Getting merchandising data into a new platform usually starts with a project plan. A data team scopes the sources, someone writes a specification, and weeks pass before the first number appears on a screen. Most of that time goes on describing files that already exist.
Start with the files you have
The exports your team already produces are enough to begin. Sales by week, stock by location, the product hierarchy: drop them in as they are. Nobody has to reformat a column or rebuild a report to suit the platform.
The mapping is drafted for you
Mountin reads the files and proposes how each column maps to what the platform needs. A merchandiser can see the proposal in plain terms, one value at a time, and edit any of them with a click. The draft does the tedious part and the person keeps the judgment.
You confirm it
Nothing is used until the mapping is confirmed, so the merchandiser stays the one who says what the data means. The project plan was only ever a way of getting to that confirmation.