DFD

Data flow diagram
• called also data flow diagram (DFD)
• describe system distribution into module smaller
• will make user less will realize computer area to will understand system that be done

Diagram context
• consist of one process and describe scope from a system
• be level highest from DFD that describe entire input to system and outpur from system
• system is limitted by boundary (described by line broken offs)
• there may not be any storage (storage)

Zero diagram
• describe process from DFD
• give opinion according to comprehensive hit system that handled, show function or principal process, data current and eskternal entity
• in level this maked data existence storage
• for process is not detailed again in level furthermore so added simbol ‘*’ or ‘p’ by the end of process number
• balance input and output (balancing) between diagram 0 with context diagram must be taked care

Detail diagram
• merupaan diagram that elaborate what process is there in diagram zero or level at on it
• numberization level in DFD:
Name Level Name Diagram Number Proses
0 Context
1 Diagram 0 1.0, 2.0, 3.0, ...
2 Diagram 1.0 1.1, 1.2, 1.3, ...
3 Diagram 1.1 1.1.1, 1.1.2, ...

• in one level best not found more than 7 process and maximal 9, when more so dekomposition

Unitary outside
• something that beyond system, but he gives data into system or give data from system
• symbolized with notation box
• external entity doesn't belong part from system
• nomenclature:
1. terminal name shaped noun
2. terminal may not has name same except the object really same

Data current
• be place currences information
• described with straight line that connect component from system
• data current is showed with arrow direction and line is given name on data current that flow
• data current flows between process, data storage and show data current from data shaped input for system

Data current (2)
• name gift guide:
1. data current name that consist of several word currents related with line continues
2. there may not be any data current the name same and name gift must reflect its contents
3. data current that consist of several elements can be declared with element group
4. koid word use ‘data’ and ‘informasi’ to give name in data current
5. can may be data current name is written complete

Data current (3)
• rule other:
 data current name that come into a process may not equal to secretory data current name from process
 data flow that step into or out from data storage unnecessary given whose name:
• simple data current and easy understood
• data current describes entire item data

 there may not be any data current from terminal to data storage or on the contrary because terminal not part from system, terminal connection with data storage must pass process
Process
 process is what done by system
 process can cultivate data or data current enters to be data current out
 process functioned transformation one or several input data is one or several product data as according to desirable spesification
 every has one process or several inputs with produce one or several products
 process often also called bubble

Process (2)
 process name gift guide:
1. process name consists of verb and noun that reflect process function
2. don't use process word as part from name a bubble
3. there may not be any several process that has names same
4. process must be given number. sequence number can may be follow current or sequence process, but such sequence meaningless number absolutely is sequence process chronologically

Data savings
 data storage be existing data repository in system
 symbolized with a pair parallel line or two lines wrongly one sides side opened
 process can take data from or give data to database
 name gift guide:
1. name must reflect data storage
2. when does the name more than one word so be must be given sign continue

Data dictionary
 functioned to help system executant to interpret application in detail and organisation all data element that used system according to exactly so that user and has base explanation same about input, product, storage and process
 in analysis stage, data dictionary is used as a means of communication between system analyst with user
 in system planning stage, data dictionary is used to design input, report and databases
 data current in dad has global, explanation detailer visible in data dictionary

Data dictionary (2)
 data dictionary holds the followings:
1. data current name: must be registerred so that reader that need furthermore explanation about a data current can look for it easily
2. alias: alias or name other from data can be written if (there are) any
3. data form: used to group data dictionary into its use sewaktu system planning
4. data current: show from which data flows and where does data aim
5. explanation: give explanation about meaning from data current

Balancing in DFD
 data current that come into and out from one process must equal to data current that comes into and out from process details in level/stage at under it
 data current name that come into and out from one process must equal to data urrent name that enters to into and out from process details
 total and name entitas outside from a process must equal to total and name entitas outside from process details
 matters that must be payed in DFD that has more than one level:
1. must found balance input and output between one level and level next
2. balance between level 0 and level 1 seen in input/output from data current to or from terminal in level 0, while balance between level 1 and level 2 seen in input/output from data current to/from process concerned
3. data current name, data storage and terminal in every level must same if the object same

Prohibition in DFD
 data current may not from entitas outside direct aim entitas outside another without pass a process
 data current may not from direct data savings aim to entitas outside without pass a process
 data current may not from direct data savings aim another data savings without pass a process
 data current from one direct process aims another process without pass a data savings best/bisa may be avoided