If we use in the enterprise architecture framework IBM Component Business Model (CBM) and A. Osterwalder's business model canvas (BMC) for describing the business and its parts in a business domainarchitecture.

The CBM can be used to describe the overall businessfunctionality and the functional decomposition of whole enterprise into businesscomponents, which can be viewed as small independent businesses. The businesscomponents in a CBM are connected through the business services that they produceand/or consume from the other business components, forming a value network.Some of those business services are produced and/or consumed by the externalparties (including the enterprise’s customers). So from that viewpoint, for everybusiness component, an external (to the given business component) party couldbe in two different role – customers/consumers of the produced services and suppliers/producersof the required services.

The A. Osterwalder’s business model canvas can be used to describethe overall business logic of how the business works for overall enterprise, and/orfor each functional sub-division down to the business components, identified inthe CBM. Business model canvas also identifies external parties in two differentroles – partners and customers. This separation is beneficial because business usuallyneeds to employ different relationship management techniques for the externalparties playing those different roles, and usually also the channels throughwhich the value is delivered to the business, and through which businessdelivers value, are different.

Above described conceptual models (together with their language)provide the modularity and encapsulation, needed to manage the inherentcomplexity of the business functionality that whole enterprise comprises. Employing thisview in business organization/operations allows us to achieve self-optimizationof the operations of whole enterprise by optimizing the operations of separate businesscomponents, and robustness by encapsulating the business components behind thewell formed service agreements.

In principle we should be able to separate and replace anybusiness component (including IT or its parts) as an independent businessentity, without changing the internal workings of that particular business componentand affecting the operations of overall value network.

So in the behavior of a business component, there should notbe any difference, whether the external (to the given business component) partyis also external to the whole enterprise or just another part of the enterprise, but thebusiness component should definitely have different behavior (down to the clearservice agreements) towards the parties to whom it delivers services andtowards the parties that deliver services to it.

To avoid confusions with the usage of word “partner” in the A. Osterwalder's business model ontology it would not be good to denote such business components,which do not directly deliver services to the enterprise’s customers, with the sameword “partners”, for both consumers of their services and suppliers of servicesthey need.

There might be political reasons for which we want that in our language enterprise’scustomers should stand out from business components that are internal to the enterprise, and because the value network inside the enterprise uses different ways tocount for the value, the word “internal customer” might not be appropriate forconsumers of internal services.

So should we then use the word “consumer” throughout the enterprise architecture models/descriptions to denote the businessservice consumers in the business models instead of word “customer”?

In case the same business component provides thesame business service to both enterprise’s customers and other business components inthe enterprise (as in many cases IT related business components do), should we treatthose as two different service consumer classes, and use different words todenote these?