Dependency diagrams using Tikz

I read about the rectangle split node yesterday, so this was a chance to experiment. The code is far from perfect, but a good starting point:

\documentclass[parskip]{scrartcl}
\usepackage[margin=15mm,landscape]{geometry}
\usepackage{tikz}
\usetikzlibrary{shapes.multipart, calc}

\begin{document}
\begin{tikzpicture}[my shape/.style={
rectangle split, rectangle split parts=#1, draw, anchor=center}]
\node [my shape=7, rectangle split horizontal,name=dedi, rectangle split part fill={olive!50, blue!70, olive!50, blue!70}]  at (0,0)
{PROJ\_NUM%
\nodepart{two}   PROJ\_NAME
\nodepart{three} EMP\_NUM
\nodepart{four}  EMP\_NAME
\nodepart{five}  JOB\_CLASS
\nodepart{six}   CHG\_HOUR
\nodepart{seven} HOURS};

\draw[latex-latex, very thick, red!70!black] (dedi.two north) -- ++(0,1) -| (dedi.four north);
\draw[latex-latex, very thick, red!70!black] (dedi.five north) -- ++(0,1) -| (dedi.four north);
\draw[latex-latex, very thick, red!70!black] (dedi.six north) -- ++(0,1) -| (dedi.four north);
\draw[latex-latex, very thick, red!70!black] (dedi.seven north) -- ++(0,1) -| (dedi.four north);
\draw[very thick, red!70!black]              (dedi.one north) -- ++(0,0.5) -| (dedi.three north);
\draw[-latex, very thick, red!70!black]      (dedi.one south) -- ++(0,-0.5) node[below right, text width=3cm] {\scriptsize partial dependancy} -| (dedi.two south);
\draw[-latex, very thick, red!70!black]      ($(dedi.five south) + (0.2,0)$) -- ++(0,-0.5) node[below right, text width=2cm] {\scriptsize Transitive dependancy} -| ($(dedi.six south) + (-0.2,0)$);
\draw[-latex, very thick, red!70!black] (dedi.three south) -- ++(0,-2) -| (dedi.four south);
\draw[-latex, very thick, red!70!black] (dedi.three south) -- ++(0,-2) -| (dedi.five south);
\draw[-latex, very thick, red!70!black] (dedi.three south) -- ++(0,-2) -| node[below left] {\scriptsize partial dependancies} (dedi.six south);
\draw[-latex, very thick, red!70!black] (dedi.three south) -- ++(0,-2) -| (dedi.seven south);

\end{tikzpicture}
\end{document}

Have you seen the announcement of the tikz-dependency package in comp.text.tex?

http://www.ctan.org/pkg/tikz-dependency

for fun and exercise ...

pure tikz solution:

\documentclass[tikz,margin=3mm]{standalone}
\usetikzlibrary{arrows.meta, chains, positioning, shadows}

\begin{document}
    \begin{tikzpicture}[
node distance = 7mm and 0mm,
  start chain = A going right,
   box/.style = {rectangle, draw, fill=#1,
                 minimum height=7mm, outer sep=0pt,
                 font=\bfseries\sffamily, text=white,
                 drop shadow, on chain=A},
   box/.default = black!30!blue!50,
   lbl/.style = {anchor=north, align=center, inner ysep=2pt,
                 font=\sffamily\footnotesize\linespread{0.8}\selectfont},
   arr/.style = {draw=purple, -Triangle, ultra thick},
every edge/.style = {arr}
                        ]
\node [box=olive]   {PROJ\_NUM};    % A-1
\node [box]         {PROJ\_NAME};
\node [box=olive]   {EMP\_NUM};
\node [box]         {EMP\_NAME};
\node [box]         {JOB\_CLASS};
\node [box]         {CHG\_HOUR};
\node [box]         {HOURS};        % A-7
    \coordinate[above=of A-2]   (aux1);
    \coordinate[above=of aux1]  (aux2);
    \coordinate[below=of A-2]   (aux3);
    \coordinate[below=of aux3]  (aux4);
% arrows above nodes
\draw[arr]  (A-1)   |- (aux1) -| (A-3);
\draw[arr]  (aux2) -| (A-7);
\draw       (aux2)        edge (A-2)
            (aux2 -| A-4) edge (A-4)
            (aux2 -| A-5) edge (A-5)
            (aux2 -| A-6) edge (A-6);
% arrows below nodes
\draw[arr]  (A-1) |- node[lbl,pos=0.75] {Partial\\ dependancy} (aux3) -- (A-2);
\draw[arr]  (A-3) -- (A-3 |- aux4) -| node[lbl,pos=0.25] {Partial dependancy} (A-7);
\draw       (aux4 -| A-4) edge (A-4)
            (aux4 -| A-5) edge (A-5)
            (aux4 -| A-6) edge (A-6);
\draw[arr]  ([xshift= 5mm] A-5.south) -- ([xshift= 5mm] A-5.south |- aux3) -|
        node[lbl,pos=0.25] {Transitive\\ dependancy}
            ([xshift=-5mm] A-6.south);
    \end{tikzpicture}
\end{document}