Context Diagram
- consist of one process and draw veil from a system
- Is high level from the DFD that drawing all input to the system and output from system
- to limit system with boundary (drawing with break line)
- May not have a storage
Nol Diagram
- drawing from DFD process
- give the opinion as comprehensive about the system that to take, showing function or prime process that there is, flow data and external entry
- on this level may be have data storage
- for process that not detail again on the next level then to add symbol ‘ * ’ or ‘ P ‘ on the end number process
- balancing from input and output between 0 diagram with the context diagram must maintain
Detail Diagram
- is the diagram that apart process what that there is in 0 diagram or on level
- In one level good not be found more from 7 process and maximal 9, if more then must do decompositions
Process Specification
- Every process in DFD must have a process specification
- On the top level, method which used for describing process can using descriptive sentence
- On the more detail level that is on most under process (functional primitive) is need more structured specification.
- Process specification will be manual for programmer in making a program (coding)
- Method which used for process specification: part of process in a story form, decision table, decision tree.
Outside Unit
- Something out of system, but it give data into the system or give data from system
- Symbolized with notation box
- External entity is not include a part of system
- Naming :
- Terminal’s name is a noun
- Terminal mustn’t have same name except it is a same object
Data flow
· Is the place for information flowing
· Described by straight line which connecting components from system
· Data flow pointed by an arrow and line named depends on data flow that flowing
· Data flow flowing between process, data storage and showing data flow from incoming data for system
Data flow 2
· Giving name manual :
· Data flow’s name such as some word’s flow connect with connected line
· There’s no data flow that has a same name and name’s giving must describe the content
· Data flow from some elements can declare as a group element
· Avoid using word data and information giving data flow a name
· You must write the data flow name completely
Data flow 3
Other rule
· Data flow’s name which come into a process must not same with data flow’s name which come out from that process
· Data flow which come in or out from data storage not have to given name if:
· Simple data flow and easy to understand
· Data flow describing all of data item
· There must no data flow from terminal to data storage or the contrary because terminal is not part of system, terminal and data storage connection must pass through process
Process
- Process is what doing by system
- Process can turn data or incoming data flow become an outcome data flow
- Process has function in transforming one or more incoming data become one or more outcome data fits with needed specification
- Each process has one or more income and produce one or more outcome
- Process is also called bubble
Process 2
- Manual name given process:
- Process name from verb and noun which describe function of that process
- Do not use process word as a part of bubbles name
- There’s must no process which has a same name
- Process must given number. Number series must follow the stream or process number, but series numbers doesn’t mean its an absolute chronological series process
Data saved
- Data storage is data saved place in a system
- Symbolized with a pair of one or two row lines with one side open
- Process can take data from or give data to database
- Giving name manual:
- Name must describe data storage
- If name has more than one word so must given connect sign
Data Dictionary
- Has a function to help system subject for translate the application with detail and organize every element data which being used by system absolutely so the subject and system analyze has same basic definition about income, outcome, saved, and process
- On analysis phrase, data dictionary used as communication tools between system analysis and user
- On designing system phrase, data dictionary used for designing input, report, and database
- Data flow in DAD is global, more detail explanation can be see on data dictionary
Data Dictionary 2
· Data dictionary is including such things:
· Data flow’s name: must noted so readers who needs more explanation about data flow can search for it easily
· Alias: Alias or other name could be written if there’s so
· Data shape : used for organizing dictionary data dictionary to their function when designing system
· Data flow: show where data flows from and where data goes
· Explanation : give an explanation about meaning of data flow
Balancing in DFD
· Income and outcome data flow from one process must same with income and outcome data flow from detail process in level under them
· Income and outcome data flow from one process must same with income and outcome data flow from that detail process
· The number and name of outside entity from a process is same as the number and name from outside entity from that detail process
· Things that must be concern on DFD which has more than one level:
· Output and input must be balance from one and next level
· Balance between level 0 and 1 can looked on the input/output from data stream to or from level 0 terminal, balance between level 1 and 2 looked on the input/output from data system to/from the recent process
· Data flow name, data storage, and terminal in each level must same if the object same
Avoid in DFD
- Data flow not from outside entity and direct to other outside entity without any process
- Data flow not from saved data direct to outside entity without any process
- Data flow not from saved data direct to other saved data without any process
- Data flow not from one process direct to one saved data or the opponent / must be avoided
