\documentclass{article}
\begin{document}
\section{The PUGH schedule:}

\fbox{\begin{minipage}[t]{\textwidth}
RECOVER\_PARAMETERS\\
STARTUP\\
WRAGH\\
PARAMCHECK\\
BASEGRID
\end{minipage}}
\\
\fbox{\begin{minipage}[t]{\textwidth}
Recover? (yes/no)
\\
\fbox{\begin{minipage}[t]{0.475\textwidth}
INITIAL\\
POSTINITIAL\\
POSTSTEP
\end{minipage}}
\fbox{\begin{minipage}[t]{0.475\textwidth}
RECOVER\_VARIABLES\\
POST\_RECOVER\_VARIABLES
\end{minipage}}
\end{minipage}}
\\
\fbox{\begin{minipage}[t]{\textwidth}
CPINITIAL\\
ANALYSIS\\
OutputGH
\end{minipage}}
\\
\fbox{\begin{minipage}[t]{0.1\textwidth}
main\\
loop
\end{minipage}
\fbox{\begin{minipage}[t]{0.87\textwidth}
Advance time\\
PRESTEP\\
EVOL\\
POSTSTEP\\
CHECKPOINT\\
ANALYSIS\\
OutputGH
\end{minipage}}}
\\
\fbox{\begin{minipage}[t]{\textwidth}
TERMINATE\\
SHUTDOWN
\end{minipage}}



\newpage
\section{The Carpet schedule:}

\fbox{\begin{minipage}[t]{\textwidth}
RECOVER\_PARAMETERS\\
STARTUP\\
WRAGH\\
PARAMCHECK\\
BASEGRID
\end{minipage}}
\\
\fbox{\begin{minipage}[t]{\textwidth}
Recover? (yes/no)
\\
\fbox{\begin{minipage}[t]{0.1\textwidth}
initial\\
loop
\end{minipage}
\fbox{\begin{minipage}[t]{0.345\textwidth}
INITIAL\\
Regrid\\
POSTREGRID\\
$\longrightarrow$ Recurse\\
Restrict\\
POSTRESTRICTINITIAL\\
POSTINITIAL\\
POSTSTEP
\end{minipage}}}
\fbox{\begin{minipage}[t]{0.1\textwidth}
recover\\
loop
\end{minipage}
\fbox{\begin{minipage}[t]{0.345\textwidth}
RECOVER\_VARIABLES\\
POST\_RECOVER\_VARIABLES
$\longrightarrow$ Recurse
\end{minipage}}}
\\
\fbox{\begin{minipage}[t]{0.47\textwidth}
3 Time Level Initialisation
\end{minipage}}
\end{minipage}}
\\
\fbox{\begin{minipage}[t]{0.1\textwidth}
initial\\
loop
\end{minipage}
\fbox{\begin{minipage}[t]{0.87\textwidth}
$\longrightarrow$ Recurse\\
CPINITIAL\\
ANALYSIS\\
OutputGH
\end{minipage}}}
\\
\fbox{\begin{minipage}[t]{0.1\textwidth}
main\\
loop
\end{minipage}
\fbox{\begin{minipage}[t]{0.1\textwidth}
evol\\
loop
\end{minipage}
\fbox{\begin{minipage}[t]{0.74\textwidth}
Regrid\\
POSTREGRID\\
Advance time\\
PRESTEP\\
EVOL\\
$\longrightarrow$ Recurse\\
Restrict\\
POSTRESTRICT\\
POSTSTEP\\
CHECKPOINT\\
ANALYSIS\\
OutputGH
\end{minipage}}}}
\\
\fbox{\begin{minipage}[t]{0.1\textwidth}
shutdown\\
loop
\end{minipage}
\fbox{\begin{minipage}[t]{0.87\textwidth}
$\longrightarrow$ Recurse\\
TERMINATE
\end{minipage}}}
\\
\fbox{\begin{minipage}[t]{\textwidth}
SHUTDOWN
\end{minipage}}

\end{document}