The NAB trade model, which I also use as my brokerage house uses...

The NAB trade model, which I also use as my brokerage house uses the computer methodologies of the 3 investor rating houses : Morningstar - Thomson Reuters and Columbine. They use a set of algorithms based on current trading, financial and futures to give an indicative rating on all the stocks on the ASX.

Reading the fine print of Morningstar methodologies you will see this:

The Quantitative Equity Report (“Report”) is derived from data, statistics and
information within Morningstar, Inc.’s database as of the date of the Report and
is subject to change without notice. The Report is for informational purposes
only, intended for financial professionals and/or sophisticated investors
(“Users”) and should not be the sole piece of information used by such Users or
their clients in making an investment decision. While Morningstar has obtained
data, statistics and information from sources it believes to be reliable,
Morningstar does not perform an audit or seeks independent verification of any
of the data, statistics, and information it receives.​

These are simply guides based on data and statistics without confirmation of the true value of the companies analysed.

Hope that helps. DYOR & GLTAH.