Why Identifying classes from requirements in LLD? - Purpose & Use Cases

The Big Idea

What if you could turn confusing requirements into a clear, simple blueprint for your software?

The Scenario

Imagine you have a big list of features and rules for a new app written in plain text. You try to build the app by guessing what parts you need, writing code without clear structure.

You keep adding bits here and there, but soon the code is messy and confusing.

The Problem

Without clear classes, your code becomes a tangled mess. It's hard to find where things belong, and fixing one part breaks another.

Adding new features takes forever because you don't know where to put them. Bugs hide in the chaos, and teamwork becomes a nightmare.

The Solution

Identifying classes from requirements helps you spot the main objects and their roles early on.

This gives your design a clear shape, like sorting tools into labeled boxes. Each class has a purpose, making the code easier to build, understand, and change.

Before vs After

✗ Before

if user_is_logged_in:
    show_dashboard()
else:
    show_login()
# everything mixed in one place

✓ After

class User:
    def login(self):
        pass
class Dashboard:
    def display(self):
        pass
# clear roles separated

What It Enables

It enables building software that is organized, easy to maintain, and ready to grow without chaos.

Real Life Example

Think of designing a library system: by identifying classes like Book, Member, and Loan early, you create a clear map that guides the whole project smoothly.

Key Takeaways

Manual coding without classes leads to messy, fragile code.

Identifying classes organizes requirements into clear, manageable parts.

Clear classes make software easier to build, fix, and expand.