\documentclass[tikz]{standalone}

\usepackage{tikz}
\usetikzlibrary{arrows,shapes,shapes.geometric,decorations,automata,shadows}

\tikzstyle{edge}=[draw,thick,->] \tikzset{state/.style={draw, text
    centered, thick, rectangle split, rectangle split parts=2, rounded
    corners,fill=blue!10}}

\newcommand{\STATE}[2]{\makebox[5em]{\vphantom{I}{\ttfamily #1}}\nodepart{second} \makebox[4em]{\vphantom{I}{\ttfamily #2}}}


\begin{document}
\begin{tikzpicture}[scale=1.25,
  initial text={},
  initial distance=2em,
  every initial by arrow/.style={thick,*->}]
  \node [state,initial] (s0) at (0,-1) {\STATE{NOMINAL}{O = I}};
  \node [state] (s1) at (4,0) {\STATE{LOST}{O = Loss}};
  \node [state] (s2) at (4,-2) {\STATE{ERROR}{O = Err}};

  \path[edge] (s0) edge[bend left] node[below, yshift=-10pt]
  {{\ttfamily fail\_loss}} (s1);
  \path[edge] (s0) edge[bend right] node[right, yshift=5pt] {{\ttfamily fail\_err}} (s2);
  \path[edge] (s2) edge node[right] {{\ttfamily fail\_loss}} (s1);
\end{tikzpicture}
\end{document}

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