4.1 Bar Codes, GTINs, and Product Unit Conversions

4.1 Bar Codes, GTINs, and Product Unit Conversions

Quick Answer: In Microsoft Dynamics 365 Supply Chain Management (D365 SCM), product identification and dimensional scaling rest on two core pillars: Bar code setups (which configure symbologies, mask rules, and GS1 Application Identifiers for mobile scanning) and Unit conversions (which define mathematical relationships between units of measure). Unit conversions follow a three-tier hierarchy: Standard conversions (system-wide, intra-class), Intra-class conversions (product-specific, within the same class), and Inter-class conversions (product-specific, bridging different classes like volume to mass). For items whose piece weight varies naturally, Catch weight processing enables dual-unit inventory tracking with nominal, minimum, and maximum tolerances.

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Bar Code Setup Architecture and Symbologies

Automated data collection across receiving docks and warehouse floors requires standardized barcode configurations. In D365 SCM, bar code setup definitions are configured centrally (Warehouse management > Setup > Bar codes or Organization administration > Setup > Bar codes).

1. Core Bar Code Parameters

When defining a Bar code setup, several structural parameters dictate validation and generation:

• Bar code setup: Unique alphanumeric identifier for the profile (e.g., EAN128, UPC-12, CODE39).
• Bar code type: The underlying symbology standard.
• Mask ID: Links the setup to a bar code mask to parse or format fixed prefixes, item numbers, variant codes, and check digits.
• Font name and size: Specifies typography when rendering barcodes on reports and labels.
• Minimum and Maximum length: Enforces string length validation to reject malformed scans.

2. Supported Bar Code Symbologies

3. Bar Code Masks and Mask Characters

Bar code masks (Warehouse management > Setup > Bar codes > Bar code masks) parse incoming character strings into structured transactional data:

• I (Item): Released Product item number position.
• M (Dimension / Variant): Product dimension values (Configuration, Size, Color, Style, Version).
• P (Prefix): Static company prefix.
• C (Check digit): Algorithmic check digit (e.g., Modulo 10).
• T (Type): Barcode classification type.
• Q (Quantity): Embedded transactional quantity (common in weighable catch weight retail items).
• E (Price): Embedded sales price for retail point-of-sale labels.

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Assigning Bar Codes to Released Products and Variants

Barcodes are assigned to released products (Product information management > Products > Released products > Manage inventory tab > Bar codes):

• Granularity: A released product can maintain multiple barcode records. Each unique combination of Product dimensions (Size, Color, Style, Config, Version) and Packaging Unit (Each, Box, Pallet) can hold its own distinct barcode.
• The Scanning Toggle: The Scanning checkbox dictates whether the Warehouse Management mobile app evaluates this barcode during inbound receiving, picking, cycle counting, and transfer operations. If unchecked, the barcode is preserved for document printing or retail POS, but returns an "Item not found" error on handheld scanners.
• Default Barcode: The General checkbox marks the barcode as the primary default for that item-unit combination when printing standard labels.

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Global Trade Item Numbers (GTIN) and GS1 Mobile Scanning

A Global Trade Item Number (GTIN) uniquely identifies trade items across four standard formats: GTIN-8 (small retail items), GTIN-12 (UPC-A), GTIN-13 (EAN-13), and GTIN-14 (master cartons and shipping containers).

GS1 Barcode Parsing in the Warehouse Management Mobile App

Receiving a batch-tracked, serialized product traditionally required scanning the item, scanning the batch, scanning the serial, and manually entering the expiry date. D365 SCM streamlines this via GS1 barcode parsing (Warehouse management > Setup > Barcode parsing > Barcode parsing rules). Scanning a GS1-128 or GS1 DataMatrix barcode causes the mobile app engine to parse standardized Application Identifiers (AIs):

• AI (01): GTIN (14 digits) — resolves the Released product and transactional Unit.
• AI (10): Batch / Lot number — populates the Batch tracking dimension.
• AI (21): Serial number — populates the Serial tracking dimension.
• AI (17): Expiration date (YYMMDD) — calculates batch expiration.
• AI (15): Best before date (YYMMDD) — records quality advisory dates.
• AI (310x) / AI (320x): Net weight in kilograms or pounds — populates catch weight transactions.

A single scan captures the product, packaging level, batch, expiry date, and serial number simultaneously, eliminating transcription errors and accelerating dock receiving.

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Product Unit Conversions: Three Architectural Classes

D365 SCM manages unit relationships through Unit conversions (Product information management > Setup > Units > Unit conversions or via Released product > Product tab > Unit conversions). Conversions are divided into three mutually exclusive classes:

[!IMPORTANT] Exam Distinction: Standard conversions apply globally across all items and can never bridge different unit classes. Because physical density varies by product, any conversion bridging two distinct unit classes (e.g., Volume to Mass) must be configured as an Inter-class conversion on the specific product.

Mathematical Formulas, Precision, and Rounding

Unit conversions evaluate mathematical factors through ratios to prevent rounding errors: $\text{Target Quantity} = \text{Source Quantity} \times (\text{Numerator} / \text{Denominator})$. On the unit definition (Product information management > Setup > Units > Units), Decimal precision (0 to 4 decimal places) defines allowable fractional increments. Discrete handling units (Each, Piece) require a precision of 0 to prevent fractional allocations, whereas bulk liquids and powders require 2 to 4 decimals. The Rounding rule (Nearest, Up, Down) resolves fractional remainders.

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Dual-Unit Catch Weight Processing

In food processing, agricultural commodities, and steel distribution, items have natural physical weight variations per piece. D365 SCM addresses this through Catch weight item handling (Product information management > Setup > Dimensions > Tracking dimension groups):

• Dual Units: The item tracks on-hand quantity simultaneously in an Inventory unit (discrete handling unit, e.g., Box, Each) and a Catch weight unit (weight measurement, e.g., Kg, Lb).
• Nominal Ratio: The baseline expected conversion factor (e.g., 1 Box nominal = 25 Kg).
• Tolerance Limits: Minimum and maximum weight thresholds per unit (e.g., Min = 22 kg, Max = 28 kg). The mobile app rejects inbound scans outside these boundaries.
• Invoicing Principles: Sales orders can be priced and invoiced based on either the discrete Inventory unit (e.g., $100 per Box) or the actual recorded Catch weight unit (e.g., $4.00 per actual Kilogram weighed at dispatch).

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Implementation Scenarios and Exam Traps

[!TIP] Exam Tip — Unit Sequence Group Dependency: You cannot assign a Unit Sequence Group to a released product in advanced Warehouse Management if the corresponding intra-class unit conversions (e.g., Each to Box, Box to Pallet) have not been configured first.

[!WARNING] Exam Trap — Modifying Conversions with Active Transactions: Once an item has recorded physical or financial inventory transactions (InventTrans), modifying existing unit conversions can corrupt transaction history and inventory settlements. Always close open inventory and adjust on-hand balances to zero before restructuring product conversion factors.