Flow charts are constructed by using specific graphical symbols connected by arrows to represent the sequence of steps, decisions, and connections in a process or algorithm.
The fundamental principle of constructing a flowchart is following a strict rule regarding the type of symbols used for representing each step. These symbols have specific meanings, representing the start, process, connectors, input, output, end, etc. These symbols are represented using different shapes such as a circle, diamond, oval, arrow, and the like.
Understanding Flowchart Symbols
Each shape used in a flowchart has a distinct purpose, allowing anyone familiar with flowchart standards to understand the diagram's logic. Here are some common symbols and their meanings:
| Shape | Symbol | Meaning | Purpose |
|---|---|---|---|
| Terminator | Start/End | Indicates the beginning or end of a process. | |
| Process | Operation/Activity | Represents a step in the process. | |
| Decision | Decision Point | Indicates a point where a decision must be made (typically Yes/No or True/False), leading to different paths. | |
| Input/Output | Data Input or Output | Shows where data is entered into the process or results are output. | |
| Connector | Off-page or On-page Connector | Used to connect different parts of a flowchart, either on the same page or across pages. | |
| Arrows | Flow Line / Direction | Indicate the direction of the process flow from one step to the next. |
The Construction Process
Building a flowchart typically involves these steps:
- Define the Process/Scope: Clearly identify the process or system you want to chart. Determine the starting point and the ending point.
- Identify Key Steps: List all the individual steps, activities, decisions, inputs, and outputs involved in the process in sequential order.
- Select Appropriate Symbols: Choose the correct flowchart symbol for each identified step based on its function (Is it a start/end? A process? A decision? An input/output?).
- Draw the Flowchart:
- Begin with a Terminator symbol for the start.
- Place the symbols representing the subsequent steps in the logical order of the process.
- Use arrows (Flow Lines) to connect the symbols, showing the exact path and direction the process takes from one step to the next. Arrows typically flow from top to bottom or left to right.
- Use the Decision symbol for points where the flow can diverge, drawing separate arrows for each possible outcome (e.g., one labeled "Yes" and one labeled "No").
- Add Connector symbols if the flowchart spans multiple pages or requires jumping between non-adjacent points on the same page to maintain readability.
- End the flowchart with a Terminator symbol.
- Review and Refine: Check the flowchart to ensure it accurately represents the process, is easy to follow, and uses symbols correctly according to the rules.
By adhering to the standard set of symbols and connection rules, flowcharts provide a clear, visual representation of complex processes, making them easier to analyze, understand, and improve.
