/**
* Reorder point
*/
public function getReorderPointAttribute()
{
$result = $this->average_daily_demand * $this->average_lead_time + Services::normSInv(0.95) * sqrt($this->average_lead_time * pow($this->sd_daily_demand, 2) + pow($this->average_daily_demand, 2) * pow($this->sd_lead_time, 2));
return ceil($result);
}
