Most dev teams know this feeling. The plan made sense at the start. Three sprints in, the client wants something else. Two weeks of work needs to change.
That is not a client problem. That is a planning problem.
The agile software development model was built for this. It accepts change. Here is what you need to know.
Agile Development Model in Software Engineering
The agile development model in software engineering builds software in short cycles. Teams do not build everything at once. They finish one small piece, test it, and move on.
What makes it different:
Work gets built and tested in short sprints
Requirements can change without breaking everything
Teams talk every day instead of working alone
Feedback comes in early enough to act on
Quality gets checked every sprint
Agile Process Model in Software Engineering
The agile process model in software engineering runs on a repeating cycle of one to four weeks.
Plan : team picks work and sets priorities
Design : approach agreed before coding starts
Build : developers code while testers write tests
Test : tests run all the way through
Review : working software shown to stakeholders
Retrospect : team talks about what to improve Each cycle the product gets better.
Agile Principles
The agile software development model follows twelve principles. The key ones are:
Deliver working software early and often
Welcome change even late in the project
Developers and business people work together daily
Working software is the best sign of progress
Reflect often and adjust to improve
These are not strict rules. They are a way of thinking.
Test Driven Development
Test driven development is called TDD. You write the test before you write the code. Three simple steps:
Red — write a test for something that does not exist. It fails.
Green — write just enough code to pass the test.
Refactor — clean the code. Make sure the test still passes.
Why TDD works in agile:
Bugs get found before more code piles on top
Code stays simple and easy to read
Changes are safe because tests catch what breaks
The test suite grows stronger every sprint
Behaviour Driven Development
Behavior driven development is called BDD. It builds on TDD. Tests are written in plain words anyone can read.
Three simple parts:
Given — what is true at the start
When — the action that happens
Then — the expected result
Example: Given a user is logged in. When they click checkout. Then the order page appears.
Why BDD helps:
Anyone on the team can read and check the tests
Problems get spotted before coding starts
Tests act as clear records of how the system works
Teams work better because everyone understands the goal
TDD tests the code. BDD tests the behaviour. Both work best together.
Agile Model Advantages
Faster delivery — working software ships every sprint
Easy to change — new requirements do not break the project
Better quality — bugs get caught and fixed early
Less risk — small releases mean small problems
Happy clients — they see progress and give feedback throughout
Always improving — each sprint gets better than the last
Agile Model Disadvantages
Hard to plan dates - firm end dates are tough to set upfront
Needs full team effort - disengagement breaks the model
Docs get skipped - teams sometimes forget to write things down
Scope can grow - flexible plans lead to too many new features
Not for fixed projects - if nothing can change, agile adds extra work
Takes time to learn - TDD, BDD, and sprint rituals have a learning curve
How Baseliner.ai Supports the Agile Software Development Model
Agile gives teams a way to work. Baseliner.ai gives them data to work smarter.
Most sprints go wrong slowly. Estimates drift. Scope grows. No one notices until it is too late. Baseliner.ai stops that:
Builds sprint baselines from real data, not guesses
Tracks actuals vs estimates live every sprint
Syncs with Jira so no one updates things twice
Sends alerts when scope changes put goals at risk
Agile works best with clear visibility. Baseliner.ai makes that happen.
Final Thoughts
The agile software development model is more than a process. It is a new way to think about building software.
Teams that do it well share the same habits:
They test early and fix problems fast
They welcome feedback and act on it
They deal with issues in the sprint, not after
They get a little better every single cycle
TDD keeps code clean. BDD keeps teams aligned. Agile keeps everything moving.
FAQs
Q1. What is the agile software development model?
A way to build software in short sprints. Teams test as they go, adjust when things change, and ship working software every cycle.
Q2. What are agile principles?
Twelve ideas from the Agile Manifesto. Deliver early, welcome change, work together daily, and keep improving.
Q3. What is test driven development in agile?
Writing the test before the code. The Red-Green-Refactor cycle keeps code clean and catches bugs early.
Q4. What is behaviour driven development in agile?
Writing tests in plain Given-When-Then language. It keeps the whole team aligned on what the software should do.
Q5. What are the advantages and disadvantages of the agile model?
Advantages are speed, flexibility, and quality. Disadvantages are hard deadlines, scope creep, and a learning curve for TDD and BDD.
