I was working with a customer recently which had this problem recently and we were able to propose a solution which would work for them. So if your admin creates duplicate reports for each regional and global manager and you are wresting with how to solve this, this post would provide you principles.

Cause of the problem

The primary cause of the problem is the data model in SAP and SFDC are not matched right. In SAP, there is a customer which can have multiple ship to which are shipping locations and sold to which are the primary divisions of the customers dealing with business. There is also a sales org which is the organization division which deals with customer and division which are division of your customers which deal with customers.

In SFDC world, there is just parent and child accounts and no other object structure. So to match the data between both systems, most of the organizations follow these 2 models.

Create a key on the account which is a combination of sales org, division, sold to and ship to in SFDC.
Create a custom object linking the sold to and ship to account account and have sales org and division as attributes.

Because of the data model , when sales people are assigned to multiple accounts or global account managers having multiple accounts, visibility is impacted resulted in account owners with no value and other problems.

Territory Management to rescue

To solve the problem of assigning sales people to multiple accounts, Territory management could be an effective solution.

The key principles on this solution are as follows,

Create parent territories for each sales org in SAP.
Create child division territories for each division in SAP.
Assign Regional sales manager to the parent territory to enable visibility to all accounts in his region.
Assign sales reps based on attribute of the account which could be sold to, ship to, sales org or division code or any criteria which fits your business.

By enabling Enterprise territory management, you have the following advantages.

The default my territories view can be used on views and reports for users to view their accounts.
This can scale to any level of territories and beyond.

Enable visibility for global account managers to see all accounts

Due to current state architectures listed above, global account managers of accounts are not owner of parent accounts and they are not able to see all child accounts. Most of the organizations use parent account but the owner of parent accounts tend to be integration users, dummy accounts owner or users of no value. To solve this problem, here are some guidelines.

Set parent account owner as the global account owner.
Leverage account teams on child accounts and add global account owner to the child account teams using custom code to populate automatically. This would ensure that the global account owner can see all child accounts.

Key takeaways.

Here are the top 3 key takeaways for you on solving the visibility issue.

Leverage territory management to mimic your SAP object structure to enable visibility and scalability.
Have fields on accounts to allow territory management rules to run to assign users to the right territory.
Leverage account teams to solve global account owners to view all child accounts.

I hope this post provides you the guidelines what you are looking for. Feel free to email me at buyan@eigenx.com for next steps.