Update design flow image

graphics/design_flow.tex

@@ -1,25 +1,16 @@
 \documentclass{standalone}
 \usepackage{tikz}
-\usetikzlibrary {arrows.meta,graphs,graphdrawing} \usegdlibrary {layered, trees}
+\usetikzlibrary {arrows.meta,graphs,graphdrawing,positioning} \usegdlibrary {layered, trees}
 \tikzset{nodes={text height=.7em, text width=2.8cm, align=center,
 draw=black!50, thick, font=\footnotesize, fill=white},
 >={Stealth[round,sep]}, rounded corners, semithick}
 
 \begin{document}
-
-
-\begin{tikzpicture}
-    \draw[fill=lightgray] (-1.7,0.5) rectangle (5, -2.8);
-    \draw[fill=lightgray] (-1.7,-3) rectangle (5, -5.5);
-    \draw (3.4,0) node[draw=none, fill=none] (wf) {Waterfall};
-    \graph [layered layout, level distance=1.2cm, sibling sep=.5em, sibling distance=3.4cm, component order=by first specified node] {
-        pd [as=Problem Description,grow=down] -> "Specifications" -> "Initial Design" -> "Feature Separation" -> {Rapid Development ->[bend right] Variable Approach};
-        {Rapid Development <-[bend left] Variable Approach};
-        {Rapid Interation Design Method[draw=none, fill=none] ->[draw=none] Variable Approach};
-        { [same layer] Feature Separation, Rapid Interation Design Method};
-        
-        %-> tree[fill=none, minimum height=3cm, minimum width=6cm] // [tree layout] {Rapid Development -> Variable Approach};
-        { [same layer] Variable Approach, Rapid Development };
-    };
+\begin{tikzpicture}[on grid,y=1.2cm,x=3.2cm]
+    \draw[fill=lightgray] (-1.7cm , 0.5cm) rectangle (5cm, -2.8cm);
+    \draw[fill=lightgray] (-1.7cm,-3cm) rectangle (5cm, -7.2cm);
+    \input{design_flow.tikz}
+    \draw (3.4cm,0cm) node[draw=none, fill=none,text width=2.9cm] (wf) {Systems Engineering:\\Waterfall};
+    \node (ridm)[right=1 of fs, fill=none, draw=none] {Rapid Iterative Design Method};
 \end{tikzpicture}
 \end{document}

graphics/design_flow.tikz

@@ -0,0 +1,16 @@
+%&tex
+    \node (pd) {Problem Description};
+    \node (sp)[below=1 of pd]  {System\\Requirements};
+    \node (id)[below=1 of sp]  {Initial Design};
+    \node (fs)[below=1 of id]  {Feature Definition};
+    \node (ss)[below=1 of fs]  {Feature Selection};
+    \node (a1)[below=0.8 of ss,draw=none, fill=none] {};
+    \node (rd)[below=0.8 of a1]  {Rapid Development};
+    \node (va)[right=1 of a1]  {Variable Approach};
+    \path[->] (pd) edge (sp)
+              (sp) edge (id)
+              (id) edge (fs)
+              (fs) edge (ss)
+              (ss) edge (rd)
+              (rd.east) edge[bend right] (va)
+              (va) edge[bend right] (ss.east);