Logical architecture in a convergence project

[MARC COEN]

I'm looking for explanations on the logical architecture around project creation.

I'm working on the reframing of a convergence project (about 15 JIRA SD) to migrate in something that could help me to build a common operating model for Service support and service delivery.

A common instance has been created ... but two philosophy have been taken for the moment...

• A first entity have been onboarded in the common instance through several projects. One project by process. All these projects share a common insight environment
• A second and third entities have been created with another philosophy: Each entity have its own project (all the process for one entity are in a single project). But they plan to have one instance of insgiht bu entity

I'm looking for a document on best practices on logical architectures and advices. 

Best regards