bmfmerge: 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/bmfmerge - from package: bfast

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

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