MENTAL MODELS AND THE FIFTH DISCIPLINE

I have come to believe that systems thinking without mental models is like the DC-3’s radial air-cooled engine without wing flaps. Just as the Boeing 247’s engineers had to downsize their engine because it lacked wing flaps, systems thinking without the discipline of mental models loses much of its power. The two disciplines go naturally together because one focuses on exposing hidden assumptions and the other focuses on how to restructure assumptions to reveal causes of significant problems.

As shown at the outset of the chapter, entrenched mental models will thwart changes that could come from systems thinking. Managers must learn to reflect on their current mental models—until prevailing assumptions are brought into the open, there is no reason to expect mental models to change, and there is little purpose in systems thinking. If managers “believe” their world views are facts rather than sets of assumptions, they will not be open to challenging those world views. If they lack skills in inquiring into their and others’ ways of thinking, they will be limited in experimenting collaboratively with new ways of thinking. Moreover, if there is no established philosophy and understanding of mental models in the organization, people will misperceive the purpose of systems thinking as drawing diagrams building elaborate “models” of the world, not improving our mental models.

Systems thinking is equally important to working with mental models effectively. Contemporary research shows that most of our mental models are very often systematically flawed. They miss critical feedback relationships, misjudge time delays, and often focus on variables that are visible or salient, not necessarily high leverage. MIT’s John Sterman has shown experimentally that players in the beer game, for example, consistently misjudge the delay in receiving orders once placed. Most players either don’t see or don’t take into account in their decision making the critical reinforcing feedbacks that develop when they panic (place more orders for beer, which wipes out their supplier’s inventory, forcing them to lengthen shipping delays, which can lead to further panic). Sterman has shown similar flaws in mental models in a variety of experiments.13

Understanding these flaws can help to see where prevailing mental models will be weakest and where more than just “surfacing” managers’ mental models will be required for effective decisions.

Eventually, what will accelerate mental models as a practical management discipline will be a library of “generic structures” used throughout an organization. These “structures” will be based on systems archetypes such as those presented in Chapter 6. But, they would be suited to the particulars of a given organization—its products, market, and technologies. For example, the particular “shifting the burden,” and “limits to growth” structures for an oil company would differ from those for an insurance company, but the underlying archetypes would be the same. Such a library should be a natural by-product of practicing systems thinking within an organization.

Ultimately, the payoff from integrating systems thinking and mental models will be not only improving our mental models (what we think) but altering our ways of thinking: shifting from mental models dominated by events to mental models that recognize longer-term patterns of change and the underlying structures producing those patterns. For example, Shell’s scenarios not only made the company’s managers aware of coming changes, they helped Shell’s managers take a first step up from the world of events—seeing patterns of change.

Just as “linear thinking” dominates most mental models used for critical decisions today, the learning organizations of the future will make key decisions based on shared understandings of interrelationships and patterns of change.

10 SHARED VISION