System integration is one of the important stages of the life cycle of any man-made system. This is the phase where the realized ingredients combine to create a complete system. You cannot avoid integration unless you give up to get to the finished product. During the project, the integration almost always starts late and finishes very late, thus causing much delay in the project schedule. Always full of surprise, integration process is always threatening to slip into the chaos. The situation often requires the involvement of "hero" to get the project out of the quagmire.
The integration process is not just a series of tests that make progress from the parts, through intermediate system configurations up to the final product that is offered to the client. Those who see the product as a ultimate result of the integration will be surprised to discover that after they've seemingly finished the job, they are surprised that adding the users or operators opens up the whole new world of problems. And after the phase of human-machine integration is completed, unexpected surprises lurk during the system's introduction into the mix of organization's business.
There is no one right way to do integration: processes differs from one organization to another as well as organizational structures or engineering approaches utilized to perform the. The integration is more than the core of building integration environments, performing testing, reporting results and solving problems – it mixes in complex logistics, management of people and work, management of knowledge and information and even never-ending struggle for resources with project management.
Integration is also a complex social human process full of conflicts including arguments about "who must fix" and "who must pay for the fixes" – this "human issues" are the source of many problems and challenges.
Integration process is the hotbed of adaptation where the participants continuously adapt to each other and to the ebb and flow of the project, changing system configurations and even basic assumptions of the system design. The variety of engineering and management cultures, people skills and characters on the backdrop of mutual interdependence makes the integration process to exhibit characteristics of complex adaptive system (CAS) leading to unexpected behavior and large-scale crises but also to the promise of greater flexibility and robustness.
The research and practice of systems engineering offer a variety of solutions to problems of integration – model-based systems engineering, incremental development, etc. But the published papers consistently ignore the human side of the process. It is possible that to deal with complex adaptive process, we need complex adaptive Integrator that uses diverse information sources, and different types of testing, adapts modeling and reporting styles to the need of current situation, creates "social networks" of developers and users, controls the flow of information between the participants in the project and most importantly adapts to changing situations , changes attitudes, going up and down in the system hierarchy, and never but never ceases to learn.