simplevisor-control: command not found

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/simplevisor-control - from package: python-simplevisor

You may install the required package with command yum install {package}

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