How to Achieve in pre-built Anaplan Eco-System , Hierarchy into to flat list & Replacement

Hi All,
Currently the Anaplan eco-systems has multiple workspaces and multiple models[8 workspaces ~55 GB], now there is a proposed hierarchy change(as some models are quite complex and have Dependency on that flat list to create further Folded Lists for Reporting)

1. The List to be eliminated is a Flat List
2.Against that Flat list a Hierarchy Role up is required.

Questions:
1. How to implement over such huge dataset? How to analyze how much space required for Parallel development?
2.How to Integrate Budget/Forecast Data?
3. How to Achieve this with ~ 100% accuracy?

Answers

    1. Get the raw data on the hierarchy and see how many levels and new members will be added to the hierarchy list.
    2. First, identify the reason. what are the benefits you will get from folding lists?

    If you have solid reasons to make this change? Or there is a priority from business? Try to think of alternative ways of reporting. Play around with filters and have multiple grids aggregating data into multiple levels? Kindly provide more inputs and yours thoughts on the same.