A DFD is used in system analysis and design as a system modelling tool. It consists of 4 elements; the process, flow, store and terminator, in which the process is the most important element. Advantages include:
- Specific Process:
A process describes a program function and data flow diagrams provide simple names and numbers to describe the specific program function. By numbering the process and keeping the process names simple, the systems analyst can easily and accurately reference the specific process. Eg. Calculate Interest Rate.
- Clarity of flow:
A data flow diagram shows a flow as a curved or straight arrow line. The purpose of the arrow line is to show the source and the arrow points to the next process, store, or terminator. This can help ensure all input and output has occurred.
- Appropriate Data Store:
A data flow diagram shows a store as two parallel lines. A data flow diagram can aid a systems analyst to decide if the data store has the recommended input data to be processed to generate the amount of output that is needed.
- Levels of Data Flow Diagram:
A data flow diagram has many levels that help a systems analyst review a system, process by process. the first level contains only one process and the further along you go the more and more that gets done. This aids the systems analyst to break apart the details easily and determine any problems that may occur in a system.
A flowchart is a diagram that represents the organization and flow of a certain process. It shows steps as boxes or levels that connect by lines or arrows. Each box contains a thought or action, and the arrows provide flow and direction. Flowcharts provide a streamlined way to organize, analyze, design and document. Advantages include:
- Visual Representation:
A flowchart provides a visual representation of a concept and can help make it clear. In many ways, a flowchart serves as a blueprint for the information you are presenting. Presentations are often conceptual, but a flowchart helps to organize and present your thoughts. Talking about a subject without offering graphics may be less effective. For example, if you are presenting a plan to reorganize a sales department, a flowchart can clearly show your ideas for the new department hierarchy and the timeline for the restructuring.
Flowcharts help keep a project organized. In the initial stages of any project, it can be difficult to keep things together. A flowchart will help you identify and manage key components of your project and avoid missing any elements. For example, computer programmers frequently use flowcharts to identify the individual steps of a program and avoid missing key factors, regardless of its complexity.
- Flexibility and Control:
A flowchart is relatively easy to prepare. A simple pencil and paper will do the trick, or there are software programs that will help you create a professional looking flowchart. Flowcharts are flexible and can be extremely complex or simple, depending on your needs. Also, they can change and evolve as your project develops and grows. The bottom line is that you’re in control, and the method of charting is up to you.