Rules for Linking Investments
This chapter explains in detail according to which rules activities may be linked to items in the investment plans. For easy understanding, we would like to start by explaining the term Path and its meaning in the context of hierarchies.

A path in a hierarchy is the direct way from the root element to a child element at the lowest level. The following image shows several paths:
The image shows two paths along the red links, both starting from Plan A, one to Tactic LA, the second to Tactic SN. Of course, any other connection between Plan A and any other tactic is also a path.
Also note that paths share their ways down the hierarchy. The following graphic shows a part of the hierarchy with three paths:
The paths share the way via Campaign Q and Program FT. This is relevant for actions you perform on Campaign Q and Program FT, since these actions affect all three paths.
Within a hierarchy, a distinction is made between ancestors and descendants. It is important to define the starting point first, in this picture it is Program FT.
The upstream activities in the path are ancestors (Plan A, Campaign Q), the downstream activities are descendants (in preceding image the three tactics).
The term Parent may be used for the first ancestor, the first descendant is a child.
Note that it is not possible to link to a budget element and that is why this area is shown in gray in the following image. The paths start at Budget 5 and then go down via the categories, sub-categories to the line items and placeholders.
The following rules apply to linking of investments:

A financial item in the investment hierarchy can only be linked to one activity in the activity hierarchy.
See the example in the following image: Sub-Category 25 is linked to Program FT and therefore cannot be linked to any other activity.
Conversely, an activity can be linked to multiple investments, even in multiple investment plans.

The following image shows a link from the Program FT activity to Sub-Category 25 in the investment hierarchy.
As a result, the following paths are linked in the hierarchies:
Program FT cannot be linked a second time within this path in the investment hierarchy.
However, it is possible to initially link Program FT to several paths:

Let us explain this rule starting from the following picture. Program FT is linked to Sub-Category 25 and Sub-Category 43.
As a result, the following paths are linked in the hierarchies:
Due to the already existing links of Program FT, Campaign Q can only be linked to ancestors of Sub-Category 25 and Sub-Category 43 in the investment hierarchy. In the picture this is Category 2:
Logically, linking Campaign Q to descendants of Sub-Category 25 and Sub-Category 43 is not possible.
And descendants can only be linked to descendants: Therefore Tactic TB can only be linked to descendants of Sub-Category 25 and Sub-Category 43 with consideration of Rule 2:
-
Sub-Category 31
-
Line Item 21
-
Line Item 47
-
Line Item 50
This could be a possible linkage:
But there is more to this Rule 3: If paths are linked, further links can only be created within the linked paths, not outside!
The following images show links in red that are not possible as the links for Program FT have been set first and thus have defined the linked paths within the investment plan:
-
Campaign Q cannot be linked to another path in the Budget 5 plan:
However, it is possible to link Campaign Q to another investment plan, see Rule 4. -
Tactic WA cannot be linked to Line Item 61:
-
Program AZ (sibling of Program FT) cannot be linked to Sub-Category 31:
So an important consequence of this rule is that you should pay special attention to the initial linking of paths in the activity and investment hierarchies. These first links determine which further links are possible within the paths.

As we have seen in rule 3, within an investment plan the first link determines which paths are connected and how further links can be placed in these paths. Rule 4 determines where you can create the possibility for further links to other investment plans. This is always the highest linked activity in the hierarchy.
In the following graphic you have this possibility at Campaign Q.
In the following linking this is Program FT, because Campaign Q is not linked.