$qi{m}_{\mathit{impts}}$	Forward quantity from supplier $i$ to manufacture $m$ for commodity $p$ in period $t$ under scenario $s,$
$qm{d}_{\mathit{mdpts}}$	Forward quantity from manufacture $m$ to DC $d$ for commodity $p$ in period $t$ under scenario $s,$
$qd{r}_{\mathit{drpts}}$	Forward quantity from DC $d$ to retailer $r$ for commodity $p$ in period $t$ under scenario $s,$
$qu{k}_{\mathit{ukpts}}$	Backward quantity from collection centers $u$ to repairing centers $k$ for commodity $p$ in period $t$ under scenario $s,$
$qk{e}_{\mathit{kepts}}$	Backward quantity from repairing centers $k$ to disposal centers $e$ for commodity $p$ in period $t$ under scenario $s,$
$qk{m}_{\mathit{kmpts}}$	Backward quantity from repairing centers $k$ to manufacturer $m$ for commodity $p$ in period $t$ under scenario $s,$
$qk{v}_{\mathit{kvpts}}$	Backward quantity from repairing centers $k$ to second customers $v$ for commodity $p$ in period $t$ under scenario $s,$