optimise: 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 Debian possible default full paths are:

/usr/bin/optimise - from package: yagiuda

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

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