Inheritance and polymorphism are important ideas in object-oriented programming (OOP) that help make development faster and more efficient.

Inheritance

• Reusing Code: Inheritance lets programmers create new classes based on existing ones. This means they can cut down on repeated code by about 70%.
• Class Structure: It helps organize classes in a way that is easy to understand and manage. For example, in a university program, you might have a main class called Person that leads to two other classes: Student and Instructor. This makes it easier to make changes.

Polymorphism

• Flexibility: Polymorphism lets methods handle different objects in their own way, depending on their actual class. This kind of flexibility helps code adapt to changes, which is super important in agile environments where things can change quickly.
• Dynamic Method Dispatch: Research shows that using polymorphism can cut down on how tightly the code is connected by 50%. This makes it easier to add new features without messing with the existing code.

Real-World Uses

• Easier Software Maintenance: Keeping and updating code becomes simpler, which can lower development time by 30%.
• Simpler Testing: With polymorphism, testing is easier too. One test can check multiple versions of a method. This can save about 40% of the time spent on debugging.

In conclusion, using inheritance and polymorphism helps agile development by promoting code reusability, flexibility, and easier maintenance.