08.01-MarveliasGrossman2003a.tex

\documentclass[tikz]{standalone}
\usepackage{units}
\usepackage{helvet}
\usepackage[T1]{sansmath}
\renewcommand{\familydefault}{\sfdefault}
\normalfont

\begin{document}
\begin{sansmath}
\footnotesize    
\tikzstyle{task} = [
	draw, 
	minimum height = 1.0cm,
	minimum width = 1.5cm,
	fill=yellow!0,
	rectangle,
	text centered]
	
\tikzstyle{state} = [
	draw,
	minimum height = 0.7cm,
	circle]

\begin{tikzpicture}[auto,thick,node distance = 1cm, scale=0.95]
    %\draw[step=1cm,gray,very thin] (0,0) grid (16,9);
  
  	% states
  	\draw (1,2) node [state] (A) {A};                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          
  	\draw (5,2) node [state] (hA) {hA};                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          
  	\draw (9,2) node [state] (IB) {IB};                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          
  	\draw (13,2) node [state] (B) {B};                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          

	% tasks
	\draw (3,2) node [task] (Heat) {Heat};
	\draw (7,3.5) node [task] (R1) {R1};
	\draw (7,0.5) node [task] (R2) {R2};
	\draw (11,2) node [task] (Sep) {Sep};
                                  
    % state to task arcs
    \draw [->] (A)--(Heat);
    \draw [->] (hA) --++(0,1.5) -- (R1);
    \draw [->] (hA) --++(0,-1.5)--  (R2);
    \draw [->] (IB)--(Sep);
    
	% task to state arcs
	\draw [->] (Heat) -- node[midway,above] {1 h} (hA);
	\draw [->] (R1) -- node[midway,above] {3 h} ++(2,0)--(IB);
	\draw [->] (R2) -- node[midway,above] {1 h} ++(2,0)--(IB);
	\draw [->] (Sep) -- node[midway,above] {2 h} (B);
	
\end{tikzpicture}
\end{sansmath}
\end{document}