# Introduction to Software Engineering/Introduction
## Introduction

This book is an introduction to the art of software engineering. It is intended as a textbook for an undergraduate level course.
Software engineering is about teams. The problems to solve are so complex or large, that a single developer cannot solve them anymore. Software engineering is also about communication. Teams do not consist only of developers, but also of testers, architects, system engineers, customer, project managers, etc. Software projects can be so large that we have to do careful planning. Implementation is no longer just writing code, but it is also following guidelines, writing documentation and also writing unit tests. But unit tests alone are not enough. The different pieces have to fit together. And we have to be able to spot problematic areas using metrics. They tell us if our code follows certain standards. Once we are finished coding, that does not mean that we are finished with the project: for large projects maintaining software can keep many people busy for a long time. Since there are so many factors influencing the success or failure of a project, we also need to learn a little about project management and its pitfalls, but especially what makes projects successful. And last but not least, a good software engineer, like any engineer, needs tools, and you need to know about them.

#### Developers Work in Teams

In your beginning semesters you were coding as individuals. The problems you were solving were small enough so one person could master them. In the real world this is different:- the problem sizes and time constraints are such that only teams can solve those problems.
For teams to work effectively they need a language to communicate (UML). Also teams do not consist only of developers, but also of testers, architects, system engineers and most importantly the customer. So we need to learn about what makes good teams, how to communicate with the customer, and how to document not only the source code, but everything related to the software project.

#### New Language

In previous courses we learned languages, such as Java or C++, and how to turn ideas into code. But these ideas are independent of the language. With Unified Modeling Language (UML) we will see a way to describe code independently of language, and more importantly, we learn to think in a level of abstraction which is higher by one level. UML can be an invaluable communication and documentation tool.
We will learn to see the big picture: patterns. This gives us yet one higher level of abstraction. Again this increases our vocabulary to communicate more effectively with our peers. Also, it is a fantastic way to learn from our seniors. This is essential for designing large software systems.

#### Measurement

Also just being able to write software, doesn’t mean that the software is any good. Hence, we will discover what makes good software, and how to measure software quality. On one hand we should be able to analyse existing source code through static analysis and measuring metrics, but also how do we guarantee that our code meets certain quality standards? Testing is also important in this context, it guarantees high quality products.

#### New Tools

Up to now, you may have come to know about an IDE, a compiler and a debugger. But there are many more tools at the disposal of a software engineer. There are tools that allow us to work in teams, to document our software, to assist and monitor the whole development effort. There are tools for software architects, tools for testing and profiling, automation and re-engineering.