Q: Explain about 'Data Structure-Oriented Design (Early 70s)'
- Soon it was discovered:
- it is important to pay more attention to the design of data structures of a program
* than to the design of its control structure.
- Techniques which emphasize designing the data structure:
- derive program structure from it:
* are called data structure-oriented design techniques.
- Example of data structure-oriented design technique:
- Jackson
* developed by Michael Jackson in 1970s.
- JSP technique:
- program code structure should correspond to the data structure.
- In JSP methodology:
- a program's data structures are first designed using notations for
* sequence, selection, and iteration.
- Then data structure design is used :
* to derive the program structure.
- Several other data structure-oriented Methodologies also exist:
- e.g., Warnier-Orr Methodology.
Data Flow-Oriented Design (Late 70s)
- Data flow-oriented techniques advocate:
- the data items input to a system must first be identified,
- processing required on the data items to produce the required outputs should be determined.
- Data flow technique identifies:
- different processing stations (functions) in a system
- the items (data) that flow between processing stations.
- Data flow technique is a generic technique:
- can be used to model the working of any system
· not just software systems.
- A major advantage of the data flow technique is its simplicity
