This inability to extricate themselves from their environment has tremendous implications on how people analyze and synthesize a system.
It requires looking at something as a model. Like all models, it is an incomplete view of reality. It is impossible to determine all the elements and relationships to form what a person perceives as a system. At best, it only approximates reality and becomes an educated guess at best.
The selection of what is important and unimportant in a system is a value judgment. To one person, an element may be important; to another, unimportant. At best, it is a tool that enables an understanding of reality. Change the original people who provide a description of a system and the chances increase that new people will describe and perceive it differently to some degree.
This behavior is due to the complexity of most systems and the desire to simplify; both involve subjectivity . Dorner says this desire to simplify is useful, but comes at a cost. He refers to the results of this desire to simplify as "supersignals." While supersignals reduce complexity, they can vary from person to person and result in "no objective measure of complexity." 
There is one way to look at the world and it is subjective . In today's world of specialization, people will likely describe a system differently, e.g., data, time, control, etc. Project managers need to be critically aware of this fact by trying to obtain a balanced perspective of a system. Dorner observes that each person's model may differ in correctness and completeness and this fact should not be overlooked. Unfortunately, people tend to forget about this insight, especially when confronted with uncertainty. 
The boundary for a system will likely be unclear, particularly when involving social phenomena. That is because the relationships can be extremely complex and may involve many intangibles. Identifying a boundary, too, is a judgment call.
The relationships among the elements of a system are as important, perhaps even more so, than the elements themselves. Relationships reflect interactions and integration among the elements based on specific conditions. Interactions and integration reflect a synthesis among all elements to satisfy goals of a system.
Due to the difficulty in developing an objective holistic perspective of a system, how can it be possible to develop anything meaningful? The answer is to involve people who subscribe to different views on how a system behaves. Ackoff agrees, noting that it is important to view problems from multiple perspectives. He calls this multiple perspective a "transdisciplinary point of view." 
It makes good sense, therefore, to involve people who hold different viewpoints to better understand phenomena. It is the only way, short of using instrumentation that can result in biasing insights because it will likely influence the phenomena being measured.
Project managers must not only identify the elements of their projects and their relationships, they should also encourage participative decision making and collaboration whenever possible to enable a better understanding of what is happening and what to do. Failure to do so can lead to assessing circumstances inaccurately and exercising poor judgment.
 Dietrich Dorner, The Logic of Failure , Perseus Books, Cambridge, MA, 1996, p. 39.
 Dietrich Dorner, The Logic of Failure , Perseus Books, Cambridge, MA, 1996, p. 42.
 Russell L. Ackoff, Systems thinking and thinking systems, Systems Dynamic Review , p. 187, Summer “Fall 1994.