Financial Case (internal) for Interoperability
The core issue around interoperability
Cost of Integration
New delivery models
Market Case (external) for Interoperability
An aspect of most all systems is the level of homogeneity versus heterogeneity. To what extend does the system run contiguously from one part or component of the system to another is very much a function of how that system components are constructed and how it worked within its own system domain of control and any other systems or subsystems and domains that it may interact with directly or indirectly. These aspects are reflected in the topic of interoperability:
The measure of how specific operations are made by and across the system. The level of contiguity is how well the system and its components may be easily associated with each other to perform part or all of the system operation.
The definitions of Contiguity in Wikipedia is - A contiguity is a continuous mass, or a series of things in contact or proximity. In a different meaning, contiguity is the state of being contiguous. The concept was first set out in the Law of Contiguity, one of Aristotle's Laws of Association, which states that things which occur in proximity to each other in time or space are readily associated.
N space Assurance
Abstraction and encapsulation