# Decomposition

**Decomposition** in software design is the process of breaking down a complex system into smaller, more manageable components. This helps in understanding, designing, and maintaining the system by dividing it into **modules**, **functions**, or **subsystems**, each handling a specific part of the overall functionality.

For example, in a **Data Flow Diagram (DFD)**:

* **Level 0 (Context Diagram)** represents the entire system as one process.
* **Level 1 DFD** decomposes that single process into multiple sub-processes.

Decomposition improves **modularity, reusability, and scalability**, making large systems easier to develop and maintain.

## Example - Educational Product

### Main Function

Decompose the project into smaller modules

```python
def educational_product():
    DEVELOP_USER_MANAGEMENT_MODULE()
    DEVELOP_CONTENT_DELIVERY_MODULE()
    DEVELOP_PERFORMANCE_ANALYSIS_MODULE()
```

After developing each module, integrate them

```python
def INTEGRATE_MODULES()
```

### Module 1: User Management

```python
def DEVELOP_USER_MANAGEMENT_MODULE():
    # Handle user registration
    HANDLE_USER_REGISTRATION()
    
    # Handle user authentication
    HANDLE_USER_AUTHENTICATION()
    
    # Handle profile management
    HANDLE_PROFILE_MANAGEMENT()
```

```python
def HANDLE_USER_REGISTRATION():
    # (Details of user registration process)
```

```python
def HANDLE_USER_AUTHENTICATION():
    # (Details of user authentication process)
```

```python
def HANDLE_PROFILE_MANAGEMENT():
    # (Details of profile management process)
```

### Module 2: Content Delivery

```python
def DEVELOP_CONTENT_DELIVERY_MODULE():
    # Present educational content to the users
    DELIVER_EDUCATIONAL_CONTENT()
    
    # Provide questions related to the content
    PRESENT_QUESTIONS()
```

```python
def DELIVER_EDUCATIONAL_CONTENT():
    # (Details of content delivery process)
```

```python
def PRESENT_QUESTIONS():
    # (Details of presenting questions process)
```

### Module 3: Performance Analysis

```python
def DEVELOP_PERFORMANCE_ANALYSIS_MODULE():
    # Track user progress
    TRACK_USER_PROGRESS()
    
    # Analyse performance metrics
    ANALYSE_PERFORMANCE_METRICS()
```

```python
def TRACK_USER_PROGRESS():
    # (Details of tracking user progress)
```

```python
def ANALYSE_PERFORMANCE_METRICS():
    # (Details of analyzing performance metrics)
```

### Integration

```python
def INTEGRATE_MODULES():
    # (Details of integrating the modules)
```

### Execution

```python
def main():
    educational_product()
```