1. System Design By
Kustanto

2. Process modeling (structured analysis and design) is an analysis and design technique that describes processes that transform inputs into outputs
A process model is a formal way of representing how a business operates

3. What is system design????
System Design is to create a technical solution
that satisfies the functional requirements for the system.

4. Tools Several tools used in the design of systems are:
Data Flow Diagram,
Data dictionary,
Context diagram,
Event list,
Process spesification.

5. Data Flow Diagrams

6. Data Flow Diagram
Data flow diagram shows business processes and the data that flows between them
A diagram to show how data is captured, processed , stored and distributed within a system.
This is generally represented during the analysis stage of a project, but can be further refined during the design stage to show more detail of how the system functions.

7. DFD Elements and symbol
PROCESS
Number
An activity or function performed for a specific business reason
This can be a computerised or manual transformation
Name
Every process has:
Element
A number (for identity process)
A name function from process(verb phase and object)
A description one or more output data flow
Usually one or more input data flow
Example:
1.1
Check patient status

8. DFD Elements and symbol
DATA FLOW
Name
Illustrates the data flow from one process to anothe
A single piece of data or a logical collection of data
Always starts or ends at a process
Element
Every data flow has:
A name (a noun)
A description one or more connections to aprocess
Example:
Patient name

9. DATA STORE Every data store has:
A collection of data that is stored in some way (database)
Element
Every data store has: D1
Name
A number
A name
Example: D1
Patient

10. EXTERNAL ENTITY Every external entity has:
A person, organization, or system that is external to the system but interacts with it
Element
Every external entity has:
A name
Example:
Patient

11. Reading a DFD

12. Context Diagram First DFD in every business process
Shows the context into which the business process fits
Shows the overall business process as just one process (process 0)
Shows all the external entities that receive information from or contribute information to the system

13. Level 0 Diagram
Shows all the major processes that comprise the overall system – the internal components of process 0
Shows how the major processes are interrelated by data flows
Shows external entities and the major processes with which they interact

14. Level 1 Diagrams
Generally, one level 1 diagram is created for every major process on the level 0 diagram
Shows all the internal processes that comprise a single process on the level 0 diagram
Shows how information moves from and to each of these processes
If a parent process is decomposed into, for example, three child processes, these three child processes wholly and completely make up the parent process

15. Level 2 Diagrams
Shows all processes that comprise a single process on the level 1 diagram
Shows how information moves from and to each of these processes
Level 2 diagrams may not be needed for all level 1 processes
Correctly numbering each process helps the user understand where the process fits into the overall system

16. Level 3/4 diagram
IF it is necessary to produce a level 3 or level 4 diagram, the same steps would be followed as used when constructing the Level 1 diagram

17. Relationship Among DFD levels
Context diagram
Level 0 diagram
Level 1 diagram
Level 2 diagram

18. Example

19. Expert System DBD & Tifoid
Context Diagram
Data diseases, data symptom, data measuremnt of symptom, data rule, data login
Data diseases,
Data symptom
Expert System DBD & Tifoid
Expert
(Doctor)
Visitor
/User
Report data (diseases, sympton, measurement of symptom, rule patient)
Data patient
2/16/2019

20. Level 0 DFD of export system DBD & Tifoid
Expert System DBD & Tifoid
Top level
Level 0
1.0
Expert data
2.0
Diseases data
3.0
Symptom data
4.0
Rules data
5.0
Patient data
6.0
Report
2/16/2019

21. Level 0 DFD of export system DBD & Tifoid
1.0
Login & Password
Username & passd D1
Username & password
Diseases data
Export (Doctor) D2
Diseases
2.0
Diseases data
Symptom data D3
Symptom
Measurement data D4
Measurement
3.0
Symptom data
Rules data D5
Rules
4.0
Rules data
Rules data D7
conclusion
6.0
Report detection of diseases
Measurement data
Visitor/ user
Report the detection of diseases
Symptom data
Diseases data
Patient data
Patient data
Entry Patient data
5.0
Patient data D6
Patient
2/16/2019

22. Do’s and Don’ts when constructing a Data Flow Diagram 

23. Do’s and Don’ts when constructing a Data Flow Diagram 

24. Do’s and Don’ts when constructing a Data Flow Diagram 

25. . Context or Level 0 Diagram
example of how Data flow diagrams would be used to model the logic of data flows in a fast food burger bar.
. Context or Level 0 Diagram
Identify where data is captured from
Identify where data is distributed to
Describe the overall process
Map these out in a diagram using the correct symbols
Link them with data flows that are labelled

