Level 0 and 1 DFD and Related Concepts

What is the main focus of a Level 0 Data Flow Diagram (DFD)?

• Showing the processes in a sequential order

• Describing the detailed database structure of the system

• Representing data flows between external entities and the system as a whole

• Illustrating the hardware used in the system

What is a key element that must be present in any data flow diagram?

• User roles and permissions

• Data flows, processes, and external entities

• Programming code for each process

• A detailed hardware specification

Which of the following is true about data flows in a Level 0 DFD?

• They can represent physical objects like receipts or invoices.

• They must always have a direction and connect an external entity to the system or a process.

• They show how the system processes data internally.

• They depict the exact storage location of data.

Which of the following is a rule for creating Level 0 DFDs?

• Every data flow must connect directly to a data store.

• Processes are optional and may not always be needed.

• External entities must only interact with the system through data flows.

• Physical processing steps must be represented.

What is the purpose of a Level 0 DFD?

• To describe the physical layout of the system's components

• To break down the system into detailed processes

• To provide a high-level view of the system and its interactions with external entities

• To list all data types used in the system

Why must every data flow in a DFD be connected to a process?

• To ensure that the data is stored properly

• To show that processes transform data in some way

• To display the sequence of steps in a process

• To represent the network's physical structure

In the car hire company scenario, what does the process "Take Payment" represent in the Level 0 DFD?

• An external entity interacting with the system

• The storage location for payment data

• A transformation of input data (payment details) into output data (receipt)

• The entire car hire system

Why is it incorrect to show a direct data flow between two external entities in a DFD?

• External entities do not interact with each other.

• All data flows must pass through a process for transformation.

• irect flows increase the complexity of the diagram.

• External entities are not represented in Level 0 DFDs.

What would be the output data flow for the process "Generate Invoice" in the car hire company example?

• Driving license details

• Payment made by the customer

• Invoice sent to the customer

• Insurance details provided