Sure! Here’s a simple comparative study of SDLC, Agile, and OOSAD in five important points:

### 1. **Development Process**
- **SDLC**: Follows a clear, step-by-step process with fixed phases (like planning, designing, and testing).
- **Agile**: Works in short cycles called sprints, allowing teams to adapt quickly to changes and feedback.
- **OOSAD**: Combines structured steps with a focus on using objects (like classes and objects in programming) to design systems.

### 2. **Involvement of Stakeholders**
- **SDLC**: Involves stakeholders mainly at the beginning (requirements) and the end (testing), with little interaction in between.
- **Agile**: Involves stakeholders throughout the project, encouraging regular feedback to make sure the product meets their needs.
- **OOSAD**: Engages stakeholders during analysis and design, focusing on how different objects will work together.

### 3. **Flexibility**
- **SDLC**: Less flexible; making changes later in the process can be difficult and expensive.
- **Agile**: Very flexible; changes can be made at any time based on new information or feedback.
- **OOSAD**: Offers some flexibility, especially during the design phase, but is generally more structured than Agile.

### 4. **Documentation**
- **SDLC**: Requires a lot of documentation at every phase to keep track of progress and decisions.
- **Agile**: Focuses on delivering working software rather than heavy documentation, keeping it to a minimum.
- **OOSAD**: Provides important documents (like use cases and diagrams) to help guide development, but not as extensive as SDLC.

### 5. **Managing Risks**
- **SDLC**: Identifies risks mainly during the planning stage, which can be a challenge if issues arise later.
- **Agile**: Continuously looks for and addresses risks throughout the project, allowing for quick adjustments.
- **OOSAD**: Analyzes risks during the design phase, particularly how objects will interact and affect the system.

This summary highlights the key differences between the three approaches in an easy-to-understand way!