Draw a flowchart with LaTeX

Question

I know it is not good to ask this question. But I am out of time and idea how should I start? My supervisor ask me to use LaTeX than document for this figure below which I had draw in .doc file.

Answer 1

A short code with pstricks:

\documentclass[pdf, svgnames]{article}
\usepackage{pstricks-add}
\usepackage{eqparbox}

\begin{document}

\begin{pspicture}
\sffamily
\psset{framearc=0.3,framesep=5pt}
\begin{psmatrix}[colsep=-0.75, rowsep=0.25]
\psDefBoxNodes{SA}{\psframebox{\eqparbox{FC}{Sample \\Acquisition}}}\\
   & \psDefBoxNodes{SC}{\psframebox{\eqparbox{FC}{Sample \\Checking}}} \\
    & & \psDefBoxNodes{DSC}{\psframebox{\eqparbox{FC}{Dimensionality\\ Sample Check}}} \\
    & & &\psDefBoxNodes{SST}{\psframebox{ \eqparbox{FC}{Sample Synthesis \\Techniques}}} \\
\end{psmatrix}
\psset{linecolor=Silver, doubleline, doublesep=0.35, doublecolor=Silver, arrows=->, arrowlength=0.8, arrowsize=0.6, arrowinset=0}
\foreach \s/\t in{SA/SC, SC/DSC, DSC/SST}{\ncangle[offsetA =0.8, angleA=-90, angleB=180]{\s:bl}{\t:Cl}}
\end{pspicture}

\end{document}

Answer 2

Pure TikZ picture, simplified version of your image:

\documentclass[12pt,a4paper]{memoir}
\usepackage{tikz}
\usetikzlibrary{arrows.meta,
                chains,
                positioning}

\begin{document}
    \begin{tikzpicture}[
node distance = -1mm and -1mm,
  start chain = A going below right,
   arr/.style = {-{Triangle[length=4mm,width=6mm]}, 
                 line width=4mm, gray!75},
   box/.style = {draw, rounded corners=3mm, semithick,
                 text width=28mm, minimum height=16mm,
                 inner xsep=3mm,
                 font=\sffamily, align=flush left, on chain=A},
                        ]         

% nodes in chaon
\node[box] {Sample Acquisition}; % A-1
\node[box] {Sample Checking};
\node[box] {Dimensionality Sample Check};
\node[box] {Sample\\ Synthesis\\ Techniques};
%
\draw[arr] (A-1) |- (A-2);
\draw[arr] (A-2) |- (A-3);
\draw[arr] (A-3) |- (A-4);
    \end{tikzpicture}
\end{document}

or as little bit more complex picture's code, with out-lined arrows drawn as small pictures pic:

\documentclass[12pt,a4paper]{memoir}
\usepackage{tikz}
\usetikzlibrary{arrows.meta,
                chains,
                positioning}

\begin{document}
    \begin{tikzpicture}[
node distance = -1mm and -1mm,
  start chain = A going below right,
   arr/.style = {-{Triangle[length=4mm,width=6mm]}, 
                 line width=4mm, gray!75},
   box/.style = {draw, rounded corners=3mm, semithick,
                 text width=28mm, minimum height=16mm,
                 inner xsep=3mm,
                 font=\sffamily, align=flush left, on chain=A},
     ARR/.pic = {\draw[semithick, fill=gray!40] 
                 (0,0) |- ++ (1.0, -0.6) -- ++ (0,0.2) -- ++ (0.6,-0.4)
                       -- ++ (-0.6,-0.4) -- ++ (0,0.2) -| ++ (-1.4,1) -- cycle;}    
                        ]         

% nodes in chaon
\node[box] {Sample Acquisition}; % A-1
\node[box] {Sample Checking};
\node[box] {Dimensionality Sample Check};
\node[box] {Sample\\ Synthesis\\ Techniques};
%
\pic at (A-1.south) {ARR};
\pic at (A-2.south) {ARR};
\pic at (A-3.south) {ARR};
    \end{tikzpicture}
\end{document}