Model portoflio are used a an investment guideline with specific weights per security / produtc.
This tool is used for mass rebalancing when you are dealing with discretionnary portfolio management or it can be used for advisory / hybrid when you are dealing with a proposal.
Go to My Account Portfolio / Model Portfolio to create new model.
Model portoflio can be updated with securities you previously updated into your securities product library. Make sure that those securities are recorded with an ISIN.