A program flowchart is a diagram that uses standard ANSI symbols to show the step-by-step processing activities and decision logic needed to solve a problem. Flowcharts are created before a programmer begins writing the program. In concept, flowcharts are similar to an architect’s blueprint for a house. You need the blueprint before you can nail in the first 2*4 stud. After construction is underway, you may need to modify the blueprint. Similarly, the programmer may need to modify the flowchart during the process of creating the program. The flow of logic in a program flowchart normally goes from top to bottom and left to right. Arrows are used to show a change from those directions.
Although program flowcharts have some disadvantages – their preparation may be time-consuming and they can be many pages long- they are considered to be good tools for documenting the procedures to be used in the program, and they are often included in a program’s documentation package. Software packages are available that automate the process of drawing and modifying flowcharts.