Software Development Lifecycle

Systematic process to develop high quality software
meet requirements
defined phases for deliverables
planning, design, and development
minimize development risk and costs

6 Phases

Planning
Design
Development
Testing
Deployment
Maintenance

Waterfall model

Waterfall assumed linear progression of phases

V Shape Model

assumes linear progression

Verification
- Plan
- System Design
- Architecture Design
- Module Design
Coding
Validation
- Unit Testing
- Integration Testing
- System Testing
- Acceptance Testing

Agile

Iterative Sprint wise development MVP is released after that

Planning

Gather Analyze Document Prioritize

Points to consider

Users
Purpose
Inputs/Outputs
Compliance - legal and regulatory
Risk Identification
Quality Assurance
Allocation of human and financial resources
Project Scheduling Document into SRS (Software Requirement Specification)

Design

Architecture and prototyping

Development

Testing

Unit
Integration
System
Acceptance

Deployment

UAT-User acceptance testing

Maintenance

Common Software Engineering Processes

Requirement Gathering
Design
Coding for quality
Testing
Releases
Documenting

Requirements Gathering

Functional
External/User Interface
System Features
Non functional

Coding for quality

Maintainability
Readability
Testability
Security

Releases

Alpha
Beta
GA - General Availability

Documenting

System Documentation - Generally for sdes
User Documentation

Requirements

SRS
URS
SysRS

SRS

1st Part
- Purpose (Who has access, how it should be used)
- Scope (Software benefits, Goals, Objectives)
2nd Part
- Constraints (how the software must operate under given conditions)
- Assumptions (required OS, hardware)
- Dependencies (e.g. on other services or products or external apis)
Requirements
- Functional - functions of software
- External - users & interactions with other hardware or software
- System features - functions of the system
- Non functional - performance, safety, security, quality

functional - benchmarks, service level for performance
purpose and scope
constraints, assumptions and scope
requirements

URS

Describe business needs and end user expectations
User Stories
- Who is the user
- What is the function that needs to be performed
- Why does the user want this functionality
Confirmed during UAT
Often Combined into the SRS

SysRS

Outline Requirements of the system
Broader than SRS
Contains:
- System Capabilities
- Interfaces and user characteristics
- Policy
- Regulations
- Personnel
- Performance
- Security
- System acceptance criteria
- Hardware Expectations

Software Versioning

4 numbers usually

major version
minor version
patches
builds

Software Testing

Functional Testing
- Black box testing (I/O -> O/P)
- Usability
- Accessibility
Non Functional Testing
- Performance
- Security
- Scalability
- Availability
Regression Testing
- confirms new changes do not affect existing functionality Testing levels
Unit
Integration
System
Acceptance

Software Development