Organisations and enterprises
We view organisations as being constellations of socio-cyber-physical actors, involving humans, animals, software and machines. Organisations may (jointly) undertake an enterprise(s), where we see an enterprise as being a systematic purposeful activity
The enterprise being undertaking can be of a commercial / for-profit nature, have a public / government nature, or have a not-for-profit nature. 
The structures of an enterprise may be designed to be persistent over time, or it might be foreseen as more of a temporary constellation (e.g. a project).

Service-oriented enterprises
Western countries have seen a transition from a goods-oriented economy to a services-oriented economy. Marketing sciences suggests that the notion of economic exchange, core to the economy, has shifted from following a goods-dominant logic to a service-dominant logic. While the former focuses on tangible resources to produce goods and embeds value in the transactions of goods, the latter concentrates on intangible resources and the creation of value in relation with customers. For instance, in the airline industry, jet turbine manufacturers used to follow a classical goods-dominant logic by selling turbines to airlines. However, since airlines are not interested in owning turbines, but rather in the realisation of \Stress{airtime}, manufacturers nowadays sell airtime to airlines instead of jet turbines.
Modern day enterprises are therefore increasingly service-oriented enterprises in the sense that they provide services rather than goods (alone), where the services may indeed be involve goods, e.g. "car as a service".

IT-reliant enterprises
Modern day information technology (IT) is generally seen as a key enabler of the service economy. Most, if not all, services delivered in the service economy are IT-reliant. Meanwhile, it is also clear from examples such as Amazon, AirBnB, Uber, Netflix, Spotify, Bitcoin, etc., how IT-based service innovations increasingly result in disruptive innovations of traditional sectors. The CEO of a major bank, such as ING, can even be quoted as stating "We want to be a tech company with a banking license".
As a result, it is safe to say that organisations, and their enterprises, are increasingly IT-reliant.

The critical role of models for the development, regulation, and operation of enterprises
The developmentregulation and operation of enterprises requires a strong coordination, and collaborative decision-making, among all actors / stakeholders involved. In doing so, the actors typically use models to express different aspects about the enterprise, covering at least the entire so-called "Business-to-IT stack", while addressing different concerns, such as security, privacy, agility, interoperability.

Models are well-known as a means to effectively deal with complexity in the design of systems in general, supporting transparency and a systemic perspective in decision-making, etc. As such, models enables a.o. (1) the analyses of the current, or future, affairs of the enterprise and its environment, (2) a collaborative evaluation of the impact of design decisions or new regulations, (3) the formulation of guidelines / regulations / requirements to which the enterprise should comply to, or (4) to capture guidelines / regulations to be used by actors in the enterprise. 

It is important to realise that in engineering, and computer science in particular, one has developed the implicit assumption that models are artefacts with a highly controlled structure (syntax) and mathematically defined semantics. There are, however, more, many more, forms of models in use, including informal sketches, textual descriptions, regulatory / legal texts, strategy documents, etc. One can even go as far as saying that modelling occurs naturally, when people use explicit artefacts (texts, diagrams, sketches, formal descriptions, etc.) that stand model for some observed / normative / desired aspect of a part of reality of an enterprise and its environment. 

Enterprise engineering
"[T]he creative application of scientific principles to design or develop structures, machines, apparatus, or manufacturing processes, or works utilizing them singly or in combination; or to construct or operate the same with full cognizance of their design; or to forecast their behavior under specific operating conditions; all as respects an intended function, economics of operation and safety to life and property."
In line with this general definition, we define enterprise engineering as the general term for an engineering based approach to design or evolve enterprises:
The creative application of scientific-principles to design or develop enterprises, or parts / aspects thereof; or to construct or operate the same with full cognisance of their design; or to forecast their behaviour under specific operating conditions; all as respects an intended function, economics of operation and safety to life and property.

In this vein, the EE Network focuses on model-enabled development, regulation, and operation of enterprises. In doing so, we also do not claim that enterprises, and organisations in particular, are purely engineered. Culture, politics, and human behaviour in general, have a strong influence on the way organisations, and their enterprises, actually take shape. The researchers of the EE Network, aim to support the underlying decision-making processes by enabling them through model-enabled decision making. At the same time, we acknowledge the fact that in real-life such design decisions are not always made in accordance with the information available.