Why do we build both flat lists and system modules in the data hub? Is Anaplan not able to import from lists? System Modules have many benefits such as improving performance or organize data (PLANS). One of which is to build Lists hierarchies. You want to store your lists in a flat manner in the Data Hub but in a way that will allow the spokes models to build or refresh their hierarchical list. You may ask why don't we store the lists in the right hierarchy in the data hub, to begin with? and an answer would be:
Hierarchical lists take more space than flat lists. We don't use hierarchical lists in the data hub so we don't need to store them there either.
If we store the hierarchical lists in the data hub and then want to build or refresh the lists in the spokes model, we won't have an option but to import from List to List (data hub - spokes). While Anaplan is technically capable of doing so, it is much slower and resource-intensive than importing from a module (saved view)
System modules are a way to store the list hierarchical information in a flat manner. Consider the System Module below Sys06 Country Details in the Data Hub
It helps us recognize the parent -Region - for every country in a flat manner. We can use this module (saved view) to create the Hierarchical List Country in the the spoke model.
2. Why did we create a hierarchical list in the data hub when we were told it's best practice not to?
I believe the training asked us to build these "try it" hierarchies just to test building a hierarchical list from a system module. You are supposed to delete them or ignore them.
3. Why the loading order matter?
Generally speaking, if you are loading 2 lists, then you can't load the child (G2 Country for example) before the parent (G1 region) because we need to reference the parent of the country when we are loading the list.
If you are loading a module dimensioned by a particular list, then you need to ensure that list exists first.
Einas "Give a Man a Fish, and You Feed Him for a Day. Teach a Man To Fish, and You Feed Him for a Lifetime"