Advantages (+)

• Avoids compile-time implementation dependencies.
  • Instead of instantiating concrete classes directly, clients delegate instantiation to a separate factory object.
• Ensures creating consistent object families.
  • When an application supports creating multiple families of related objects, it must be ensured that a family of related objects is created and used together (see Sample Code / Example 3).
• Makes exchanging whole object families easy.
  • Because a factory object encapsulates creating a complete family of objects, the whole family can be exchanged by exchanging the factory object.

Disadvantages (–)

• Requires extending the Factory interface to extend an object family.
  • The Factory interface must be extended to extend a family of objects (to support new kinds of objects).
• Introduces an additional level of indirection.
  • The pattern achieves flexibility by introducing an additional level of indirection (clients delegate instantiation to a separate factory object), which makes clients dependent on a factory object.