Johari Window is a wonderful personal effectiveness improvement tool. Since most of the businesses today are people oriented, this can be a very useful guide for business effectiveness improvement as well.
Core Questions circle around the Blind Spot and Unknown windows! How do you know what you don’t know?
A good open feedback system will definitely improve around finding and fixing blind spots. But the unknown quadrant is not as straight forward…One of the solutions to this is in the form of being attentive to serious anomalies in behavior and creating a mechanism to spot and address these proactively…
Small problems often precede catastrophes. In fact, most large-scale failures result from a series of small errors and failures, rather than a single root cause.
These small problems often cascade to create a catastrophe. Accident investigators in fields such as commercial aviation, the military, and medicine have shown that a chain of events and errors typically leads to a particular disaster.
Thus, minor failures may signal big trouble ahead; treated appropriately, they can serve as early warning signs. Many large-scale failures have long incubation periods, meaning that managers have ample time to intervene when small problems arise, thereby avoiding a catastrophic outcome.
Yet these small problems often do not surface. They occur at the local level but remain invisible to the broader organization. Devising a mechanism for spotting and surfacing small problems before they escalate to create a catastrophic outcome is the much needed solution.
~ Roberto, Michael A. (2009-01-29). Know What You Don’t Know: How Great Leaders Prevent Problems Before They Happen. Pearson Education (US).
Great leaders do not simply know how to solve problems. They know how to find them. They can detect smoke, rather than simply trying to fight raging fires. 
To know what you don’t know, as a first step, cultivate yourself to be an Effective Problem-Finder!
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