software design

Software design

Problem solving and planning a software solution.

1. Low level company and algorithm design

2. High level architectural design

Software design methodologies

Strategies employed to create a software design

Aspects of software design

RODAT:

1. Requirement gathering

2. Object oriented design

3. Design patterns

4. Architectural patterns

5. Testing

Problem domain

1. Actors: agents external to the system interacting with it

2. Objects: agents working inside the system that make it function

3. User stories: scenarios for using the system

Software development methodologies

1. Waterfall

2. Iterative and incremental

3. Agile

Waterfall

1. Unidirectional

2. One phase after the other

Phases of Waterfall

1. Requirements

2. Design

3. Implementation

4. Verification

5. Maintenance

Role of software engineer

Understand how the system-to-be needs to interact with the user or environment so that customer requirements are met and design the software

Programmers task

Implement the software-to-be designed by software engineer

Waterfall pros

1. Simple to come up with

2. Easy to manage

Waterfall cons

1. Only have working product at the end

2. Hard to revise

3. Does not incorporate feedback

4. Not suitable for larger systems

Iterative and incremental

Create minimum viable product and incrementally add to it

1. Increments defined by amount of work to be done

2. Repeat till done

Iterative and incremental pros

1. MVP out sooner

2. Incorporates feedback

3. Can work in order of priority

4. Client can give feedback after each iteration

Iterative and incremental cons

1. Harder to manage

2. Initial planning must be efficient as every increment must work with future increments

3. Defining increments can be difficult

Agile

Builds on iterative and incremental

1. Increments defined by timed intervals

2. Not so much planning focus on immediate requirements

3. Focus on collaboration

Agile pros

1. Early and frequent release

2. Accommodate changing requirements

3. Constant feedback

4. Simple

Agile cons

1. Can be difficult to constantly meet with client

2. Requires more discipline to meet time goals

3. Time estimation needs to be good

Scrum

1. Development team: developers, analysts, domain experts

2. Product owner

3. Scrum master

Development team role

1. Autonomy on how to develop increment

2. Collaborative

Product owner role

1. Responsible for vision

2. Reprioritises backlog constantly

3. Final arbiter on requirements

Scrum master role

1. Part of dev team

2. Facilitate the scrum process

3. Ensure team works together smoothly

4. Leader not manager

Scrum ceremonies

1. Sprint planning

2. Daily scrum

3. Sprint review

4. Sprint retrospective

5. Backlog refinement

Sprint planning

1. Product backlog

2. Dev team and product owner work together to pull backlog items into the sprint

3. Break each backlog item into task

4. Estimate how many backlog items to do in time window

5. Prioritize certain backlog items over others

Daily scrum

1. 15 min daily

2. Create plan for day

3. Discuss goals for today

4. Commit to you and your team

Sprint review

1. Meet with product owner

2. Live demo of current version of product

3. Code complete

4. Deployed to appropriate env

5. Adequately tested feedback

6. Product owner determines which backlog items are done

Sprint retrospective

1. Reflect on how the last sprint went

2. How team can improve

3. Needs to be transparent and safe space for devs

4. Avoid blaming

Backlog refinement

1. Take product backlog and refine it

2. Break down large items into smaller ones

3. Adjust estimates based on progress

4. Reassess priorities

5. Prune unnecessary items