Last update: August 2024

This document is WORLDLY CONFIDENTIAL. WORLDLY employees may share the link to this document directly with external parties. 

Purpose

The purpose of this document is to describe the methodology of the Worldly Product Impact Calculator (PIC). 

Product Impact Calculator Overview

The Product Impact Calculator methodology is built on materials and product data from industry aligned databases, including the Higg MSI and Higg Product Module. The methodology is aligned with the Greenhouse Gas Protocol Technical Guidance for Calculating Scope 3 Emissions and has been independently validated in accordance with ISO 14064-3.

Default product impact models are provided across 38 product categories, which can be further customized based on how much information is known about the product, allowing the user to move from the average-data method to the hybrid method, where it is relevant and material. Impacts per product are connected to purchase orders to calculate overall quantity of CO2e emissions (carbon dioxide equivalents). The Life Cycle Impact Assessment (LCIA) method used is IPCC AR6 GWP 100, the latest emission factor guidance delivered by IPCC.

The Product Impact Calculator includes Scope 3:

• Category 1 - Purchased Goods, which includes production of Materials, Packaging, Components, and Final Assembly impacts
• Category 4 - Upstream Transportation and Distribution 
• Category 9 - Downstream Transportation and Distribution 
• Category 11 - Use of Sold Products 
• Category 12 - End of Life  (Product and Packaging)

The basic version of our model uses the average-data method for calculating Scope 3, Category 1 as described in the Scope 3 Calculation Guidance.¹ Within the tool, we also give users the ability to move to a blended approach that substitutes generic data for primary data (moving them to the hybrid data method) for the Scope 3 Category 1 inputs that are described in detail below. 

The Product Impact Calculator includes 230 default product impact models across 38 product categories (see Appendix A). These default product impact models are built from a library of 33 industry average materials, 28 components, and 27 packaging options that is available for all tool users. Users can also select the product category “other” to model product impacts outside of the category options in the tool.  Users have the option to expand their libraries by linking data from the Higg Materials Sustainability Index (MSI) and Product Module (PM). As will be described below, the Worldly team used the best available data to model these materials and products.  

To go from product-level impacts to Scope 3 outputs, tool users connect products to Purchase Orders (POs) and dates. The linking of products, POs, and dates, enables us to allocate the emissions.

The equation is:

Total Impacts_time = ∑ (Product Impacts_product * Units_product)

Every subsequent section of this methodology is focused on the product level, as product-level impacts are aggregated to arrive at the overall tool outputs. Impacts are calculated for a product every time a user adds a purchase order to a product in the Product Impact Calculator. Keeping impacts at the product-purchase order level improves the accuracy of our model outputs because: 1) some brands manufacture a SKU in multiple facilities that change across POs; and 2) the higher resolution data available from the Worldly Facility Data Manager (FDM) will be able to more closely connect when the PO is created to the impacts from a facility. 

The Foundational Materials, Component, and Packaging Options

The key inputs to the default product impact models are the materials and components used in the 38 generic products. To build these products, we developed a collection of 33 generic materials, 28 components, and 27 packaging options. All 88 of these were modeled in the Higg Material Sustainability Index (MSI) with LCA for Experts (formally known as GaBi) serving as the background LCA database (Professional database and extension databases). The MSI methodology is publicly available.²

Materials

The set of materials included in the library was based on Textile Exchange’s Preferred Fiber & Materials Market Report (PFMMR)³ and the Roadmap to Net Zero: Delivering Science-Based Targets in the Apparel Sector⁴ working paper from the World Resources Institute and Apparel Impact Institute. The Higg MSI was used to model all three types of representative materials:

• Custom materials - that represent industry averages as defined in the Roadmap to Net Zero: Delivering Science-Based Targets in the Apparel Sector⁵ working paper;
• Example materials - from the Higg MSI (with an additional heat setting step added); and
• Blended materials - based on the expertise and insights of the Worldly team.

Overall, the list also includes non-fiber materials relevant to apparel companies (e.g. aluminum, leather, brass). We arrived at the following materials set:

The materials are meant to reflect an industry average of textile processes. At times, this means that the representative materials are a mix of yarn and textile formation methods that may never be used in the same material in the real world. Because the tool uses representative blends, the impacts for these materials will not exactly match the materials used by brands. Rather, by providing an industry-weighted average, the Product Impact Calculator provides users with a directionally correct starting point. Product Impact Calculator users are encouraged to replace these representative materials with more customized ones that they have modeled in the Higg MSI (additional details are provided in Appendix B).

The impacts for materials come from Tier 4, (Raw Material Extraction), Tier 3 (Raw Material Processing), Tier 2 (Material Production) and the transportation between those tiers of the supply chain. The inputs, assumptions, and data sources for every material is available to users within the Product Impact Calculator. 

Figure 1 - Illustration of the Product Impact Calculator material value chain

Source: Roadmap to Net Zero (World Resource Institute and Apparel Impact Institute)⁶

For each tier, the Product Impact Calculator model includes the loss rate⁷ associated with each step. The loss rate is the percentage of the input from the previous stage or step that is considered waste as part of the process. For example, a 5% loss rate means that for every 1 kg of input, there are 0.95 kg of product output (1 - 0.05 = 0.95). The impacts also include the transportation impacts for moving the material along the supply chain as well as the impacts associated with treating the waste from manufacturing. For transportation, we assume a distance of 200 km traveled by a large truck between each tier of the material supply chain. For transportation from the finalization of the material (Tier 2) to the Manufacturing and Final Assembly (Tier 1), we model a 500 km truck trip; the relevant portion of carbon emissions from this trip are allocated to the material life cycle stage. All default transportation values are taken from the Higg Index Product Module methodology⁸ (see Appendix C for additional transportation modeling specifics). A few examples will help bring this process into focus. Users can use the product library defaults or if more details are available (like specific manufacturing processes) they can alter the defaults to better match their product.

