upssched: 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/sbin/upssched - from package: nut-client

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

On Debian possible default full paths are:

/sbin/upssched - from package: nut-client

You may install the required package with command apt-get install {package}

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