When a continuous workflow is normally triggered, it will trigger against every matching employee - for example, in a workflow for employee birthdays to send an email to the employees' manager and there were 5 birthdays on the same day then this would trigger the workflow 5 times as these could be 5 different managers and it would be key that each manager got the email.
However, there are times when you only want the workflow to trigger once - for example, using the above example, you may want to simply send a report to HR showing everyone who has their birthday that day and having the same email 5 times would be a nuisance.
Setting up single trigger workflows
When building a continuous workflow, there is now an option called Only trigger once per day - this option will be available to existing and new workflows and, by default, will be set to No.
Using the option shown above would mean that Each Day the workflow will run and will only trigger once - using the example above this would only send the report once rather than 5 times.
NOTE: The workflow will still have to trigger against an employee so it will trigger against the first employee it finds in the database.
If you are using this option, you should ensure that you are using either send to an external email address, using mailboxes or named people rather than roles - this is because if your task was to send a report to an employees' manager then only the manager of the first employee would ever get the report. Using specific email addresses, Natural HR mailboxes or named employees means it goes to the same person every time it triggers.
Additionally, workflow email tags are unlikely to be of use as the tags will populate based on the one employee the workflow triggered against hence why this is ideal for usage when sending a report, for example.