For a given system, the environment is the set of all objects outside the system: (1) a change in whose attributes affect the system and (2) whose at… - Arthur David Hall III

For any given system, the environment is the set of all objects whose behaviour is influenced by the behaviour of the primary system, and those objects whose behaviour influences the behavior of the primary system.

Synthesis of systems is much more difficult. Here science and engineering begin to take on aspects of art. A systems designer or planner not only must construct systems that work harmoniously individually and in tandem, he must also know a lot about the environment that the system is intended to match. Consideration of environmental factors requires foresight and experience; no one can ever foresee all the variables of importance and a choice of which to include is often a difficult one to make.

A system is a set of objects with relationships between the … in may be described generally as a complex of elements or components directly or indirectly related in a causal network, … Also, we are mainly interested in systems within which some process is continually going on, including an interchange with an environment across the boundary. It is generally agreed that when we deal with the more open system with a highly flexible structure, the distinction between the boundaries and the environment becomes a more and more arbitrary matter, dependent upon the purpose of the observer.