Data flow diagrams

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What is meant by a data flow diagram?: A diagram that shows where data comes from, where it is stored, how it is processed and where it goes
Which term describes someone or something that interacts with the system shown in a data flow diagram?: Entity
What is meant by a process in a data flow diagram?: Something that happens to the data as it moves through the system
Which component of a data flow diagram shows where processed records are held?: Data store
What is meant by a manual data store in a data flow diagram?: A store that is non-electronic, for example a paper file
Which term describes an arrow that shows records moving from one component of a system to another?: Data flow
Which form of notation is often used by database developers to explain how different data is connected?: A data flow diagram
A data flow diagram shows a rectangle labelled 1.0 Stock check. What does this symbol represent?: A process that data passes through
A data flow diagram includes a store labelled M1 Borrower records. What does the M1 tell you about this store?: The records are kept on paper
A process takes in only a customer surname but outputs a full invoice with items and prices. Which rule does this break?: Output data cannot contain more data than the input data
A data flow diagram shows a process box with three arrows going in and none coming out. Which rule has been broken?: A process must have at least one input and one output
A team is deciding exactly what a new system will include and what it will leave out. What can a data flow diagram help them to do?: Define the boundaries of the system
A bank's data flow diagram has dozens of processes and data stores. What is the main disadvantage of this diagram?: It can be very complex and difficult to understand
In a data flow diagram, an arrow points from a data store to a process. What does this show?: Data being taken out of the store
On a data flow diagram, an arrow goes straight from one entity to another entity. Why is this not allowed?: Every data flow must go to or from a process
Which piece of information about a system can a data flow diagram not show?: The hardware and software it needs
A process in a data flow diagram takes in a list of customer names and outputs exactly the same list of customer names. Which rule has been broken?: A process must change the data it receives

Data flow diagrams

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