DFD are carried in which of the phases

Data Flow Diagrams (DFDs) are typically used in the analysis phase of the system development life cycle. Here are the steps:

1. Requirement Gathering: In this phase, the requirements for the system are collected and documented. This is where the need for a DFD might be identified.

2. Analysis: This is the phase where DFDs are most commonly used. The collected requirements are analyzed and the system's flow of data is charted using DFDs. This helps in understanding how the system should work and how data moves through it.

3. Design: In this phase, the DFDs created in the analysis phase are used to design the system's architecture. The DFDs help in identifying the necessary components and their interactions.

4. Implementation: The system is built in this phase based on the design. The DFDs can serve as a reference to ensure the system is built as intended.

5. Testing: The system is tested to ensure it works as expected. The DFDs can be used to understand what the system should do and to create test cases.

6. Maintenance: After the system is deployed, it needs to be maintained. The DFDs can be used to understand the system when changes are needed.

So, DFDs are carried in the analysis phase but can also be used in the subsequent phases.