omkdepend: command not found

Have You tried accessing the binary with the full path?

Maybe Your $PATH variable doesn't contain the default paths? echo $PATH should give something like:

[root@server ~]# echo $PATH
/usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin:/root/bin

If it's empty, You may set the PATH variable with this command

export PATH="/usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin:/root/bin"

On CentOS possible default full paths are:

/usr/bin/omkdepend - from package: omniORB-devel

You may install the required package with command yum install {package}
Error in other languages:
omkdepend: bevel nie gevind nie
omkdepend: comandă negăsită
omkdepend: comando não encontrado
omkdepend: commande introuvable
omkdepend: command not found
omkdepend: käsku ei ole
omkdepend: không tìm thấy lệnh
omkdepend: komanda nerasta
omkdepend: Kommando nicht gefunden.
omkdepend: kommandot finns inte
omkdepend: komut yok
omkdepend: nie znaleziono polecenia
omkdepend: níor aimsíodh an t-ordú
omkdepend: no se encontró la orden
omkdepend: no s'ha trobat l'ordre
omkdepend: opdracht niet gevonden
omkdepend: parancs nem található
omkdepend: perintah tidak ditemukan
omkdepend: príkaz nenájdený
omkdepend: příkaz nenalezen
omkdepend: команда не найдена
omkdepend: командата не е открита
omkdepend: 命令找不到
omkdepend: コマンドが見つかりません