UML2 Activity Diagram with Tikz in Latex

uml2-activity-diagram.tex

\documentclass{article}
\usepackage[utf8]{inputenc}
\usepackage{tikz} 
\usepackage[T1]{fontenc}
%\usepackage{fontspec}
% http://www.texample.net/tikz/examples/diagram-chains/
\usetikzlibrary{%
  arrows,%
  calc,
  shapes,
  arrows,
  shapes.misc,% wg. rounded rectangle
  shapes.arrows,%
  chains,%
  matrix,%
  positioning,% wg. " of "
  scopes,%
  decorations.pathmorphing,% /pgf/decoration/random steps | erste Graphik
  shadows%
}
\usepackage{amsmath}
\usepackage{relsize}
\begin{document}


\tikzset{% UML2 Activity Diagram Styles
  process/.style    = {fill=black!5,draw, thick, rounded corners=0.8em, minimum height = 3em,
    minimum width = 3em, align=center, inner sep=1em,node distance=4em},
  object/.style    = {fill=black!5,draw, thick, rectangle, minimum height = 3em,
    minimum width = 3em, align=center, inner sep=1em,node distance=4em},
  pin/.style    = {fill=black!5,draw, thick, rectangle, minimum height = 0.6em,
    minimum width = 0.6em, node distance=-1pt, inner sep=0,font=\relsize{-3.5}},
  start/.style      = {fill=black,draw,circle,node distance=4em}, 
  group/.style      = {color=black,thin,rounded corners=0.8em, rectangle}, 
  groupCaption/.style      = {above=0.2cm,right=0.2cm,fill=white}, 
  input/.style    = {coordinate,node distance=2em}, 
  output/.style   = {coordinate,node distance=2em}, 
  between/.style args={#1 and #2}{ % http://tex.stackexchange.com/a/138828/15602
    at = ($(#1)!0.5!(#2)$)
  }  
}

%\makeGroup{Title}{Top}{Left}{Width}{Height}
\newcommand{\makeGroup}[5]{
  \draw [group](#2-0.5,#3+1.5-#5)rectangle(#2+#4+0.5,#3+1.5);
  \node at (#2,#3+1.5) [groupCaption] {\textsc{#1}};
}

\begin{tikzpicture}[auto, thick, node distance=2cm, >=triangle 45]
	% Boxing and labelling 
    \makeGroup{cook spaghetti}{0}{0}{11.5}{5.0}
	\draw
      
        node at (0,0) [object](SpaghettiRaw){spaghetti\\{[raw]}}
        node [process, right=of SpaghettiRaw](AddSpaghetti){add spaghetti\\To water}
        node [pin,right=of AddSpaghetti](PinSpaghettiInWater){2}
        node [pin,left=of AddSpaghetti](PinSpaghettiRaw){}
        node [pin,below=of AddSpaghetti](PinBoilingWater){}
        
        
        node [process, right=of AddSpaghetti](CookSpaghetti){cook spaghetti\\for 10min}
        node [pin,left=of CookSpaghetti](PinSpaghettiInWater2){}
        node [pin,right=of CookSpaghetti](PinCookedSpaghetti){}
        node [pin,below=of CookSpaghetti](PinUsedWater){}
        node [pin,below=of CookSpaghetti, right=0.1em of PinUsedWater](PinExample2){}
        
        node [process, below=of AddSpaghetti](BoilWater){boil water}
        node [start, left=of BoilWater](Start){}
        
        node [object, right=of BoilWater, below=6 em of PinUsedWater](Water){<<water>>}
       
        node [object, right=of CookSpaghetti](SpaghettiAldente){spaghetti\\{[al dente]}}
        
        node [input,left=of SpaghettiRaw](Input){}
        node [output, right=of SpaghettiAldente](Output){}
        ;
     
    % Commands \draw with options like [->] must be written individually
	\draw[->](PinSpaghettiInWater) -- (PinSpaghettiInWater2);
    \draw[->](Start) -- (BoilWater);
    \draw[->](BoilWater) -- (PinBoilingWater);
    \draw[->](SpaghettiRaw) -- (PinSpaghettiRaw);
    \draw[->](PinCookedSpaghetti) -- (SpaghettiAldente);
    \draw[->](Input) -- (SpaghettiRaw);
    \draw[->](SpaghettiAldente) -- (Output);
    \draw[->](Water) |- (BoilWater);
    \draw[->](PinUsedWater) -- (Water) node (A) [pos=0.4, anchor=west] {used water};
    
     
\end{tikzpicture}

\end{document}