Discourse Assign and whisper post are technically the right way, but if they are “too technical” for your staff you can:
- create a To-Do category (visible only for your staff) and create topics for each job to do. When a job is complete you can close the discussion.
- create a To-Do category (visible only for your staff) and create a single topic with the list of jobs to do. In this case it is useful to use the checklist plugin
- you can simply use the flag (“something else”) button, to send a notification with a personal message to your staff members
- send a PM to the staff group
There are many possibilities to choose from, depending on how much and how you want to train your staff (no one is born knowing everything).