A flowchart is a graphical way to show the logic of an algorithm.
While there is a technical and specific way of showing a flowchart, it isn’t required to logically get information across. Sometimes you’ll find them in jokes, or shared between non-technical people.
Clearly, based on the example, you can see how to follow the logic that is trying to be described.
Now, we can use a more technical method which allows us to share with others a more precise method of showing the logical flow.
Types of Blocks
Terminal Block
The Terminal Block is where we start or stop a flow chart. Some people will write in start or stop so people know for sure what it is doing.
It provides no logic to the flowchart other than a terminal location. In a perfect world, you will have two terminal blocks, one to start, and one to end. Although in reality, you’ll often see more than one stop terminal block.
Flow Lines
Flow Lines point us to the next block that will execute. While you often see them point down, they may point to the side for a loop/decision or because you run out of space.
Typically, flow lines are straight at 90 degree increments, and will have a turn in them if they need to move in a different direction.
Input/Output
This block is used to let people know that you are getting input, from a user, file, or other source, or sending output (screen, file, etc).
It does not matter what the input or output is, the same block is used. Some flowchart systems will have a separate type for files, but this is not always the case.
You will want to write what is being input, or output, in the block.
Decision Block
This is used to determine a decision. A yes/no question needs to be stated, with yes going one way, and no going another. In some flow charting systems, yes always goes to the right, while no, “falls through” going down. But this isn’t a hard fast rule.
To make it easier to read however, labels letting the reader know which is yes and no should always be used. Likewise, keeping where the yes/no flow lines move consistent will make reading the flowchart easier.
Processing Block
When ever a calculation needs to be made, a processing block will be used. Often the block will be big enough to write in what process is being done, or calculated.
Each step will be written in a new processing block.
Predefined Procedure Block
If you have several steps that need to be done, you might have want to use a predefined calculation block.
If you have programming experience, this is the idea behind a function call. The function makes it easier for repeatably in working the the code.
This series of predefined procedures will need to be found else where, so the logic and flow can be kept with. The predefined name will need to be written inside the box.
Flowcharts was originally found on Access 2 Learn
