Question

What are the differences between data flow diagrams and Flowcharts? What are their roles in IS? please can somebody type it out for me because i do not understand pictures

Answer 1

Difference between Data flow diagrams(DFD) and Flow charts

The main difference between DFD and Flowchart is that DFD is a graphical diagram that represents the data flow of a system while flowchart is a graphical diagram that represents the sequence of steps to solve a problem.

Developing software is a complex process, and it is difficult to write the program of the entire system directly. Therefore, it is necessary to model the system to get an understanding and then to program the modules. There are various diagrams that help to model the system. DFD and flowchart are two of them. DFD illustrates the inputs, outputs, how the data flows through the system and where data will be stored. On the other hand, a flowchart helps to illustrate the steps to solve the problem. It can be used as the basis to write the program.

Definition

DFD is a graphical representation of the flow of data through an information system, modelling its process aspects. In contrast, a flowchart is a diagrammatic representation that illustrates a solution model to a given problem. Thus, this explains the basic difference between DFD and flowchart.

Applicability

DFD can be used for complex systems. Although a flowchart is not very suitable for a complex system, it is applicable for small to medium programs. Hence, this is another difference between DFD and flowchart.

Usage

Moreover, their usage attributes to another difference between DFD and flowchart is their usage. DFDs help to understand the overview of the system without going into more details while flowcharts help to analyze, design and manage a program.

Role of DFD in IS

DFD graphically representing the functions, or processes, which capture, manipulate, store, and distribute data between a system and its environment and between components of a system. The visual representation makes it a good communication tool between User and System designer. Structure of DFD allows starting from a broad overview and expand it to a hierarchy of detailed diagrams. DFD has often been used due to the following reasons:

• Logical information flow of the system
• Determination of physical system construction requirements
• Simplicity of notation
• Establishment of manual and automated systems requirements.

Role of Flow chart in IS.

Each flow chart is concerned with one particular process or system. It begins with the input of data or materials into the system and traces all the procedures needed to convert the input into its final output form. Specialized flow chart symbols show the processes that take place, the actions that are performed in each step, and the relationship between various steps. Flow charts may include different levels of detail as needed, from a high-level overview of an entire system to a detailed diagram of one component process within a larger system. In any case, the flow chart shows the overall structure of the process or system, traces the flow of information and work through it, and highlights key processing and decision points.

Flow charts are an important tool for the improvement of processes. By providing a graphical representation, they help project teams to identify the different elements of a process and understand the interrelationships among the various steps. Flow charts may also be used to gather information and data about a process as an aid to decision making or performance evaluation. For example, the owner of a small advertising agency who hopes to reduce the time involved in creating a print ad might be able to use a flow chart of the process to identify and eliminate unnecessary steps. Though flow charts are relatively old design tools, they remain popular among computer programmers working on systems analysis and design. In recent years, many software programs have been developed to assist business people in creating flow charts.