Draw DFD diagrams for a hotel reservation System. You need to include at least the context diagram, Level-0 and all Level-1 diagrams except for “Report” process in Level-0. You have to use “Gane-Sarson notation” in Visio.
The correct answer and explanation is :
To create Data Flow Diagrams (DFDs) for a hotel reservation system using the Gane-Sarson notation in Microsoft Visio, we will need to follow a systematic approach. Here’s how the DFDs should be structured:
1. Context Diagram (Level 0)
- Purpose: This diagram represents the highest level of the system and shows the interactions between the system and external entities.
- External Entities: Guests, Hotel Staff, and the Payment System.
- Processes: A single process labeled “Hotel Reservation System” that encompasses all the activities.
- Data Flows:
- Guest submits reservation request to the Hotel Reservation System.
- Hotel Staff updates and manages the reservation system.
- Payment System processes payment for reservations.
- Reservation confirmation is sent back to the guest.
Explanation: The context diagram shows the external interactions and the overall scope of the system. It provides a simple overview of the system, excluding internal processes for now.
2. Level 0 DFD (Decomposing the Context)
- Processes: At Level-0, we will break the main “Hotel Reservation System” into a set of key processes.
- Process 1: Guest Reservation Request
- Process 2: Reservation Management
- Process 3: Payment Processing
- Process 4: Reservation Confirmation
- Data Flows:
- Guest Reservation Request: Includes guest details (e.g., name, dates, room type), which are sent to the Reservation Management process.
- Reservation Management: Communicates room availability to the guest, sends reservation data to Payment Processing, and manages room inventory.
- Payment Processing: Sends payment details to the Payment System and receives confirmation.
- Reservation Confirmation: Confirms reservation details back to the guest.
Explanation: The Level 0 DFD divides the core functionality of the system into manageable processes. Each of these processes corresponds to a major function of the hotel reservation system.
3. Level 1 DFD (Decomposing the Processes Further)
- Process 1: Guest Reservation Request:
- This is broken down into:
- Sub-process 1.1: Input Reservation Details (Guest inputs personal and reservation details).
- Sub-process 1.2: Validate Reservation (System checks availability).
- Process 2: Reservation Management:
- Sub-processes for managing room assignments, updating records, and handling changes.
- Process 3: Payment Processing:
- Sub-processes include validating payment methods, processing payment, and updating transaction records.
- Process 4: Reservation Confirmation:
- Sub-process for confirming the reservation and sending out the confirmation details to the guest.
Explanation: The Level 1 DFD dives deeper into the individual activities that occur within each process. Each sub-process performs a specific task, like validating room availability or processing payments, which are important for the operation of the reservation system.
Steps to Create DFDs in Visio (Using Gane-Sarson Notation)
- Context Diagram: Use a large process symbol (rectangle) labeled “Hotel Reservation System” and connect it to external entities using arrows (data flows).
- Level 0 DFD: Decompose the context diagram into multiple processes (rectangles) connected by data flows to show how data moves between processes, entities, and data stores.
- Level 1 DFD: Break down the processes in Level 0 into smaller sub-processes and indicate data stores.
In Visio:
- Start by using “Basic Flowchart Shapes”.
- Choose the “Process” symbol for the system’s processes.
- Use “External Entity” for entities like guests and hotel staff.
- Use “Data Flow” to represent arrows that show the movement of data.
- Add “Data Stores” (open-ended rectangles) to represent databases where reservation details or payment info are stored.
Explanation of the System Design
- Context Diagram is used to establish boundaries for the system, ensuring only relevant interactions are included.
- Level 0 identifies the major processes, ensuring the key activities (reservation, payment, and confirmation) are well-defined.
- Level 1 gives deeper insight into how each major process operates, helping developers understand the finer details of the system’s operations.
This hierarchical breakdown ensures clarity and helps in system analysis and future design stages.