25-2-25 - Lecture

Overview

• SE centres around coding

What Happens in SE

• Programming
• Co-ordinating a team, and plan and manage a project
• Understand user requirements
• Design the software (components/modules)
• Implement the components/modules
• Test the software
• Verify the software meets its goals
• Maintaining software

Software Lifecycle

1. Gathering requirements
2. Designing the system
3. Implementing the system
4. Testing and inspecting it
5. Maintaining (fixing and improving) it

Life Cycle Models

• Many different approaches

Common Categories

• Predictive life cycle: traditional, bulk of planning at the beginning, executing in a single pass - sequential
• Iterative life cycle: allows for feedback for unfinished work
• Incremental life cycle: provides finished deliverables that the customer may be able to use immediately
• Agile life cycle: both iterative and incremental

TODO: Finish this section from lecture notes

Activities

• Break up a project into a series of tasks → sub-tasks → bite-sized
• Helps identify how each task depends on each other
• Helps estimate duration for each task
• Helps the team understand what needs to be done
• Different tasks get assigned to different team members

Estimation

• Effort = time * number of people (in person-hours/months/etc)

Planning Poker

• A card game for estimating things (e.g. activity duration)
• Based on Wideband Delphi
• Each team member holds a set of cards: 0, 1/2, 1, 2, 3, 5, 8, 13, 20, 40, 100, ?, $\infty$
• Pick units, e.g. 3 weeks, 3 person hours, etc
• Play the game for each task in the WBS
  1. All team members play a card, face down, at the same time
  2. All team members turn over their card, at the same time
  3. Discuss why your estimates are all different

Critical Path

Gantt Charts