\documentclass[a4paper]{article}


\usepackage{pstricks}

\usepackage{pstcol} % To use the standard "color" package with PSTricks
\usepackage{pst-node}
\usepackage{pst-plot}

\usepackage{graphicx}

\pagestyle{empty}


\begin{document}

\begin{center}
  \psframebox[linearc=5mm,cornersize=absolute]{%
    \begin{psmatrix}[rowsep=.5cm,colsep=0.8cm]
      \psovalbox[fillstyle=solid,fillcolor=yellow]{Inicio} \\
      \psframebox{Inicializaci\'on} \\
      \psdiabox[fillstyle=solid,fillcolor=pink]{Especial} &
         \psframebox{Llamada a SP1} & \psframebox{Llamada a SP2} \\
      \psframebox{Acci\'on 1} \\
      \psframebox{Acci\'on 2} \\
      \psovalbox[fillstyle=solid,fillcolor=yellow]{Final}
      % Links
      \ncline{1,1}{2,1}
      \ncline{2,1}{3,1}
      \ncline{3,1}{4,1}>{\textcolor{red}{ No}}
      \ncline{4,1}{5,1}
      \ncline{5,1}{6,1}
%      \ncbar[nodesepB=10mm]{->}{1,1}{3,2}
      \ncline{->}{3,1}{3,2}^{\textcolor{red}{Si}}
      \ncline{->}{3,2}{3,3}
      \ncbar[angleA=-90,armB=0,nodesepB=2.5mm]{->}{3,3}{4,1}
      \ncdiag[angleA=-90,angleB=90,armA=0.1,armB=0.5]{->}{1,1}{3,2}
    \end{psmatrix}}
\end{center}

\end{document}
