To know how to take advantage of all the functionalities of thesSupplier portal, see this article: http://help.lsp.expert/en/articles/3340222-getting-started-with-the-supplier-portal.
When a supplier finishes a job, you might want them to validate a list of items before they close the job. For example: "Did you use the translation memory?", "Did you respect the referance material provided?", "Did you run the spellcheck?", etc.
You can define all these items yourself, based on your way of working and on the job itself.
To create such a checklist, click on the outsourcing tab of the job, and then on Edit in the supplier portal panel.
In the popup that opens, click on "Add a checklist item" for every item the supplier should check before closing the job.
Now, when closing a job, the supplier will have to go through all the items you defined before they can close the job.
If you always use the same checklist with all your suppliers and all your outsourced jobs, you can define a default checklist under Settings > Document and email configuration. Select the document configuration you would like to update and click on the "Supplier portal" tab. You can then define all your checklist items.
Next time you outsource a job, your default checklist will be added automatically to the supplier portal.