Chapter01.Introduction to Software Engineering

Chapter 1: Software and Software Engineering 13
What is Software Engineering?…
Cost, time and other constraints • The main economic constraints: —Finite resources —The benefit must outweigh the cost, then it is worth to do it —Others are competing to do the job cheaper and faster • Time constraint: —Delivered system within a limited budget before due date
Chapter 1: Software and Software Engineering
5
The Nature of Software ...
Untrained people can hack something together • Quality problems are hard to notice Software is easy to modify • People make changes without fully understanding it • Very difficult to make changes that are correct • Side effects of modifications: new bugs appear Software does not ‘wear out’ • It deteriorates by having its design changed: —erroneously, or —in ways that were not anticipated, thus making it complex

Mr. Brown: Zhonghua Computers. What can I do for you?
布朗先生：您好！中华计算机公司。我能为您做些什么？
Linda: Hello, Mr. Brown. It is Linda. Got a minute?
琳达：您好，布朗先生。我是琳达。您有时间吗？
Mr. Brown: I see your point. If we have to spend more time on developing the second version, we’ll have to adjust the schedule. People need to know that we have adjusted the project development plan as soon as possible. Do you want me to call the project manager?
Look and Learn Dialogue Reading Learn More New Words and Phrases
A software development project organization.
Lesson 14
Unit 5
Look and Learn Dialogue Reading Learn More New Words and Phrases
Mr. Brown: Yes.We planned to put the two versions in the same development process. Well, what kind of problem are you having now?
布朗先生：是的。我们计划在同一个开发过程中投入两个版本。那您现在遇到什么问题了？

• Software oriented courses Operating system Programming (C, C++, JAVA) Database Software engineering
What Is This Course About?
• To give directions for software development Development Skills Any other elements?
• Fritz Bauer
– [Software engineering is] the establishment and use of sound engineering principles in order to obtain economically software that is reliable and works efficiently on real machines
• Although the industry is moving toward component-based assembly, most software continues to be custom built. 虽然整个工业向着基于构件的构造模式发展，然而大多数软 件仍是根据实际的顾客需求定制的 • Software doesn’t wear out. 软件不会“磨损”
What is Software Engineering ?
What is this course about?
General Classification of Courses
• Hardware oriented courses Computer peripheral equipment Computer architecture Single chip

Chapter 1 An Introduction to Software Engineering＊What is software?-Computer programs and associated documentation and Data—Two fundamental types of software product：generic products and customized products＊What is software engineering?—Software engineering is an engineering discipline which is concerned with all aspects of software production*What is the difference between software engineering and computer science？—Computer science is concerned with theory and fundamentals;-software engineering is concerned with the practicalities of developing and delivering useful software*What is a software process?—A set of activities whose goal is the development or evolution of software-Generic activities in all software processes are：•Specification 、Development 、Validation 、EvolutionChapter 4 Software Process＊Software process-Software processes are the activities involved in producing and evolving a software system.-A structured set of activities required to develop a software system：specification;designand implementation;validation;evolution。