Intro to DFD 1

What is the main purpose of Data Flow Diagrams?

• To write code

• To play games

• To communicate with users and managers

• To create visual art

Which of the following is NOT a symbol used in Data Flow Diagrams?

• Source/Sinks

• Processes

• Data Centers

• Data flows

What does an External Entity represent in a Data Flow Diagram?

• People or organizations that send or receive data

• Transformations performed on data

• Permanent data used by the system

• Data in motion

What do Data Stores represent in a Data Flow Diagram?

• Data in motion

• Permanent data used by the system

• Processes performed on data

• People or organizations that send or receive data

Which of the following is true about Processes in Data Flow Diagrams?

• They are represented by double-headed arrows

• They only transfer input to output

• They are external entities

• They can create new data

What is the purpose of Decomposition of DFD?

• To combine all DFD fragments into one diagram

• To create a context diagram

• To break down a level 2 process

• To show the layers of abstraction

What is a good style in drawing DFD?

• Creating new data in processes

• Minimizing crossed lines

• Using meaningless names for data flows

• Starting from detailed diagrams and moving upwards

What is the purpose of a Context Diagram in DFD?

• To address only one process

• To validate DFDs with users

• To show the layers of abstraction

• To represent the major information flows

What is the rule for Level 0 Diagram in DFD?

• Multiple processes represent the entire system

• Processes can create new data

• Data arrows show input and output

• Data Stores are shown within the system

How should you create DFDs according to the text?

• Create a preliminary Context Diagram first

• Validate DFDs before creating fragments

• Identify Use Cases after creating Level 0 diagram

• Start from Level 2 and move downwards