🔍 Factory Method vs Abstract Factory

✅ Purpose of Comparison

Both Factory Method and Abstract Factory are creational patterns used to encapsulate object creation. However, they differ in scale, responsibility, and intended use. This page compares their structure and use cases to clarify which pattern suits a given scenario.

✅ Comparison Overview

Aspect	Factory Method	Abstract Factory
Focus	Creation of a single object	Creation of a family of related objects
Structure	Abstract method in base class creates product	A factory interface creates multiple product types
Extensibility	Easy to add new product types	Good for managing multiple object types across families
Coupling	Low (based on a product interface)	Higher complexity but clearer coordination across product sets
Typical Use	When subclass decides what to instantiate	When consistent object families are required

✅ Similarities

• Both abstract the instantiation process to reduce dependency on concrete classes.
• Both improve extensibility by centralizing creation logic.
• Both adhere to the Open/Closed Principle, allowing extensions without modification.

✅ Key Differences

Aspect	Factory Method	Abstract Factory
Product Scope	Single product	Multiple related products (families)
Client Interaction	Subclass decides what to return	Factory provides families via interface
Usage Complexity	Simpler	More structured but heavier setup
Flexibility	Easy to plug different product implementations	Maintains consistency across related components

✅ UML Class Diagrams

Factory Method Pattern

Abstract Factory Pattern

✅ Practical Design Notes

• ✅ Use Factory Method when you need a flexible way to create one type of object at a time (e.g., single plugin or handler).
• ✅ Use Abstract Factory when object consistency matters, like building a UI theme or cross-platform toolkit.
• 🔁 Factory Method can be part of Abstract Factory’s internal structure to create individual items.

✅ Summary

• Factory Method encapsulates how to create a single object.
• Abstract Factory provides a group of related object creators.
• Abstract Factory is ideal when multiple coordinated products must be consistent.
• Choose based on the scope of creation: if you need consistency across multiple products, go with Abstract Factory; otherwise, Factory Method may be sufficient.