1/25 - Software Engineering Process

Question 1

Software Process

Answer 1

1. Most projects follow recognized stages.

2. Process means HOW things are done, not what is done.

Question 2

Top Layer of Software Engineering

Answer 2

Tools: automate processes and methods

Question 3

Middle Layer of Software Engineering

Answer 3

Methods: the technical “how to”; design review, code review and testing

Question 4

Bottom Layer of Software Engineering

Answer 4

Process: framework of required tasks

Question 5

Waterfall Model

Answer 5

1. Gather requirements
2. Specification
3. Design
4. Implementation
5. Integration
6. Product
7. Testing after each phase

Question 6

Gather Requirements

Answer 6

1. Figure out the “what is this thing supposed to do?”
2. Raw list of features written down
3. Purpose: avoid building the wrong thing and gather information for planning
4. Talk to clients to figure out what they want

Question 7

Specification

Answer 7

A written description of what the system does for all inputs and in all possible states:

1. Covers all situations
2. More comprehensive than requirements

Question 8

Design

Answer 8

1. System architecture
2. Decompose the system into modules
3. Specify interfaces between modules
4. It’s more about HOW the system works than what it does

Question 9

Implementation

Answer 9

1. Code up the design
2. Plan how things will be done
   a. Specify the order
   b. Specify priorities
3. Test each module

Question 10

Integration

Answer 10

1. Put the pieces together

2. Test the entire system

Question 11

Product

Answer 11

1. Ship

2. Start maintenance

Question 12

Risks of Waterfall Model

Answer 12

1. Relies heavily on being able to accurately assess requirements at the start
2. Little feedback from the user until its late
3. Problems with specs found very late
4. Whole process can take a long time before a first version is seen

Question 13

Time

Answer 13

1. Taking a long time to build software is risky because
   a. the world changes quickly
   b. Others produce competitive software
   c. Tech becomes obsolete
   • Software depends on libraries, OS, compilers etc
2. Being fast simplifies programming
3. Being fast means you can refine your requirements quickly

Question 14

Accuracy of Models

Answer 14

1. Neither of these models are true to life

2. In reality you need feedback at all stages, waterfall model with feedback loops

Question 15

Iterative Models: Plan for Change

Answer 15

1. Use the same stage as the waterfall model
2. But plan to iterate the whole cycle several times
3. Gather requirements but don’t spend too much time; without something to show, cannot get full requirements.

Question 16

Pros of Iterative Models

Answer 16

1. Find problems sooner
2. Get early feedback
3. More quantifiable than waterfall model

Question 17

Cons of Iterative Model

Answer 17

Major mistakes in:

1. Requirements
2. Specs
3. Design