[Tex/LaTex] Horizontal flow chart with several block groups

Question

I would like to draw a horizontal flow chart like one shown in the image. I have no idea how can I add additional group of blocks (or scopes?) which leading to the one element small_label. The following is my code:

\begin{tikzpicture}[node distance = 5mm and 7mm, start chain = going right, block/.style = {draw, align=center, font=\linespread{0.8}\scriptsize}, small_label/.style = {align=center, font=\linespread{0.8}\scriptsize}]
    \begin{scope}[every node/.append style={on chain, join=by -Stealth}]
        \node (n1) [block]  {A \\ 1};
        \node (n2) [block]  {A \\ 2};
        \node (n4) [small_label] {Result};
    \end{scope}

\end{tikzpicture}

Answer 1

I am a newbie but I would like to improve my skills and help the community so i tried something and probably the more experienced users would help us. I know that this is not what you asked for but maybe you can take inspiration from this:

 \documentclass{article}
 \usepackage{tikz}
 \usetikzlibrary{shapes,arrows,positioning}

 \begin{figure}[!h]
 \begin{center}
 \begin{tikzpicture}[auto,>=latex',every node/.append style={font=\scriptsize}]

    \node [input, name=input] {};
    \node [block, right=of input] (a1) {A\\1};
    \node [block, right=of a1] (a2) {A\\2};
    \node [block, below=of a2] (a3) {A\\3};
    \node [block, below=of a1] (a4) {A\\4};
    \node [block, below=of a3] (a5) {A\\5};
    \node [block, below=of a4] (a6) {A\\6};
    \node [block, below=of a5] (a7) {A\\7};
    \node [output, right=of a3] (result) {Result};

    \draw [->] (a1) -- (a2);
    \draw [->] (a1) -- (a3);
    \draw [->] (a4) -- (a5);
    \draw [->] (a6) -- (a7);
    \draw [->] (a2) -- (result) node[anchor=west] {Result};
    \draw [->] (a3) -- (result) ;
    \draw [->] (a5) -- (result) ;
    \draw [->] (a7) -- (result) ;

\end{tikzpicture}
\end{center}
\end{figure}
\end{document}