Mapping the Textile Supply Chain from Yarn to Garment

The origin fields of a textile passport — spinning, fabric, dyeing and garment facilities — want a list, and most manufacturers do not have one. What exists is a scatter of supplier names across purchasing records. Mapping for the Digital Product Passport (DPP) is the work of turning those names into tiers, facilities and evidence.

This article describes mapping as a method: tier definition, facility identity, per-style collection, evidence and access tier.

Define the tiers

The same facility can sit in more than one tier: a vertically integrated mill spins, weaves and dyes under one roof. In that case the tier is a property of the process, not the facility. Why depth is hard is explained in tier-2 and tier-3 supplier transparency.

Give the facility an identity

"ABC Tekstil, Bursa" is not an identifier; the same name can point to two facilities and the same facility can go by three names. The standard options:

• GLN (GS1 Global Location Number): a 13-digit location identifier obtained through GS1; used directly in EPCIS events and ERP records.
• Open Supply Hub ID (OS ID): an open identifier derived from the facility name and address; common in brand supplier lists.
• Certificate licence number: the facility numbers of schemes such as GOTS, GRS and Oeko-Tex; scope is limited to the certificate.

Practical rule: one primary identifier per facility (GLN or OS ID), with certificate numbers as secondary fields. Decide the identifier together with the facility; if the supplier already has a GLN or OS ID, use it rather than creating a new one, otherwise the same site circulates under two identities.

Collect facility lists per style

Mapping is done per style, not per supplier, because the passport is per product and the same supplier uses different sub-suppliers for different styles.

1. List your styles and each style's bill of materials (fabric, yarn, trims). See preparing a bill of materials.
2. Record the tier-2 facility for each fabric quality (weaving/knitting, dyeing and finishing separately).
3. Ask the tier-2 supplier for the yarn supplier (tier 3) and yarn lot of each fabric batch.
4. Ask tier 3 for the fibre source (tier 4) at country level, and with a transaction certificate for certified fibre.
5. Date every record; open a new version when a supplier changes, never delete the old one.
6. Mark gaps explicitly as "unknown"; leaving a field empty confuses missing with unknown.

For the collection template and process see collecting data from suppliers; for the contractual side see DPP clauses for supplier contracts.

Evidence: documents, not statements

A supplier saying "we buy the yarn from X" is a row in the map, not evidence. Evidence is a transaction document:

• Invoice and delivery note: show the flow of material between facilities with date and quantity.
• Transaction certificate (TC): issued at every change of hands in schemes such as GRS, RCS and GOTS; the only valid proof of a certified-content claim. See proving recycled fibre.
• Batch/lot record: the match between a fabric batch and a yarn lot.
• Chemical declaration and test report: per lot for the dyehouse. See chemical management in textiles.

Mass balance is a simple consistency check: the fabric quantity you bought from tier 2 must be proportional to the yarn tier 2 bought from tier 3. A mismatch means a gap in the map or a leak in certified material.

What is public, what is restricted?

The whole map does not go public. A typical split:

• Public: the country of each stage (spinning, fabric, dyeing, garment making), certificate types.
• Restricted (buyer, auditor): facility identifiers, certificate numbers, batch matches.
• Authority (market surveillance): transaction documents, test reports.

Your tier-2 supplier's biggest worry is having its identity exposed to your customer; the restricted tier and masking largely remove that worry. See staying transparent while protecting trade secrets and restricted data tiers.

For what the map looks like in a multi-stage product such as denim, see DPP for denim and jeans manufacturing; for the wider framework, the textile DPP guide.

Frequently asked questions