How do you turn an SOP into a flowchart?

Parsing the text first

A standard operating procedure (SOP) is often written as long compound sentences. A sentence such as 'The operator opens the valve, starts the pump if pressure is low, and opens the log' contains three actions and one decision.

The rule for splitting it is simple: one action per line, preferably starting with a verb. Make decision words visible, such as 'if ... then' and 'otherwise'. Write loops with their condition and exit, for example 'repeat until pressure is below 3 bar'. Mark steps that happen at the same time with 'at the same time'.

Name the role responsible for each step, because without role names a swimlane chart cannot show who does what. Finally, replace vague phrases such as 'as needed' or 'where appropriate' with measurable conditions.

Worked example: taking a sample

Here is a hypothetical SOP: 'The operator stops the line and labels the sample container. Repeat until the temperature is below 60 °C: wait 5 minutes and measure again. Then take the sample and record the label on the log sheet.' Written one step per line, it reads:

• Operator stops the line.
• Operator labels the sample container.
• Repeat until the temperature is below 60 °C: wait 5 minutes, then measure again.
• Take the sample.
• Record the label on the log sheet.

Loop check: the first measurement is 72 °C, above 60, so the loop keeps waiting. After 5 minutes the reading is 58 °C. Because 58 is below 60, the loop ends and the sample is taken. Total waiting time: 5 minutes.

Common mistakes

The most common mistake is vague wording. A step that says 'as needed' or 'at a suitable temperature' means different things to two operators. Replace it with a measurable threshold.

The second is packing a compound sentence into one box, where 'and' or 'or' hides a decision. The third is leaving out the 'otherwise' branch, which leaves a dead end on the chart. The fourth is writing steps without role names, so it is unclear whether maintenance or production performs them.

Finally, updating the SOP without updating the chart, or the reverse, lets two sources describe the same job differently. The same checks apply when a tool or a language model does the conversion.

Follow-up questions