Gemba is the Japanese word meaning “where the work is done”. A key LEAN concept is that this is where all the value-added activities are performed. Since this is where value-added activities occur, this is where all improvement actions must take place, not in an office or boardroom.
A gemba walk is actually going to the floor to observe exactly what is being done, the particular sequence and the time it takes, and documenting to determine the source of any muda and where it occurs. This is not a casual activity like the popular management by walking around that involves being seen and talking to people but not doing detailed observations.
The gemba walk involves a disciplined scientific approach that requires time to ensure the accuracy of the observations and the validity of the data. This can be a frustrating exercise. The key is to only observe and document, not step in and help or offer suggestions. If you jump in, offer suggestions and make changes, you may not understand what the root problem is. Your help may wind up being a Band-Aid solution that needs to be completely reworked, resulting in more waste.
The gemba walk is one of the first steps in any kaizen event or improvement event. It establishes a baseline of the present state. Once complete, we are in a position to analyze the data and start the improvement process. Once the process is complete, another gemba walk is done to document the improvements and compare to the original data. This allows us to compare the before and after so we can judge how effective our improvement efforts were, and determine if we have eliminated the root cause of the problem.