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The Coherent Business to SCS Model

3 min read

At first glance the self-contained system (SCS) approach [1] is a native software architecture topic. However, there is a tight correlation to the organisational resp. the business part of the story. Here's the hook: "Each SCS is owned by one team." [2]. Further: "The manageable domain specific scope enables the development, operation and maintenance of an SCS by a single team." [3]

What's the consequence? Let's change perspective and have a view from the business side. A plausible correlation between an SCS architecture and the business layer is constituted by a mapping from the core business processes to their enabling (or maybe just facilitating) software systems. The mapping is as follows:

  1. Identify a value creating business process P.
  2. Divide P into logical steps P1 - Px whereby "logical" means that each step represents disjoint, well-defined business logic.
  3. A step is casted to a business domain or - for short - domain.
  4. Finally, each domain is mapped to a self-contained system. Shared business objects such as customer or order are exchanged via RESTful HTTP or leightweight messaging as defined in the SCS approach.

The Coherent Business to SCS Model

The mapping of the business part to its technical counterpart is coherent. Therefore, this is called the "Coherent Business to SCS Model" (CBSM).

A product organization has product managers who manage their domain products powered by SCSs. There's a good chance that they do it the agile way having teams who develop, operate and maintain their SCSs.

On the business layer the domains are tied together by the company vision which enables the product managers deriving their product vision.

The core value of the CBSM is that it enables the domains to develop with maximum speed due to minimum dependencies on system level. To be precise, the only dependency is the API. If a domain does not change its API there will be (theoretically) no limit of development within this domain. This even allows replacement of the underlying SCS once it is at the end of its lifecycle. Equivalent leightweight communication on the business layer makes this a success story.

A congruent approach has been implemented at GALERIA Kaufhof (a member of Hudson's Bay Company) [4]. It further shows an evolution of the model: A domain may be powered by more than one SCS for technical reasons.

Well, I think this kind of interaction of business and technology is not really a new idea. Have a look at The Open Group's definition of a service in SOA which embraces some of the core ideas [5]. My argument is that the Coherent Business to SCS Model is a more leightweight approach (buzzword!). I just wonder if SCS is a consequence or the driver?

[4] (in german)