Flowchart Symbols | What Each One Means and How to Use Them Correctly
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Category: Campaign Management
Published:
Last Updated:
Category: Campaign Management
Authors: Shusaku Yosa
You are drawing a flowchart and you stop knowing which symbol to use beyond the rectangle and the diamond. Or the symbols get used differently by different people, so every reading of the chart needs an interpretation step. Each symbol has a settled meaning, and used correctly, a chart communicates without commentary. This article covers the symbols you actually need, ordered by how often they come up, along with what each one means and where people go wrong.
Flowchart symbols are not something you pick by feel. In Japan, JIS X 0121 (symbols for information processing flowcharts, program network charts, and system resource charts) defines the shapes and how each is used. The standard corresponds to the international standard ISO 5807, and the shape libraries in Excel and PowerPoint, along with the symbol sets in drawing tools generally, follow it.
Learn the symbols once and they carry over regardless of which tool you use or who reads the chart. Conversely, use them in a way that departs from the standard and readers will snag on something somewhere.
The number of symbols you genuinely need is small. Below, the four basic symbols come first, in order of how often they appear. Get these four right and you have the foundation of a readable chart.
The symbol for the entry and exit of a flow. Draw it as a rectangle with rounded corners, or as an oval, and write either "start" and "end" inside, or the event that begins and ends the flow, such as "an order is received" or "shipping is complete."
There is always exactly one start. There can be several ends, depending on how the branches resolve. If "approved" and "sent back" finish differently, you have two end terminators.
Where people go wrong: charts that omit terminators are common, and they leave the reader unsure where to start. Even when you split a chart across pages because it will not fit on one, put a terminator at the head and foot of each page.
The most frequently used symbol, representing some piece of work or computation. Just a plain rectangle. The convention is to write it ending in a verb, as in "allocate the stock" or "calculate the total amount."
One process holds one action. If it reads like "check and register," that is a sign it should be split. Splitting it also lets you handle later changes such as moving the checking step to a different owner.
Where people go wrong: when in doubt, everything becomes a rectangle. In particular, "enter" and "output" belong in the data symbol, and "decide" belongs in a diamond. A chart drawn entirely in rectangles still works, but it carries less information.
Marks the point where a condition splits the flow. Draw it as a diamond and write the content as a question that divides the answers, such as "is there stock?" or "is the amount 100,000 yen or more?"
Always label the outgoing lines. Yes and no is fine, and where it splits three or more ways, write the conditions themselves: "under 10,000" / "10,000 to under 100,000" / "100,000 and above." An unlabeled branch leaves the reader unable to tell which path is which.
Where people go wrong: gaps in the branch conditions are the most common failure. You meant to split on "100,000 or more," but nobody decided which way exactly 100,000 goes. State explicitly whether the boundary value is included. Also, always finish drawing where each branch ends up, whether the lines eventually rejoin or each runs to its own terminator.
Not a symbol as such, but the element that most affects readability. The convention is top to bottom, left to right. As long as the flow follows that direction, it reads even without arrowheads. Whenever the flow runs against it, going bottom to top or right to left, add an arrow.
Crossing lines produce misreadings. When crossings start to accumulate, either rearrange the symbols or use the connector described below to break the line.
Beyond the basic four, the following symbols widen what you can express.
Represents input or output. A general-purpose symbol that does not specify the medium. Use it where information comes in from outside or goes out, as in "receive the application form" or "output the billing data." The difference from a process is that it represents the exchange itself rather than something being worked on internally.
Represents a paper document. Draw it as a rectangle whose lower edge is wavy. Using it where paper is clearly the medium, as in "issue the quotation" or "print the delivery note," makes the distinction from electronic data visible at a glance. A useful symbol when charting business processes.
Represents a process whose detail is defined in a separate flowchart. A rectangle with a vertical line inside each of the left and right edges. Where something like "run the credit check" itself contains multiple steps, use this symbol and split the detail into its own chart.
When a single flowchart grows too long vertically, this is the first symbol to consider. Moving the detail into a separate chart restores the overview.
Joins the flow to a separated location on the same page. Write a marker such as A or B inside a small circle and place a matching circle at the corresponding point. Use it where drawing a line would create a crossing.
When the connection spans pages, use the off-page connector, shaped roughly like a downward-pointing pentagon. Write the destination page number in that one.
Where people go wrong: a convenient symbol, but overuse makes the chart impossible to follow. Two or three pairs per page is the ceiling. Needing more than that is a sign the chart should be split.
A pair of symbols marking the beginning and end of a repeated process. Write the loop condition, such as "until all records are processed," in either the opening or the closing symbol.
You can also express repetition with a diamond and a line running back, but loop limits make it immediately clear that this section repeats. Useful when charting processes that run over many records.
Represents work a person does by hand. Used in business process charts where systematized steps and manual steps are mixed, it makes clear which parts are automated and which are not. In process improvement work, the places where this symbol clusters become the candidates for where to start.
The test is whether a separate chart exists. If it does, use predefined process; if the detail is contained in this chart, use process. The worst outcome is choosing predefined process because "writing it out would be long" and then never producing the separate chart. Readers end up hunting for a document that does not exist.
Use document when the medium is definitely paper, and data otherwise or when the medium does not matter. If you mix both in a business process chart, keep the criterion consistent across the chart. When the same invoice appears as a document in one place and as data in another, the reader will assume there is some difference and start looking for it.
A one-time conditional branch is a decision; repetition is loop limits. Drawing a diamond with a line running back is not wrong, but for processes that repeat many times, loop limits convey the structure better.
Even with the symbols used correctly, a chart becomes hard to read if the following are not observed.
For something used in an internal discussion, terminator, process, and decision alone will do the job. Strictness matters for material submitted externally, and for charts that communicate requirements for system development. Where the reader has to judge from the chart alone, the meaning of the symbols starts working as a shared language.
Yes. The shape insertion menu groups the flowchart symbols together, and the names follow the standard terminology. That said, adding a symbol means redrawing the lines each time, so it does not suit charts you update frequently. For business process charts that keep changing, a dedicated drawing tool is worth considering.
With five or more branches, a flowchart may not be the right form of expression. A decision table, which maps conditions to outcomes in a grid, often organizes the same material with fewer gaps. A flowchart suits showing a flow that proceeds in sequence; covering combinations of conditions is a job for a different tool.
At the exploratory stage, hand-drawing is preferable. Producing a clean version once the flow has settled is soon enough. Draw it in a tool from the start and the effort of revising makes you reluctant to reconsider the structure.
What a flowchart can express is the order of steps and the branches. It cannot express who does what by when, or when the whole thing finishes. Once you have drawn the business process and the sequence is settled, the remaining work is turning it into dates and owners.
Once you move past designing the execution flow of a campaign and into managing schedule against budget and results, a chart alone cannot keep up. Xtrategy manages campaign schedules alongside budget and KPIs on a single screen.
Using the symbols correctly is not an end in itself. It is the shared rule that puts a chart in a state where anyone who sees it understands it without explanation. Start by using terminator, process, and decision accurately.
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