WEIGHTED SUM

Time-weighted sum calculation where values are prorated based on duration.

Step-by-Step Setup when creating a WEIGHTED SUM-based metered feature:

1. Navigate to Features

   • Go to Product Catalog → Features
   • Click “Add Feature”

2. Basic Information

   • Name: “Reserved Storage” (or descriptive name)
   • Type: Select “Metered”

3. Event Configuration

   • Event Name: storage.reserved (must match your event data)
   • Aggregation Function: Weighted Sum
   • Aggregation Field: gb_reserved (the property to weight by time)

4. Usage Settings

   • Usage Reset: Periodic (for capacity-based billing)
   • Unit Name: GB-time (time-weighted unit)

5. Save Feature

Calculation Example

Billing Period

Period: July 31, 2025 18:30:00 UTC to August 31, 2025 18:30:00 UTC
Total period duration: 31 days = 2,678,400 seconds

Event Data

[
  {
    "event_id": "evt_001",
    "event_name": "storage.reserved",
    "external_customer_id": "customer_123",
    "timestamp": "2025-08-16T00:00:00Z",
    "properties": {
      "gb_reserved": 20
    }
  },
  {
    "event_id": "evt_002",
    "event_name": "storage.reserved",
    "external_customer_id": "customer_123",
    "timestamp": "2025-08-18T00:00:00Z",
    "properties": {
      "gb_reserved": 10
    }
  },
  {
    "event_id": "evt_003",
    "event_name": "storage.reserved",
    "external_customer_id": "customer_123",
    "timestamp": "2025-08-20T00:00:00Z",
    "properties": {
      "gb_reserved": 10
    }
  },
  {
    "event_id": "evt_004",
    "event_name": "storage.reserved",
    "external_customer_id": "customer_123",
    "timestamp": "2025-08-25T00:00:00Z",
    "properties": {
      "gb_reserved": 5
    }
  }
]

Weighted Sum Formula

weighted_value = (property_value / total_period_seconds) × seconds_from_event_to_period_end

Calculation Process

Event 1: August 16, 2025 - 20 GB

• Event timestamp: August 16, 2025 00:00:00 UTC
• Seconds until period end: August 31 18:30:00 - August 16 00:00:00 = 15 days, 18.5 hours = 1,365,300 seconds
• Weighted contribution: (20 / 2,678,400) × 1,365,300 = (20 × 1,365,300) / 2,678,400 = 27,306,000 / 2,678,400 = 10.198660714285714 GB

Event 2: August 18, 2025 - 10 GB

• Event timestamp: August 18, 2025 00:00:00 UTC
• Seconds until period end: August 31 18:30:00 - August 18 00:00:00 = 13 days, 18.5 hours = 1,197,300 seconds
• Weighted contribution: (10 / 2,678,400) × 1,197,300 = (10 × 1,197,300) / 2,678,400 = 11,973,000 / 2,678,400 = 4.470982142857143 GB

Event 3: August 20, 2025 - 10 GB

• Event timestamp: August 20, 2025 00:00:00 UTC
• Seconds until period end: August 31 18:30:00 - August 20 00:00:00 = 11 days, 18.5 hours = 1,029,300 seconds
• Weighted contribution: (10 / 2,678,400) × 1,029,300 = (10 × 1,029,300) / 2,678,400 = 10,293,000 / 2,678,400 = 3.843303571428571 GB

Event 4: August 25, 2025 - 5 GB

• Event timestamp: August 25, 2025 00:00:00 UTC
• Seconds until period end: August 31 18:30:00 - August 25 00:00:00 = 6 days, 18.5 hours = 573,300 seconds
• Weighted contribution: (5 / 2,678,400) × 573,300 = (5 × 573,300) / 2,678,400 = 2,866,500 / 2,678,400 = 1.070200892857143 GB

Total Weighted Sum

10.198660714285714 + 4.470982142857143 + 3.843303571428571 + 1.070200892857143 = 19.583147321428571 GB

Result: 19.583147321428571 GB-time

Use Cases

Reserved Capacity Billing

Perfect for: Cloud storage reservations, compute capacity, bandwidth reservations

{
  "event_name": "capacity.reserved",
  "external_customer_id": "acme_corp",
  "properties": {
    "cpu_cores": 8
  }
}

Time-Based Resource Usage

Perfect for: Database connections, server instances, license usage

{
  "event_name": "database.connection",
  "external_customer_id": "user_456",
  "properties": {
    "connection_count": 5
  }
}

Subscription Changes

Perfect for: Mid-cycle plan changes, prorated upgrades/downgrades

{
  "event_name": "plan.upgrade",
  "external_customer_id": "merchant_789",
  "properties": {
    "new_tier_level": 3
  }
}

Infrastructure Provisioning

Perfect for: VM instances, container resources, network bandwidth

{
  "event_name": "vm.provisioned",
  "external_customer_id": "customer_101",
  "properties": {
    "memory_gb": 16
  }
}

License Allocation

Perfect for: Software seats, user licenses, feature entitlements

{
  "event_name": "license.allocated",
  "external_customer_id": "enterprise_user",
  "properties": {
    "seat_count": 25
  }
}

When to Use WEIGHTED SUM

✅ Use WEIGHTED SUM when:

• Billing for reserved or allocated capacity
• Need time-proportional calculations
• Handling mid-cycle subscription changes
• Measuring sustained resource usage over time
• Events earlier in the period have more time remaining and get higher weight

Key Characteristics

• Time-weighted calculation - Events earlier in the period have higher impact
• Perfect for capacity billing - Bills based on how long resources were allocated
• Handles subscription changes - Automatically prorates usage changes
• Complex formula - More computationally intensive than other aggregations

Next Steps

• Creating a Metered Feature - Complete setup guide
• Sending Events - How to transmit WEIGHTED SUM events