both clients and brokers can trade securities （ Customers go online , Agent on the phone ）, Put the transaction information into the transaction record ;（5） Check the deal . The platform reads the transaction information from the transaction record , Return the transaction details to the customer . Now we use the structural method to analyze and design the securities trading platform , Obtain the following figure 1-1 The context data flow graph and graph 1-2 Shown 0 Layer data flow graph .

（1）E1： Customer service assistant ,E2： Customer ,E3： agent ,D1： Customer records , D2： Account records ,D3： Transaction records .

（2） Data stream name ： The account balance , The starting point ： deposit , End ：D2.
Data stream name ： The account balance , The starting point ： Withdraw money , End ：D2.
Data stream name ： Transaction information / Transaction records , The starting point ： Securities trading , End ：D3.
（3） name ： Transaction details
describe ： Customer specific transaction information
source ： Check the deal
Whereabouts ： Customer
form ： Stock code + Name of the securities + operation + Number of deals + The closing price + amount of money + Contract No + Profit and loss amount

2. A library lending management database requires the following services ： １） You can query the varieties of existing books in the library at any time 、 Quantity and storage location . All kinds of books can be uniquely identified by the book number . ２） You can check the borrowing and returning of books at any time , Including the borrower's unit 、 full name 、 Library card number 、 Borrowing date and return date . We have an agreement ： Anyone can borrow a variety of books , Any kind of book can be borrowed by more than one person , The library card number is unique . ３） When required , The press's telegram number can be saved in the database 、 Telephone 、 Add relevant books to the corresponding publishing house under the information of postal code and address . We have an agreement , A publishing house can publish many books , The same book is published by only one publisher , The publisher name is unique . According to the above conditions and assumptions , Try the following design ： （１） Construct a that meets the requirements Ｅ-Ｒ chart . （２） Transform to an equivalent relational schema structure .

3： The data flow chart of a train ticketing system is as follows

5. The calculation scheme of class pay of a school is as follows ：(l) The basic course fee is for each class 10 element ;(2) If the class size exceeds 40 people , Increase in class pay ： Basic class pay ×0.1;(3) If the class size exceeds 60 people , Increase in class pay ： Basic class pay ×0.2;(4) If the teacher is an associate professor , Increase in class pay ： Basic class pay ×0.1;(5) If the teacher is a professor , Increase in class pay ： Basic class pay ×0.2;(6) lecturer , No increase in class pay ;(7) Assistant , The class pay is reduced ： Basic class pay ×0.1. Please use the decision table and the decision tree to represent the class pay calculation scheme .

6. The following code is used to judge whether the entered year is a leap year , Design test cases for decision coverage and condition coverage .

if (year<0)
return -1;
  if ((year%4==0&&year%100!=0)||(year%400==0))
    return 1;
  else
   return 0;

Determine the test cases covered ：
The test case 1：year=-2, Satisfy T1(T1 Indicates that the number is 1 The decision node of takes the true value )
The test case 2：year=2008, Satisfy F1T2( Decision nodes 1 Take false value , Decision nodes 2 True value )
The test case 3：year=2013, Satisfy F1F2( Decision nodes 1 Take false value , Decision nodes 2 Take false value )
Test cases covered by conditions ：
The test case 1：year=-2, Satisfy T1
The test case 2：year=2008, Satisfy F1T2T3
The test case 3：year=2013, Satisfy F1F2F4
The test case 4：year=2000, Satisfy F1T2F3T4

7. User login box test , We should consider from two aspects ：（1） account number ： The length is 6_{10 Four digit characters ;（2） password ： The length is 6}16 Digit number 、 Symbol 、 English characters . Please use the equivalent class division method to design test cases for the user login box test .

The primary selection method of the graduate enrollment system of a university is as follows ： Total score 300（ contain ） Enter the candidate student pool , Otherwise, reverse gear ; The math score is not lower than 70 branch , Then enter the three-level alternative Library , Otherwise, enter the level IV alternative Library ; Based on the three-level alternative Library , If the professional course score is higher than 100 branch , Then enter the primary alternative Library , Otherwise, enter the secondary alternative Library , Answer the following questions ：（1） Write structured language .（2） Draw the corresponding decision table .（3） Draw the corresponding decision tree .

1. ( Other ) Suppose you are appointed project leader of a software company , Your job is to manage the development of new versions of the company's widely used word processing software . Because of the fierce competition in the market , The company has set a strict deadline for completion and has announced . You are the project leader , What kind of software process model do you intend to adopt ? Why? ？ Please give reasons .

right key ：

An important requirement for this project is , Complete product development in strict accordance with the published date , therefore , When selecting a lifecycle model, you should consider which model will help accelerate the progress of product development . When using incremental model to develop software, the development work can be completed in parallel , Therefore, it can speed up the development progress .

This project is to develop a new version of the company's widely used word processing software , From the above facts, we can at least draw a conclusion that 3 Make a conclusion ： First of all , The old version is equivalent to a prototype , By collecting the user's response to the old version , It is easier to determine the requirements for the new version , There is no need to build a prototype system to analyze the needs of users ; second , The company's software engineers are familiar with word processing software , Have rich experience in developing word processing software , Have the technical level required by the incremental model to develop the new version of word processing software ; Third , The software is loved by the vast number of users , In the future, it is likely to develop an updated version , Therefore, the software architecture should be designed to be open , It is conducive to future improvement and expansion .

in summary , It is appropriate to use incremental model to complete the project .