I am trying to make the diagram of the popular CRISP-DM model. My code is below.
\documentclass[tikz,border=20pt]{standalone}
\usepackage{graphicx}
\usepackage{amsmath}
\usepackage{amsthm}
\usepackage{tikz}
\usetikzlibrary{chains, shapes.multipart}
\usetikzlibrary{shapes, calc, decorations.markings}
\usetikzlibrary{automata, positioning, fit, shapes.geometric}
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%% https://tex.stackexchange.com/a/442994/233668
\makeatletter
\tikzset{
database/.style={
path picture={
\draw (0, 1.5\database@segmentheight) circle [x radius=\database@radius,y radius=\database@aspectratio\database@radius];
\draw (-\database@radius, 0.5\database@segmentheight) arc [start angle=180,end angle=360,x radius=\database@radius, y radius=\database@aspectratio\database@radius];
\draw (-\database@radius,-0.5\database@segmentheight) arc [start angle=180,end angle=360,x radius=\database@radius, y radius=\database@aspectratio\database@radius];
\draw (-\database@radius,1.5\database@segmentheight) -- ++(0,-3\database@segmentheight) arc [start angle=180,end angle=360,x radius=\database@radius, y radius=\database@aspectratio\database@radius] -- ++(0,3\database@segmentheight);
},
minimum width=2\database@radius + \pgflinewidth,
minimum height=3\database@segmentheight + 2\database@aspectratio\database@radius + \pgflinewidth,
},
database segment height/.store in=\database@segmentheight,
database radius/.store in=\database@radius,
database aspect ratio/.store in=\database@aspectratio,
database segment height=0.1cm,
database radius=0.25cm,
database aspect ratio=0.35,
}
\makeatother
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
\begin{document}
\begin{tikzpicture}[start chain=going right,>=latex,node distance=0pt]
\node[draw, rectangle, align=center, rounded corners=2mm, minimum width=3cm, minimum height=1cm] (v1) {Business \understanding};
\node[yshift=0.2cm] at (v1.east) (A1) {};
\node[yshift=-0.2cm] at (v1.east) (A2) {};
\node[draw, rectangle, align=center, rounded corners=2mm, minimum width=3cm, minimum height=1cm] (v2) [right=2cm of v1] {Data \understanding};
\node[yshift=0.2cm] at (v2.west) (B1){};
\node[yshift=-0.2cm] at (v2.west) (B2){};
\node[draw, rectangle, align=center, rounded corners=2mm, minimum width=3cm, minimum height=1cm] (v3) [below right=1.5cm and -0.5cm of v2] {Data \preparation};
\node at (v2.south) (B3) {};
\node at (v3.north) (C1) {};
\node[draw, rectangle, align=center, rounded corners=2mm, minimum width=3cm, minimum height=1cm] (v4) [below=1.5cm of v3] {Modelling};
\node[xshift=0.2cm] at (v3.south) (C2) {};
\node[xshift=0.2cm] at (v4.north) (D1) {};
\node[xshift=-0.2cm] at (v3.south) (C3) {};
\node[xshift=-0.2cm] at (v4.north) (D2) {};
\node[draw, rectangle, align=center, rounded corners=2mm, minimum width=3cm, minimum height=1cm] (v5) [below left=1.5cm and 1.5cm of v4] {Evaluation};
\node at (v4.south) (D3) {};
\node at (v5.east) (E1) {};
\node[draw, rectangle, align=center, rounded corners=2mm, minimum width=3cm, minimum height=1cm] (v6) [above left=2.5cm and 1.5cm of v5] {Evaluation};
\node at (v5.west) (E2) {};
\node at (v6.south) (F1) {};
\node[database,label=below:Data,database radius=1cm,database segment height=0.5cm] (v7) [right=1.25cm of v6] {};
\draw [-latex] (A1) --+ (B1);
\draw [-latex] (B2) --+ (A2);
\draw [-latex] (B3) --+ (C1);
\draw [-latex] (C2) --+ (D1);
\draw [-latex] (D2) --+ (C3);
\draw [-latex] (D3) to [out=-90,in=0] (E1);
\draw [-latex] (E2) to [out=180,in=-90] (F1);
\node[xshift=1.5cm] at (v1.south) (A3) {};
\node[xshift=1cm] at (v5.north) (E3) {};
\draw [-latex] (E3) to [out=75,in=-25] (A3);
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
% Sloppy hardcoded block
\draw [decoration={markings, mark=at position 1 with {\arrow[scale=10,>=stealth]{>}}}, postaction={decorate}] (3.4,3.6) -- (3.5,3.6);
\draw [decoration={markings, mark=at position 1 with {\arrow[scale=10,>=stealth]{>}}}, postaction={decorate}] (2.6,-11.12) -- (2.5,-11.12);
\draw [decoration={markings, mark=at position 1 with {\arrow[scale=10,>=stealth]{>}}}, postaction={decorate}] (10.37,-4.1) -- (10.37,-4.2);
\draw [decoration={markings, mark=at position 1 with {\arrow[scale=10,>=stealth]{>}}}, postaction={decorate}] (-4.37,-3.5) -- (-4.37,-3.4);
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
\node[circle, draw=black, decoration = {
markings,
mark = at position 0.0 with {\arrow{latex}},
mark = at position 0.25 with {\arrow{latex}},
mark = at position 0.5 with {\arrow{latex}},
mark = at position 0.75 with {\arrow{latex}},
}, postaction = decorate, very thick, fit=(v1) (v2) (v3) (v4) (v5) (v6), inner sep=0pt] {};
\end{tikzpicture}
\end{document}
The code successfuly produces a nice version of the CRISP-DM model, see here for reference. I attach the result in the image below. However, despite the success, I am not satisfied with my code. Especially, the sloppy hardcoded block where I manually add the four arrows on the circular frame. I ended up doing that because I was not able to modify the scale of the decoration marking using a simple \arrow{scale=5, latex} or similar.
Can anyone propose a solution to replace the sloppy hardcoded block or some other optimization?
