deletions | additions       diff --git a/begin_section_Introduction_Preliminary_efforts__.tex b/begin_section_Introduction_Preliminary_efforts__.tex  index 93898df..f7d56c4 100644  --- a/begin_section_Introduction_Preliminary_efforts__.tex  +++ b/begin_section_Introduction_Preliminary_efforts__.tex 
...
\subsection{Complexity}  Complex systems have multiple parts. Human use the technical parts and interact with other humans, introducing communication. All this is in constant change over time.I stumbled upon this example on the internet. We could consider the magnets as non-human parts of the system, marbles as humans, and sticks and pieces of wood as designed control factors to keep the components in a safe range. We can see there are many ways things can go wrong and how hard it is to modify one part without unexpected results elsewhere. \marclick on the arrow to show the operation of a model of a complex system.  \subsection { Investigating and Defining Complex Systems Failure} This area has been investigated extensively and from many points of view.