Modular Design

Key aspects of modular design include:

• Interchangeability: Modules can be easily swapped or replaced without disrupting the entire system.
• Standardization: Modules typically follow standards to ensure compatibility with other components.
• Independence: Each module operates independently, minimizing the impact of changes in one module on others.
• Reusability: Modules can be reused across different systems, reducing development time and costs

Modular design is an approach that breaks down a system or product into smaller, independent parts called modules. These modules can be independently created, modified, and managed, allowing for greater flexibility and efficiency in design and production

Modular Design

For example, in a class, high cohesion would mean that all methods and properties are tightly related to the class's main purpose. If a class is responsible for handling user authentication, all of its methods would deal with login, registration, or password recovery.

• High cohesion: A module performs a single, focused task or closely related tasks. This improves clarity and maintainability.
• Low cohesion: A module performs multiple, unrelated tasks, making it harder to maintain and understand

Cohesion refers to how closely related and focused the responsibilities of a single module or component are. In software design, a highly cohesive module means that all of its parts work together to achieve a specific, well-defined task. Cohesion is desirable because it makes the module easier to understand, maintain, and reuse.

Cohesion

For example, if Module A directly interacts with Module B's internal workings, they are tightly coupled. In contrast, if Module A only interacts with Module B through a well-defined interface, they are loosely coupled.

• Tight coupling: Modules are heavily dependent on each other, leading to reduced flexibility and making the system harder to modify.
• Loose coupling: Modules are minimally dependent on each other, allowing for easier changes, maintenance, and reusability.

Coupling refers to the degree of dependency between two modules or components. If two modules are tightly coupled, they are highly dependent on each other, meaning a change in one module may require changes in the other. Loose coupling is preferred because it allows modules to be more independent and easier to change without affecting other parts of the system.

Coupling

With layered architecture, the system is divided into a number of layers, each of which is responsible for a different task and interacts with the layers above and below it. This design pattern encourages modularity, concern separation, and flexibility, which makes the system simpler to test, maintain, and grow. Four layers make up the layered architecture: presentation, application, domain, and infrastructure. Each layer is in charge of a certain task and only interacts with the layers directly above and below it. The system becomes more modular and is simpler to test and maintain because to this pattern's ability to clearly separate concerns.

Layered Architecture

Modularity It is simpler to scale and reuse components across several levels and applications since each layer may be built and tested independently of the others. Flexibility It is simpler to scale and reuse components across several levels and applications since each layer may be built and tested independently of the others. Scalability The infrastructure layer may be easily scaled horizontally by adding additional instances. Reusability Because components may be reused between layers and applications, the layered architecture speeds up development and lowers costs.

Advantages of Layered Architecture