Open at the Top; Open at the Bottom; and Continually (but Slowly) Evolving

Abstract

Systems of systems differ from traditional systems in that they are open at the top, open at the bottom, and continually (but slowly) evolving. "Open at the top" means that there is no pre-defined top level application.New applications may be created at any time. "Open at the bottom" means that the system primitives are defined functionally rather than concretely. This allows the implementation of these primitives to be modified as technology changes. "Continually (but slowly) evolving" means that the system's functionality is stable enough to be useful but is understood to be subject to modification. Systems with these properties tend to be environments within which other systems operate-and hence are systems of systems. It is also important to understand the larger environment within which a system of systems exists.

The FAST Platform: An Open and Semantically-Enriched Platform for Designing Multi-channel and Enterprise-Class Gadgets

“…In particular, several research activities deal with the lightweight provision of IT-enabled components [15,16] as well as their composition on the resource layer [17,18]. Coming instead from a business perspective, researchers also started to analyse the underlying structure of the resulting open mashup ecosystem [19] and derived first managerial implications for API providers.…”

Generic Business Model Types for Enterprise Mashup Intermediaries

“…Besides simple services such as news feed, weather information, maps, or stock information, business relevant services such as storage, message queuing, or payment came up in the last years. Chui et al 2009) and Mashup Ecosystem The explosive growth of these mashable components 1 and the emergence of the Enterprise Mashup paradigm (Hoyer and Fischer 2008) will have an enormous effect on intermediation. As indicated in Figure 1, existing services (rectangles) are composed to new value added applications (cycles) in an ad-hoc fashion.…”

Modelling patterns for systems of systems architectures

“…The general concepts of independence, evolution and emergence have been quite widely adopted, and variations of these properties feature in subsequent definitions of SoS (e.g., Fisher [3], Boardman & Sauser [4] and Baldwin & Sauser [5]) The latter two also emphasise the diversity typically seen between constituent systems (CSs) within an SoS and that that a CS must accept the need to adapt. Abbott [6] emphasises the changeable architectural features of an SoS, suggesting that an SoS is 'open at the top' (there is no 'top level' system, new CSs may be added continually) and 'open at the bottom' ('the lowest level of a system of systems may be changed out from under it at any time'). Cocks [7] argues that an SoS '...contains one or more systems for which significant aspects of the integration and life cycle development of the component system(s) are beyond the managerial control or influence of the larger system.'…”