[KPI] Customer processing cost

[SMEWebify]

Cost of customer processing = cost of customer service over a period / total number of orders over a period

[SMEWebify]

public function getAverageCostPerOrder($startDate, $endDate)
{
    $totalCost = \DB::table('order_lines')
        ->join('technical_cuts', 'order_lines.id', '=', 'technical_cuts.order_lines_id')
        ->join('orders', 'order_lines.orders_id', '=', 'orders.id')
        ->whereBetween('orders.created_at', [$startDate, $endDate])
        ->sum(\DB::raw('technical_cuts.unit_cost * order_lines.qty'));

    $totalOrders = Orders::whereBetween('created_at', [$startDate, $endDate])->count();

    return $totalOrders > 0 ? round($totalCost / $totalOrders, 2) : 0;
}