Inventory levels are calculated, cached, and synchronized between your warehouse management system (WMS) and external platforms like Shopify. Your WMS should be treated as the master source for all inventory adjustments — it's not recommended to allow external systems to adjust inventory in warehouse-managed locations, as this can cause double-counting and overselling. If inventory isn't syncing to Shopify, make sure your products are assigned to the correct Shopify location so the system knows where to stock inventory. Once products are assigned to that location, the sync should work properly.

Inventory Management User Guide

Overview

Your inventory management system tracks and calculates inventory quantities across your warehouse locations and synchronizes this data with external platforms like Shopify. The system is built on a two-layer architecture that tracks physical inventory at specific locations and aggregates that data into warehouse-level totals for reporting and decision-making.

Understanding Your Inventory Architecture

Two-Layer System

Your inventory is tracked at two distinct levels:

1. Inventory Locations (Physical Layer)

Inventory locations represent the actual physical storage points in your warehouse — bins, shelves, pallets, or any other designated storage area. Each location tracks:

• Product Variant — The specific product stored at that location

• Quantity — The physical count, always measured in individual units ("eaches")

• Units of Measure (UOM) — Optional tracking for cases, pallets, or other groupings

• Expiration Date — For perishable goods that require date tracking

• Lot Number — For batch or lot-based inventory tracking

The quantity at each location is calculated by summing all inventory log entries for that location, which means every adjustment (receipt, pick, transfer, or manual count) is recorded and traceable.

2. Inventory Levels (Aggregated Layer)

Inventory levels aggregate all physical inventory from multiple locations into a single warehouse-level total per product variant. This aggregated view is used for:

• Reporting and visibility across your entire warehouse

• Making allocation and fulfillment decisions

• Synchronizing inventory with external services like Shopify

• Triggering alerts when inventory thresholds are crossed

Inventory Level Fields and Quantities

Your system calculates and tracks multiple inventory quantities for each product variant in each warehouse. Understanding these quantities helps you make informed decisions about stock levels and fulfillment.

Key Inventory Quantities

QuantityWhat It MeansHow It's UsedAvailable QuantityInventory ready to sell or allocate to ordersUsed to determine if you can fulfill customer ordersCommitted QuantityInventory allocated to unfinished pick tasksShows inventory that's been assigned to orders but not yet pickedIncoming QuantityExpected inventory from purchase ordersHelps you plan for future stock; includes confirmed and partially-received POsReserved QuantityInventory in non-pickable warehouse locationsInventory set aside and not available for normal fulfillmentSafety Stock QuantityProtected minimum stock levelsInventory held as a buffer and not available for saleDamaged QuantityDefective or unusable inventoryManually recorded damaged goodsQuality Control QuantityInventory under inspectionManually recorded inventory awaiting quality approvalUnallocated QuantityTotal unfulfilled customer demandShows how much demand exists that hasn't been assigned to inventoryBackorder QuantityDemand that exceeds available supplyAutomatically calculated when demand is greater than available inventory

Available Quantity Formula

Your system calculates available inventory using this formula:

Available Quantity = Physical Inventory
                   + BOM Virtual Inventory
                   - Committed Inventory
                   - Safety Stock
                   - Damaged Inventory
                   - Quality Control Inventory

This means your available quantity accounts for all the ways inventory is committed, restricted, or unavailable for normal fulfillment.

Synchronizing Inventory with Shopify

Your warehouse management system is the master source for all inventory data. Shopify pulls inventory levels from your WMS and displays them on your storefront.

How Inventory Sync Works

Inventory synchronization happens automatically between your WMS and Shopify. The system calculates your inventory levels, caches them for fast access, and pushes updates to Shopify so your online inventory is always current.

Ensuring Products Sync Correctly

For inventory to sync properly to Shopify, your products must be assigned to the correct Shopify location in your system.

