1. Introduction To software engineering
CS 360
Lecture 1

2. Introduction to Software engineering
If you don’t understand it, you can’t program it. If you can’t measure it, you can’t improve it.

3. Software engineering Definition:
SWE covers all aspects of building software systems, along with management issues such as directing teams, scheduling, and budgeting.

4. Introduction to Software engineering
More and more systems are software controlled

5. Introduction to Software engineering
That’s good news for us!

6. Software engineering Software Jobs:
1990: 778,000
1995: 1,083,000
2010: 2,095,000
2014: 2,501,000
2016: 3,360,000
2018: 4,200,000
Software jobs growing faster than any other jobs.
2014: 2.2% of all U.S. employment
Average salary for new employees in the software industry: ~$70k
Average salary per person in the U.S.: ~$40k

7. Software Life-Cycle costs
Software costs more to maintain than it does to develop.

8. Software Engineering Body of Knowledge
Computing Fundamentals
Algorithms and Data Structures
Computer Architecture
Operating Systems
Mathematical Foundations
Software Product Engineering
Requirements Engineering
Software Design
Software Coding
Software Testing
Software Operations & Maintenance
Software Management
Project Process Management
Risk Management
Quality Management
Configuration Management
Dev. Process Management
Acquisition Management
Software Domains
Artificial Intelligence
Database Systems
Human-Computer Interaction
Numerical & Symbolic Computing
Computer Simulations
Real-Time Systems

9. Software Engineering vs. “other” engineering
How is software engineering different than other types of engineering?
Exists entirely on and bounded by the rules of hardware.
Software logic is not bounded by physical laws.
Capacity to incorporate massive complexity.
Does not have problems due to product aging.

10. Software Engineering Why is software engineering difficult?
You need to understand the problem domain
You need to understand the software domain
Software is formal
Real world is informal

11. Computer Science Computer Scientist:
Proves theorems about algorithms, designs languages, defines knowledge representation schemes, etc.

12. Software Engineer Software Engineer:
Creates the design for the real-world problem

13. Software Developer Software Developer:
Generates the code for the real-world problem

14. Software Engineering
Software engineering is concerned with cost- effective software development.
First determine the needs of the client.
These needs/requirements may change over time.
Then design, construct, test, add features to the software system, and repeat.
Each member of the CS 360 project teams will be providing roles computer scientist, software engineer, and software developer.

15. Software engineering diversity
The software engineering methods and tools used depend on:
The type of application being developed
The requirements of the client
The background of the development team
In this class, the teams will be diverse, and the client’s requests may change over time.

16. Software Development Process Models

17. Software Process: Quality control steps in all software development
Feasibility study and planning
Gathering/validating the requirements
System/program design and software modeling
Implementation
Testing
Bug fixing, feature enhancements, and maintenance
These steps may be
repeated many times
during the development
cycle.

18. Software Process Step: Feasibility
The feasibility study

19. Software Process Step: Requirements
Requirements define the function of the system from the client’s viewpoint.
Requirements establish:
System functionality and scope
Constraints
Dependencies
Goals
Development process

20. Software Process Step: Requirements
The requirements step is divided into tasks:
Requirements analysis
Meetings, documentation, process specifications, use cases, etc.
Requirements definition
Description of the services that the system should provide.
Requirements specification
Functional requirements
Inputs, behavior, outputs
Non-functional requirements
Criteria used to judge the operation of the system
Ex: Security, performance, reusability, stability, usability, etc.

21. Software Requirements Example
I want to create a website that hosts many funny pictures of dogs.
1. List examples of functional requirements (Defined behavior/technical details)
2. List examples of non-functional requirements (System judgement criteria/constraints)

22. Software Process Step: System/Program Design and modeling
Design describes the system from the software developer’s viewpoint.
System design:
System architecture
hardware and software that matches requirements.
Program design:
Software functions that can be converted into executable programs.
Software design patterns
Models are used to represent requirements, system architecture, and programming design.
Unified Modeling Language (UML)

23. Software Process Step: Implementation
Implementation (coding):
The software design is realized as a set of programs.
Software
May be written by the development team
Modified from existing components

24. Software Process Step: Testing
Testing stages:
Unit testing
Integration testing
System testing
Acceptance testing

25. Software engineering Processes
Every software project will include the previous basic processes, in some shape or form, but:
The steps may be formal or informal
The steps may be carried out in different order
Your job is to implement, in as much detail as possible, the processes described to develop a good software product.
Organization/planning
Gathering/validating requirements
Developing/verifying component/system designs
Implementing/source code development
Testing
Repeat…
All details of the software engineering process should be documented in the milestone reports.