EAT JACQUARD DESIGN SOFTWARE SOFTWARE

Their graphical representation makes it easier for designers and managers to get the pictorial idea of the system structure. HIPO diagrams are good for documentation purpose. It depicts the functions performed by system. It decomposes functions into sub-functions in a hierarchical manner. Analyst uses HIPO diagram in order to obtain high-level view of system functions.

EAT JACQUARD DESIGN SOFTWARE SOFTWARE

HIPO diagram represents the hierarchy of modules in the software system. HIPO model was developed by IBM in year 1970. HIPO (Hierarchical Input Process Output) diagram is a combination of two organized method to analyze the system and provide the means of documentation.

Control flow - A directed arrow with filled circle at the end represents control flow.Data flow - A directed arrow with empty circle at the end represents data flow.All sub-modules covered by loop repeat execution of module. Loop - A curved arrow represents loop in the module.Jump - An arrow is shown pointing inside the module to depict that the control will jump in the middle of the sub-module.It depicts that control module can select any of sub-routine based on some condition. Condition - It is represented by small diamond at the base of module.Library Modules are re-usable and invokable from any module. A control module branches to more than one sub-module. Module - It represents process or subroutine or task.Here are the symbols used in construction of structure charts. At each layer a specific task is performed. Structure chart represents hierarchical structure of modules. It breaks down the entire system into lowest functional modules, describes functions and sub-functions of each module of the system to a greater detail than DFD. It represents the system in more detail than DFD. Structure chart is a chart derived from Data Flow Diagram.

Higher level DFDs can be transformed into more specific lower level DFDs with deeper level of understanding unless the desired level of specification is achieved. Level 2 - At this level, DFD shows how data flows inside the modules mentioned in Level 1. Level 1 DFD also mentions basic processes and sources of information. Level 1 DFD depicts basic modules in the system and flow of data among various modules.

Level 1 - The Level 0 DFD is broken down into more specific, Level 1 DFD.

Level 0 DFDs are also known as context level DFDs.

Level 0 - Highest abstraction level DFD is known as Level 0 DFD, which depicts the entire information system as one diagram concealing all the underlying details.

Data movement is shown from the base of arrow as its source towards head of the arrow as destination.

Data Flow - Movement of data is shown by pointed arrows.

Data Storage - There are two variants of data storage - it can either be represented as a rectangle with absence of both smaller sides or as an open-sided rectangle with only one side missing.

Process - Activities and action taken on the data are represented by Circle or Round-edged rectangles.

Entities are represented by a rectangles with their respective names.

Entities - Entities are source and destination of information data.

It is more specific and close to the implementation.ДFD can represent Source, destination, storage and flow of data using the following set of components.

Physical DFD - This type of DFD shows how the data flow is actually implemented in the system.

Logical DFD - This type of DFD concentrates on the system process, and flow of data in the system.For example in a Banking software system, how data is moved between different entities.

Types of DFDДata Flow Diagrams are either Logical or Physical. DFD does not contain any control or branch elements. DFDs depict flow of data in the system at various levels.

The flowchart depicts flow of control in program modules. There is a prominent difference between DFD and Flowchart. The DFD does not mention anything about how data flows through the system. It is capable of depicting incoming data flow, outgoing data flow and stored data. Let us see few analysis and design tools used by software designers: Data Flow DiagramДata flow diagram is graphical representation of flow of data in an information system. Software analysis and design is the intermediate stage, which helps human-readable requirements to be transformed into actual code. These requirement specifications come in the shape of human readable and understandable documents, to which a computer has nothing to do. Requirement specifications specify all functional and non-functional expectations from the software. Software analysis and design includes all activities, which help the transformation of requirement specification into implementation.

Eat jacquard design software