To set up product-to-location assignments:

1. In your WMS, select all products that should be stocked at your Shopify warehouse location

2. Add these products to your warehouse location so the system knows where to stock inventory

3. Once products are assigned to that location, the sync will work properly

Best Practices for Inventory Sync

• Treat your WMS as the master source — All inventory adjustments should be made in your warehouse management system, not in external platforms like Shopify

• Avoid adjusting inventory in external systems — Do not allow external systems to adjust inventory in warehouse-managed locations, as this can cause double-counting and overselling

• Verify product-location assignments — If inventory isn't syncing to Shopify, the first step is to confirm that your products are assigned to the correct Shopify location

• Check sync status — Once products are properly assigned to a location, monitor the sync to ensure inventory updates are flowing correctly to Shopify

How Inventory Adjustments Are Tracked

Every change to your inventory is recorded in an inventory log. These logs track:

• Change Type — The reason for the adjustment (receipt, pick, transfer, manual adjustment, cycle count, etc.)

• Source Type — The system or process that initiated the change

• Quantity Changed — The amount added or removed

• Timestamp — When the change occurred

This complete audit trail means you can trace every inventory movement and understand exactly how your quantities changed over time.

Common Adjustment Types

• Update — Generic location quantity adjustment

• Create — Initial quantity recorded when a location is first created

• Archive — Quantity zeroed out when a location is deactivated

• Manual — Manager-driven adjustment from the dashboard

• Move — Transfer of inventory between two locations

• Pick — Inventory removed as part of a pick task

• Cycle Count — Adjustment from a physical inventory count

• Accept — Quantity adjustment from receiving or acceptance

Using Your WMS as the Master Source

Your warehouse management system should be your single source of truth for all inventory data. This approach prevents data conflicts and ensures accuracy across all your sales channels.

Why WMS Should Be Master

• Single source of truth — All inventory decisions are based on one authoritative system

• Prevents double-counting — When external systems adjust inventory independently, it can create conflicts

• Prevents overselling — A master WMS ensures you never sell more inventory than you actually have

• Maintains data integrity — All adjustments flow through a single system with complete audit trails

What This Means for Your Workflow

• Make all inventory adjustments in your WMS (receipts, picks, transfers, manual counts)

• Do not adjust inventory directly in Shopify or other external platforms

• Allow your WMS to push inventory updates to external systems, not the other way around

• If you need to adjust inventory in an external system, make the change in your WMS first and let it sync

Troubleshooting Inventory Issues

Inventory Isn't Syncing to Shopify

Problem: Your WMS shows inventory, but Shopify doesn't reflect the same quantities.

Solution:

1. Check that your products are assigned to the correct Shopify location in your WMS

2. In Shopify, verify that your warehouse location is set up and active

3. Select all products that should be stocked at that location

4. Add them to your warehouse location in the system

5. Wait for the sync to complete — inventory should update within a few minutes

Inventory Quantities Don't Match

Problem: Your available quantity seems incorrect or doesn't match your physical count.

Possible Causes:

• Inventory is in non-pickable or non-sellable locations (reserved or safety stock)

• Inventory is committed to unfinished pick tasks

• Inventory is in quality control or marked as damaged

• Recent adjustments haven't been synced yet

Solution:

1. Review the breakdown of your inventory quantities (available, committed, reserved, etc.)

2. Check if inventory is in special locations or statuses

3. Verify recent inventory adjustments in your audit log

4. If using cycle counts, ensure all counts have been accepted

Double-Counting or Overselling

Problem: Your inventory appears to be counted twice or you've oversold products.

Likely Cause: External systems have adjusted inventory independently of your WMS, creating conflicts.

Solution:

1. Review your inventory audit log to identify conflicting adjustments

2. Correct the inventory in your WMS to match your physical count

3. Ensure all future adjustments are made only in your WMS

4. Verify that external systems are not configured to adjust inventory

Key Takeaways

• Your inventory is tracked at two levels: physical locations and aggregated warehouse totals

• Multiple inventory quantities (available, committed, reserved, etc.) give you a complete picture of your stock

• Your WMS is your master source — all adjustments should flow through it

• Shopify and other external platforms should pull inventory from your WMS, not push to it

• Every inventory change is logged and auditable for complete transparency

• Proper product-to-location assignments ensure accurate syncing with external platforms