26. Level 0 Context diagram
CUSTOMER

27. Identify where data is captured from
Identify where data is distributed to
Describe the overall process
Map these out in a diagram using the correct symbols
Link them with data flows that are labelled

28. Level 0 Context diagram
KITCHEN
CUSTOMER
RESTAURANT MANAGER

29. Identify where data is captured from
Identify where data is distributed to
Describe the overall process
Map these out in a diagram using the correct symbols
Link them with data flows that are labelled

30. Level 0 Context diagram CUSTOMER KITCHEN Food ordering system
RESTAURANT MANAGER

31. Identify where data is captured from
Identify where data is distributed to
Describe the overall process
Map these out using the correct symbols
Link them with data flows that are labelled

32. Level 0 Context diagram CUSTOMER KITCHEN Receipt Customer Order
Receipt
Customer Order
Food Order
Food ordering system
Management Reports
RESTAURANT MANAGER

33. Constructing a Level 1 diagram
Identify and draw the processes that make up the Level 0 process
Allocate descriptions to these
Lay out the sources/sinks and data flows from the Level 0 diagram
Draw in any data stores used in the process
Link the new processes and data stores with named data links

34. Does this show enough detail?
Level 0 Context diagram
CUSTOMER
KITCHEN
Does this show enough detail?
Customer Order
Food ordering system
Food Order
Receipt
Management Reports
RESTAURANT MANAGER

35. Constructing a Level 1 diagram
Identify and draw the processes that make up the Level 0 process
Allocate descriptions to these
Lay out the sources/sinks and data flows from the Level 0 diagram
Draw in any data stores used in the process
Link the new processes and data stores with named data links

36. Level 1 diagram
These new processes may show a process which corresponds to actions such as :
Capturing data from different sources
Maintaining data stores
Producing and distributing data to different

37. Receive and transform Customer Food Order
1.0
Receive and transform Customer Food Order

38. Level 1 diagram
These may show a process which corresponds to actions such as :
Capturing data from different sources
Maintaining data stores
Producing and distributing data to different

39. Receive and transform Customer Food Order
1.0
Receive and transform Customer Food Order
3.0
Update Goods Sold file
2.0
Update Inventory file

40. Level 1 diagram
These may show a process which corresponds to actions such as :
Capturing data from different sources
Maintaining data stores
Producing and distributing data to different

41. 1.0 3.0 2.0 4.0 Receive and transform Customer Food Order
Update Goods Sold file
2.0
Update Inventory file
4.0
Produce Management Reports

42. Constructing a Level 1 diagram
Identify and draw the processes that make up the Level 0 process
Allocate descriptions to these
Lay out the sources/sinks and data flows from the Level 0 diagram
Draw in any data stores used in the process
Link the new processes and data stores with named data links

43. 1.0 3.0 2.0 4.0 CUSTOMER Customer Order Receipt KITCHEN Food Order
Receive and transform Customer Food Order
3.0
Update Goods Sold file
2.0
Update Inventory file
4.0
Produce Management Reports
RESTAURANT MANAGER
Management Reports

44. Constructing a Level 1 diagram
Identify and draw the processes that make up the Level 0 process
Allocate descriptions to these
Lay out the sources/sinks and data flows from the Level 0 diagram
Draw in any data stores used in the process
Link the new processes and data stores with named data links

45. CUSTOMER
KITCHEN
1.0
Receive and transform Customer Food Order
Customer Order
Food Order
Receipt
3.0
Update Goods Sold file
2.0
Update Inventory file D2
Inventory File
Goods Sold File D1
4.0
Produce Management Reports
RESTAURANT MANAGER
Management Reports

46. Constructing a Level 1 diagram
Identify and draw the processes that make up the Level 0 process
Allocate descriptions to these
Lay out the sources/sinks and data flows from the Level 0 diagram
Draw in any data stores used in the process
Link the new processes and data stores with named data links

47. CUSTOMER
KITCHEN
1.0
Receive and transform Customer Food Order
Customer Order
Food Order
Receipt
Goods
Sold
Inventory
Data
3.0
Update Goods Sold file
2.0
Update Inventory file
Inventory Data
Goods Sold Data D2
Inventory File
Goods Sold File D1
4.0
Produce Management Reports
Daily Inventory Depletion Amounts
Daily Goods Sold Amount
RESTAURANT MANAGER
Management Reports

48. End Of session