The discipline of Enterprise Integration grew out of the continuous efforts in the manufacturing industry to integrate the information and material flow in the enterprise to improve quality, efficiency, responsiveness and agility of the manufacturing firm.
Numerically Controlled Machines, CAD/CAM, Flexible Manufacturing Systems, Computer Integrated Manufacturing were approaches which, with increasing complexity, embraced more and more of the enterprise activity.
The step beyond the above is enterprise integration (EI). EI is a natural extension of these efforts, but extends the areas of concern, to cover the entire business, including the human/organisational element.
It is then natural that the next generation of integration effort is aimed at any enterprise, including (but not limited to) manufacturing activities.
The central tenet of Enterprise Integration has become that an enterprise (or a group of enterprises) --- as any other complex man-made system --- can, and should be designed in a professional manner, with its own design theory and practice. This defines the area of investigation for Enterprise Integration as a discipline.