The Interference Diagram Part 1

In this series of posts, I'm going to present a problem-solving tool that hasn't gotten a lot of attention.  When faced with solving a problem selecting the correct tool to solve the problem can make a world of difference.  Suppose the problem you are faced with is to figure out how to insert a nail into a specific location.  Obviously, the best tool that comes to mind is a hammer.  Suppose your problem was to figure out how best to cut a piece of wood – the immediate response is a saw.  Each of these tools is well suited to solve the existing problem.  But what if you tried to use the saw to hammer a nail?  The saw is a tool, but it’s the wrong tool to solve the problem.  Conversely, the hammer is not a good tool choice to saw a piece of wood.  It is possible that each tool, even though used incorrectly, might eventually solve the problem.  However, the results achieved and the time required would be unacceptable.  So, selection of the proper tool to solve the problem is paramount.  What if a single tool existed that could be used to solve multiple problems?  That the benefit of the tool could be applied to many different problems?  Such a tool does exist for solving business, production, manufacturing and other issues.  It’s called an Interference Diagram.

Enter the Interference Diagram (ID)

The Interference Diagram (ID) is a thinking tool that offers the ability to define those interferences, or obstacles, that block, or hinder your ability to achieve a specific goal or outcome.  It is often far easier to define what we want, and much more difficult to define why we can’t have it.  The ID can be used at many different levels to understand why things don’t happen.  It’s a tool used to verbally surface the “interferences” that stop us from achieving a specific goal or outcome.  The ID can be used as a stand alone tool, or it can be used in conjunction with other tools.  Its uses are multiple.  As a stand alone tool it can provide a discrete analysis to understand the obstacles that prevent accomplishment of the goal. In a broader application it can also be used to supplement other systems thinking tools, such as Goldratts System Thinking tools and the Five Focusing Steps.  Used as either a stand alone, or in combination with thinking tools, the end results can be dynamic.

 Concept and Structure

The concept and structure of an Interference Diagram is simple.  The figure below displays the structure.  First, in the center of a white board, or piece of paper write down what you want more of, or what your goal is.  A succinct, precise statement is always easier to work with.  Long drawn out statements that turn into paragraphs will slow down your thinking.  Avoid the tendency to write in  that fashion.  Keep it simple and to the point.

Next, when you consider what you want more of – the goal you’ve written down, think to yourself “What stops me from getting more of what I want?” The answer to this question becomes the interference that you write on the diagram.  Ask the same question again and write down your next response.  Continue to list your interferences until you are satisfied that your list is fairly complete, or at least sufficient to move on.  There is no specific number of interferences that need to be noted, you just want to surface the major interferences as to why you can’t achieve what you want more of. Don’t be shy about listing the interferences – it is important to list them all –even if they are things you know you can do nothing about.  If you use the ID to conduct an analysis where time is an important factor, then it is important to quantify your interferences with time.  In other words, how much does this particular interference take away from what you want?  Not all ID’s will require the time element, but most will.  Remember also to keep the time element constant, i.e., minutes, hours, days, or whatever measure you use. When you quantify the interference with a proper time, it will significantly increase the level of impact to determine how important the interference really is.  Without a known time all of the interferences look the same and it’s difficult to distinguish the important few from the trivial many.

In my next post, I will present an actual example of how to construct an Interference Diagram.

Bob Sproull