Flow Charts
March 29th, 2009What is a flow chart? The flow chart is a means of visually presenting the flow of data within the information processing system, the performed operations and their sequence. In other words, the flow chart describes what operations and in what sequence are required to solve a given problem. This modeling technique was first introduced in the 1940s and has later become popular in structured development and business modeling.
Flow charts are used to facilitate communication between programmers and business people and are usually created at the early stages of a project to illustrate possible ways of solving a particular problem. They are especially helpful in understanding the logic of complicated and lengthy processes. Once the flow chart is created, it becomes easy to code the program in any high level programming language. In general, they can be helpful in explaining the inner mechanics of a process to others.
The flow chart can be compared to the blueprint of a building. An engineer must have a blueprint to start constructing a building. Similarly, a software engineer or systems architect draws a flow chart prior to writing a computer program. The flow chart is drawn according to defined rules and using standard flow chart symbols defined by the American National Standard Institute (ANSI), Inc.
A typical flow chart may have the following kinds of symbols: Start and End symbols (oval or rounded rectangle), Arrows that show flow of control, Processing steps (rectangle) that represent activities or tasks, Input/Output (parallelogram) that represent printed reports and data storage options, Decision (diamond or rhombus) which represent decision points, and Page Link Markers (circle) that represent a link to another point in a large chart. All symbols are connected with
arrows according to the internal logic of the process. Flow charts may also contain reciprocal links (loops) that represent iterative processes.
Any vector-based drawing program or even some word processing programs can be used to create flow charts. Specialized charting software usually comes with predefined libraries with more than 2000 vector symbols. You can create a wide range of diagrams using templates, shapes, and drawing tools while working in the user-friendly and relatively easy-to-use environment. It supports many kinds of charts beyond basic such as: organizational charts, business process, UML diagrams, work flows, program structures, network diagrams, chart and graphics, mind map, directional maps, and database diagrams.
Some of the advantages of using flow charts include: better communication, effective analysis, proper documentation, efficient coding, proper debugging, and efficient program maintenance. The limitations, on the other hand, are: it’s hard to illustrate complex logic, alterations and modifications are not that easy, text only reproduction of graphical symbols and their relationships is difficult, and the essentials of what is done can easily be lost in the technical details of how it is done.