PHP开发的生产产能分析功能在企业资源计划（ERP）系统中的使用

<?php
function calculate_capacity($machine_id, $days) {
  // 查询该设备的生产速度（单位：产品/小时）
  $sql = "SELECT production_speed FROM machines WHERE id = $machine_id";
  $result = mysqli_query($conn, $sql);
  $row = mysqli_fetch_assoc($result);
  $production_speed = $row['production_speed'];

  // 计算该设备在指定天数内的产能
  $capacity = $production_speed * 24 * $days;

  return $capacity;
}
?>

<?php
function generate_production_plan($start_date, $end_date) {
  $plan = array();

  // 查询所有产品的生产需求
  $sql = "SELECT product_id, quantity FROM product_demands WHERE demand_date BETWEEN $start_date AND $end_date";
  $result = mysqli_query($conn, $sql);

  while ($row = mysqli_fetch_assoc($result)) {
    $product_id = $row['product_id'];
    $quantity = $row['quantity'];

    // 查询该产品的生产设备
    $sql = "SELECT machine_id FROM product_machines WHERE product_id = $product_id";
    $result2 = mysqli_query($conn, $sql);
    $row2 = mysqli_fetch_assoc($result2);
    $machine_id = $row2['machine_id'];

    // 计算该设备在指定天数内的可用工时
    $working_hours = calculate_working_hours($machine_id, $start_date, $end_date);

    // 计算该设备在可用工时范围内的产量
    $capacity = calculate_capacity($machine_id, $working_hours);

    // 如果产能不足以满足需求，则调整需求量
    if ($capacity < $quantity) {
      $quantity = $capacity;
    }

    $plan[] = array(
      'product_id' => $product_id,
      'quantity' => $quantity,
      'machine_id' => $machine_id,
      'start_date' => $start_date,
      'end_date' => $end_date
    );
  }

  return $plan;
}
?>

<?php
function create_production_tasks($plan) {
  foreach ($plan as $item) {
    $product_id = $item['product_id'];
    $quantity = $item['quantity'];
    $machine_id = $item['machine_id'];
    $start_date = $item['start_date'];
    $end_date = $item['end_date'];

    // 创建生产任务记录
    $sql = "INSERT INTO production_tasks (product_id, quantity, machine_id, start_date, end_date) VALUES ($product_id, $quantity, $machine_id, $start_date, $end_date)";
    mysqli_query($conn, $sql);
  }
}
?>