pegasus-plan: 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 Debian possible default full paths are:

/usr/bin/pegasus-plan - from package: pegasus-wms

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