Business systems architecture is an object oriented modeling approach to architecture. It is based on the same principles that are used in object oriented analysis, design, and programming for software. Business systems represent real parts of the organization much in the same way objects represents real parts in software.
Business Systems Architecture is the term I use for architecture that is anchored in reality. The reality based aspect comes from anchoring behavior and information in structure. Information cannot be stored and work cannot happen unless it is realized in and by some structure. For a more in-depth discussion read the Reality Based Architecture article.
Business systems can be made up of both people systems and IT systems. The picture below is a simple PrimaryScape representation of a team (people system) that uses an IT system.
The PrimaryScape modeling notation was created to make it easier to model real business systems. With the simple representation above one can now talk about the behavior and information of the team and the IT system. The focus is not only on process, only on information, only on IT systems, or only on people. It makes it possible to describe the entire context.
Business systems architecture can be used independently and together with established architecture practices such as IT Architecture, Enterprise Architecture, Application Architecture, Business Architecture, Domain Architecture, Process Architecture, Information Architecture, or Infrastructure Architecture.
Business systems architecture can be used to model different parts of an enterprise at any level of abstraction. It can be used to model the specific problem domain for which a solution is being developed. It can be used to model a department or organizational unit. It can be used to model an IT system together with all the different teams that are involved in operating, supporting, and developing it, as well as those teams and systems using it.