Software Engineering Process

Question 1

Fundamental Process Activities

Answer 1

Software specification:
- definition of the software to be produced and contraints
Software development:
- Design, implementation and verification
Software validation:
- ensure that software behaves as required by customer
Software evolution:
- adaption and modification to cope with changing requirements

Question 2

Software Engineering Process Model - Waterfall Model

Answer 2

1. Requirements definition:
   - requirements are defined in detail and serve as system specification
2. System and software design:
   - definition of overall architecture
   - identification of the fundamental abstractions
3. Implementation and unit testing:
   - software design realized as set of program units
   - testing verifies that specification is met
4. Integration and system testing:
   - units are integrated and tested as complete system
5. Operation and maintenance

Question 3

Software Engineering Process Model - Waterfall Model

Criticism

Answer 3

• early prototyping impossible
• change of requirements, design, etc. difficult
• testing start only in later stage
• different phases executed by different teams

Question 4

Software Engineering Process Model - Agile Development

Key Points and Goal

Answer 4

Goal: develop software quickly in presence of rapidly changing requirements

Key Points:

• changing requirements during development highly problematic
• render development cycles small & fast (agile)
• customer and developer work closely together

Question 5

Software Engineering Process Model - Extreme Programming (XP)

Answer 5

set of simple, interdependent elemts/ practices:

• customer (Element)
• User Story (Practice)
• Acceptance Test (Element) (detailes of the user soties)
• Short Development cycles (Practice)
• the planning game (Practice) (Business decide how important a feature is, developers decide €)
• simple design (practice)
• Test-Driven Development (Element) (Implementation starts with writing tests)
• Continuous Integration (Practice) (after each commit system is build and tested)
• Refactoring (Element) (design techniques)
• Pair Programming (Practice)
• Collective ownership
• coding standards
• Sustainable pace
• open workspace

Question 6

Software Engineering Process Model - Extreme Programming (XP)

User Storys

Answer 6

Text stories with rated difficulty that describe requirements identified with the customer

INVEST

• Independent
• Negotiable
• Valuable (deliver value to the end user)
• Estimable (possible to estimate size)
• Size appropriately or Small (otherwise split)
• Testable

Question 7

Software Engineering Process Model - Extreme Programming (XP)

Planning

Answer 7

Initial Exploration
- identify all significant user stories and rank them
Release Planning
- set first release date
- customer orders user stories and as velocity gains accuracy adjust release plan
Iteration Planning
- customer picks stories for iteration n
- iteration ends on specific date independent from finished stories
- velocity of iteration: succesfull finished stproes / time
- plannend velocity for iteration n + 1 = velocity of iteration n