Payroll
Data Flow Diagrams * Graphically characterize data processes and flows in a business system
Basic Symbols * A double square for an external entity * An arrow for movement of data from one point to another * A rectangle with rounded corners for the occurrence of a transforming process * An open-ended rectangle for a data store
The four basic symbols used in data flow diagrams, their meanings, and examples
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Creating the Context Diagram * The highest level in a data flow diagram * Contains only one process, representing the entire system * The process is given the number 0 * Page 1 of 3
All external entities, as well as Major data flows are shown
Creating Child Diagrams * Each process on diagram 0 may be exploded to create a child diagram * A child diagram cannot produce output or receive input that the parent process does not also produce or receive * The child process is given the same number as the parent process * Entities are usually not shown on the child diagrams below Diagram 0 * If the parent process has data flow connecting to a data store, the child diagram may include the data store as well * When a process is not exploded, it is called a primitive process
Differences between the parent diagram (above) and the child diagram (below)
Page 2 of 3
Data Flow * Shows movement of data from one point to another * Described with a noun * Arrowhead indicates the flow direction * Represents data about a person, place, or thing
Steps in developing data flow diagrams
Developing Data Flow Diagrams Using A Top –Down Approach A. Make a list of business activities and use it to determine various * External entities * Data flows * Processes * Data stored
Basic Symbols * A double square for an external entity * An arrow for movement of data from one point to another * A rectangle with rounded corners for the occurrence of a transforming process * An open-ended rectangle for a data store
The four basic symbols used in data flow diagrams, their meanings, and examples
[Type a quote from the document or the summary of an interesting point. You can position the text box anywhere in the document. Use the Text Box Tools tab to change the formatting of the pull quote text box.]
Creating the Context Diagram * The highest level in a data flow diagram * Contains only one process, representing the entire system * The process is given the number 0 * Page 1 of 3
All external entities, as well as Major data flows are shown
Creating Child Diagrams * Each process on diagram 0 may be exploded to create a child diagram * A child diagram cannot produce output or receive input that the parent process does not also produce or receive * The child process is given the same number as the parent process * Entities are usually not shown on the child diagrams below Diagram 0 * If the parent process has data flow connecting to a data store, the child diagram may include the data store as well * When a process is not exploded, it is called a primitive process
Differences between the parent diagram (above) and the child diagram (below)
Page 2 of 3
Data Flow * Shows movement of data from one point to another * Described with a noun * Arrowhead indicates the flow direction * Represents data about a person, place, or thing
Steps in developing data flow diagrams
Developing Data Flow Diagrams Using A Top –Down Approach A. Make a list of business activities and use it to determine various * External entities * Data flows * Processes * Data stored