\documentclass[12pt]{article}
\newsavebox{\tbox}
\begin{document}
\begin{lrbox}{\tbox}
    \begin{minipage}[c]{.65\textwidth}\raggedright
       \begin{itemize}
       \item Function
       \item Design
       \item Tooth system
       \item Tooth count
       \item Pitch and face width
       \item Quality number
       \item Gear number
       \item Gear material, core and case hardness
       \item Pinion material, core and case hardness
       \end{itemize}
    \end{minipage}
\end{lrbox}
\parbox{.65\textwidth}{
    \usebox{\tbox}
}%
\parbox{.3\textwidth}{%
    $\left.\rule{0pt}{.44\ht\tbox}\right\}$ A priori decisions\\[1ex]
    $\left.\rule{0pt}{.56\ht\tbox}\right\}$ Design variables%
}
\end{document}