All businesses have a degree of complexity inherent within them that needs to be managed. Business activities that are undertaken and the systems used to support them have multi-facetted interdependencies that may results in, even with a single change, cascading consequential effects to many parts of the business.
Avoiding unexpected and adverse consequences requires a level knowledge of the business that supports the capability to make good and consistent decisions.
In establishing a knowledge repository supporting the business, a considered decision needs to be made on the both the granularity of knowledge and the degree of inter-connectedness to be captured.
As granularity becomes finer the amount of information held can increase significantly. In the most extreme case, where everything is linked to everything, the complexity grows exponentially.
A knowledge repository, perhaps in the guise of an Enterprise Architecture, without forethought and supporting processes, can have such complexity that it becomes unmanageable, unmaintainable and consequently a liability rather than an asset
When designing the Enterprise Architecture it is important to understand the capabilities and resources requirements necessary to its ongoing support. When designing the underlying framework it is important to define, at least initially, the granularity that makes sense to the types of decision that are to be made. To reduce or to at least manage the complexity, rather than capturing all dependencies, capture only those that are regarded as important.
Providing the Enterprise Architecture has appropriate breadth, giving end to end visibility of key aspects of the business, key decisions can be made effectively.
It is easy to fall into the trap, when implementing an Enterprise Architecture, to want to capture everything. With an aspiration of using it as a tool to support all decisions the complexity can be so high that it becomes counter-productive instead.
The goal for an Enterprise Architecture is that it should contain enough information to be useful and to be simple enough to be used.
The drive towards simplicity should not be overshadowed by the desire for completeness.