Software Engineering Overview

1. Software Engineering Overview 23 January

2. Software Engineering Overview • What is engineering? • Why is software engineering different than other engineering disciplines? • Is software engineering different than • computer science? • programming? • How similar or different are software engineering projects?

3. Engineering • Turning ideas into reality • Creating something useful from other things using science and math

4. Software Engineering vs. Other Engineering Disciplines • Maturity • Roman aqueducts 2000 years ago • Software engineering 50 years ago • Startup costs • Barriers to entry • Rate of change

5. What’s in a Name? • Software engineer • Computer scientist • Programmer • Coder • Developer • Designer • Architect

6. Different Types of Projects • Consider 4 different types of systems • COMP 523 projects • Productivity suites • Commercial web sites • Airplane systems • Pacemakers • How do they differ in criticality? • What does that mean for the development process?

7. Expectations of Software Engineering(Watts Humphrey) • Predetermine quantitative quality goals • Accumulate data for use in later projects • Keep all work visible • Design, program and test only against requirements • Measure and achieve quality goals

8. Keeping Work Visible: Documentation • What will be implemented • Customer: contract, requirements, “glossy” • User: manuals • How it will be implemented • Project plan • The code • The test plan • What people will do • How you will manage code and documents

9. Documentation Principles • Need to reflect changes • Version control • Need to keep all documents synchronized • Single owner • Only say it once

10. Quality Management Principles • Customer focus • Leadership • Involvement of people • Process approach • System approach to management • Continual improvement • Factual approach to decision making • Mutually beneficial supplier relationships http://www.iso.ch/iso/en/iso9000-14000/iso9000/qmp.html

11. Customer Focus • Organizations depend on customers • Understand needs, requirements, expectations • Increases market share • Implies • Market research • Customer understanding throughout the organization • Measuring satisfaction

12. Involvement of People • Essence of the organization • “Buy in” • Two way street • Treating people with respect • They will take on ownership of responsibility • Encourage a collaborative environment

13. Software Engineering Fundamental Steps • Requirements • Design • Implementation • Integration • Test (elaborated versions to be covered later)

14. Processes • Differ by how often you do the steps • Points on the spectrum • Differences in overhead • Three fundamental models • Waterfall • Spiral • Iterative

15. Waterfall • Do it once • Traditional model • Used for large next version releases, especially when tightly coupled changes • Pros • Simple documentation management • Clean design phase • Cons • Least flexibility • No early feedback

16. Spiral • Few iterations • Each iteration adds new requirements • Used often for projects with less well defined requirements • Pros • Adaptation to changes based on risks • Good customer interaction • Early version • Limited iterations provide phase structure • Cons • Document maintenance

17. Iterative • Many iterations • Each iteration is on a fixed cycle • Typically weekly • Used for projects with lots of small independent, but well understood, changes • Pros • Fast feedback on problems • Very adaptable to any changes • Lots of versions to work with • Cons • Document maintenance • Code maintenance • Requires good automation