Astah User's Guide

Data Flow Diagram


DFD


Create Diagram

  • Go to [Diagram] - [Data Flow Diagram]
    Create DFD
  • Create from the pop-up menu in the Structure Tree.


Change Notation

Astah's DFD support two notations - DeMarco or and Gane/Sarson. There are three ways to switch the notation.

  • Right-click on DFD and select [Diagram Notation] from its Pop-up menu.
    DFD
  • Pop-up menu of DFD in the Structure Tree
    DFD
  • DFD's Property View
    DFD
TIPS: Set Default Notation
You can change the default notation for your DFD from the System Properties.


Data Flow Diagram Tool Palatte

DeMarco

DFD in DeMarco

Gane/Sarson

DFD in Gane/Sarson

DeMarcoGane/SarsonButton
EREntityrelationidentify ieExternal Entity
relationidentifyrelationidentify ieProcessBox
relationnonidentifyrelationnonidentify ieDataStore
relationmanyAnchor
subtypeDataFlow
subtypeDataFlow (Both Arrows)
See Common tools.


External Entity

Select [External Entity] from the Tool palatte and click on a diagram.
Notation of External Entity varies depending on its number.

Single (DeMarco - Gane/Sarson)

External Entity
Plurai (DeMarco、Gane/Sarson)

External Entity



ProcessBox

Create a ProcessBox.

There are two ways to create ProcessBox.

  1. Double-click Data Flow Diagram.
  2. Select [ProcessBox] from the Tool palatte and click on a diagram.


Add ID

There are two ways to add ID to ProcessBox.

  1. Double-click on the upper part of the ProcessBox and directly enter.
  2. From [Base] tab of the ProcessBox in the Property view.


Add an Operator

There are two ways to add an Operator to ProcessBox.

  1. Double-click on the lower part of the ProcessBox and directly enter.
  2. From [Base] tab of the ProcessBox in the Property view.


Convert to UseCase

Right-click on the ProcessBox on DFD and select [Convert to UseCase].



DataStore

Select [DataStore] from the Tool palatte and click on a diagram.
Notation of DataStore varies on the number.

Single (DeMarco、Gane/Sarson)

External Entity
Plural (DeMarco、Gane/Sarson)

External Entity



Anchor

An Anchor is a symbol to connect to a Process in another Data Flow Diagram.



DataFlow

Create a DataFlow

Select [DataFlow] from the Tool palatte and click objects.

Datalow

Convert to ER Entity

Select [Convert to EREntity] from the DataFlow's Pop-up menu in the Structure Tree.