A data flow diagram (DFD) shows how information flows within an information system. A DFD is a representation of the data flow and does not imply the activity order. A DFD is a model of a real-world business system represented through a hierarchy of abstracts through leveling. Lower levels of a DFD reflect more detail, and higher levels of a DFD reflect less detail. A logical system diagram describes the business events that take place and the data required for each business event, focusing on what information is flowing and what information is transmitted. A DFD will not go into technical (hardware and software) aspects of the system; it will show inputs and outputs from external sources, showing the path of data and how it flows through the system.
Prompt
For this activity, you need to create a data flow diagram reflective of the following:
Your experience registering for a course and then following the process through payment (or using financial aid).
Access course catalog
- Review course options
Select course to register for
- Complete registration
- Pay for course
- Your DFD must include the listed processes and at least two subprocesses (levels) within two of the five main processes. Your diagram can reflect up to three levels: zero (the context diagram), one (subprocess), and two (functionality). The various levels of detail are:
- Level zero: Represents the overview of the entire system you are critiquing
- Level one: Breaks down the main functions of the system into smaller subprocesses
Level two: Further breaks down subprocesses of level one
Use the symbols from the Gane and Sarson symbol set needed to illustrate data flow within your diagram:
- External entity = Square ?
- Data flow = Arrow ?
- Process = Rounded square ?
Data stored = Rectangle ?
Specifically, you must address the following rubric criteria:
- Data Flow Diagram: Your diagram must be completed without any missing components. It needs to show how information flows within a system process. Remember: only DATA flows on data flows.
- Hierarchical Leveling: Whether your diagram has one or three levels, it needs to illustrate how each level is broken down into smaller business events.
- Data Flow Notation: Your diagram should include accurate and appropriate data flow notation. Whenever you are referring to a process, use a rounded square symbol. Whenever you are referring to data that is being stored, use a rectangle. It depends on the business process, but you may or may not have to use all Gane and Sarson symbols.
- Logical System Functionality: Your diagram also needs to illustrate how business events are broken down into smaller subprocesses.
Guidelines for Submission
Upload a .doc, .pdf, or .jpeg file of your diagram. You can use a tool of your choice to help you create the data flow diagram, but we recommend using Lucidchart, draw.io, or Microsoft Visio.
Getting Started in Lucidchart: The Basics
Visio 2016 Tutorial
Microsoft Azure Dev Tools for Teaching (link to access Visio)
Draw.io Quick Start Video Tutorial (1:35)
POST
some more resources in case you need help with diagramVideo: How to Draw Visio Process Flow Diagram (Step by Step Tutorial) opens in new window (6:10)A captioned version of this video is available: How to Draw Visio Process Flow Diagram (Step by Step Tutorial) (CC) opens in new window (6:10). In this video tutorial, you will learn the steps for creating a process flow diagram using Visio.As you watch, consider the following:What does a data flow diagram represent?What are the benefits and disadvantages of creating a data flow diagram?Video: Data Flow Diagrams – What Is DFD? Data Flow Diagram Symbols and More opens in new window (4:13) A captioned version of this video is available: Data Flow Diagrams – What Is DFD? Data Flow Diagram Symbols and More opens in new window (CC) (4:13). This video outlines what a data flow diagram is in terms of inputs and outputs of data. You will learn about the steps involved in making a data flow diagram, how one is used, and what the various symbols and notations mean. This video also provides you with a step by step tutorial using an automated diagramming tool.As you watch, consider the following:What are the steps involved in creating a data flow diagram?Why is it important to understand what the various symbols and notations mean?Video: System Diagram opens in new window (1:13)This video provides a description of basic system diagrams. It identifies the inputs and outputs of processes, and shows you where they would be documented within a system diagram and how that information can be used to identify the primary purpose of a business system. A video transcript is available here: IT 409 System Diagram Transcript opens in new window