Users can use the default product impact models or, if more details are available (like specific manufacturing processes), they can create custom materials in MSI which will automatically be made available in the Product Impact Calculator. Here are the details on how two of the materials options were modeled.   

Conventional Cotton

To arrive at the conventional cotton in the materials library, we applied the yarn and textile formation estimates provided in Roadmap to Zero⁹(yarn: 75% ring spun, 25% open ended; textile: 40% knit, 60% woven). To arrive at this mix, four materials were modeled and amalgamated in the Higg MSI:

Industry-standard loss rates were applied (available in Roadmap to Zero¹⁰) to model the impact of the amalgamated material.

Denim

The inputs for the Product Impact Calculator’s denim were based on the expertise and experience of the Worldly sustainability science team. While there are many ways to manufacture denim, the following is meant to represent an industry average. The stages and processes included are:

Components

The Product Impact Calculator includes 28 default components from the Higg MSI. Within the PIC, the number of components included in a product can be altered, but the weight and composition of those components cannot be changed (these customizations need to be made in the MSI tool). A default cutting efficiency of 75% and 1% defect rate ¹¹ are applied from MSI. The table below shows what types of components are available in the tool. For a full list of the 28 components, see Appendix D.

Packaging

The Product Impact Calculator includes 27 default packaging materials from the Higg MSI. The logic for components applies to packaging as well. All packaging calculations in the tool are on a per unit of product basis. A default cutting efficiency of 75% and 1% defect rate¹² are applied from MSI. Users can further customize the packaging, including materials, weights, and cutting efficiency in the MSI tool. The table below shows what types of packaging are available in the tool. For a full list of the 27 packaging options, see Appendix E.

The default packaging type is a Bag (e-commerce/shipping) without a tertiary package (e.g. outer carton). Users who want to add or change the default packaging can select from the set of 27 types of packaging that come with the Product Impact Calculator. Total packaging impacts per product are equal to the sum of all packaging impacts used per product.

The net product weight includes the weight of packaging for all transportation from the gate to product end-of-life. The weight of the packaging is removed from the overall weight when calculating impacts from product use phase. Disposal of packaging is accounted for at the product end of life stage.

Scope 3, Category 1 – Purchased Goods and Services

We start by calculating cradle-to-gate impacts for Scope 3, Category 1 Purchased Goods and Services for each product (BOM = Bill of Materials). Within the text below, we start with the equations, define the variables, and then provide more information in paragraph form. In addition, we describe the average-data method and provide examples for how users can adjust this data or replace it with primary data to increase model accuracy and move into the hybrid method.

We define Scope 3, Category 1 Purchased Goods for each product as

Purchased Goods_pack = ∑ (BOM_mat + BOM_comp + Product_pack + Final Assembly)

BOM_mat - these impacts include raw materials through material creation (i.e. the output is a finished fabric). It also includes the transport between stages, which is modeled as a 200km¹³ trip by large truck. These impact values cannot be altered in the Product Impact Calculator, but are editable by users in the MSI when creating custom materials.

For each product, the impact of the materials is the summation of the impact of each material multiplied by material weight. The material weight considers the net use (i.e. amount of material that was lost during final assembly). A default 75% net use is applied based on our understanding of the apparel industry; users can update the net use percentage to better match the efficiency of their product designs. The material weight is then prorated based on the percent of the product it represents. Additional details on the processes used to model each material in the Higg MSI using the LCA for Experts software and database¹⁴ were described in the materials section above.

BOM_comp – these refer to things beyond materials used in a product such as buttons, zippers, or labels. All Product Impact Calculator components were originally modeled within MSI and put into the Scope 3 library. Within MSI, the components were modeled to include loss rates, net use, and transportation between stages using the MSI material defaults. Default net use is 75% and the defect rate is 1%. Components are created on a unit basis and include the weight in kg for the Component. An example is a zipper-puller that is made of 0.004 kg of brass material.

The impact calculations for BOMcomp is the Component emission factor multiplied by the number of units of each component used in the product.

Product_pack includes primary packaging by default; and users can add additional primary and secondary packaging. All Product Impact Calculator packaging options were originally modeled within MSI and put into the Scope 3 library. Within MSI, the packaging was modeled to include loss rates, net use, and transportation between stages. Packaging is created on a unit basis and includes the material weight. An example is a Small Paper Bag which is made of 0.034 kg paper.

The impact calculations for Product_pack is the Packaging emission factor multiplied by the number of units of each Packaging used in the product.

Final Assembly – there are two approaches: default final assembly impacts and linked Tier 1 facility impacts. Final assembly is calculated by product for each purchase order. A product can have multiple purchase orders with different final assembly options (e.g. one purchase order can use a default assembly option, whereas a second for the product could use Facility XYZ and third purchase order could use Facility ABC).

The default final assembly finished goods manufacturing impacts (Tier 1) were calculated using a standard emission factor per kilogram of finished product that comes from the World Apparel Life Cycle Database and used in Roadmap to Net Zero report.¹⁵ This impact (1.83 kg CO2e/kg of product) uses a global electricity mix that represents the top apparel producing countries and includes electricity consumption (80 percent of the GHG impact of final assembly), thermal energy, and minor sources such as tap water. The Final Assembly includes a default transportation leg of 500km by large truck from the Tier 2 facility to the Tier 1 facility.¹⁶ The final assembly impact also includes impacts from end of life for all of the material that was lost as scrap during the process of making the final product.

In the facility linked option, users can update the final assembly impacts by connecting a product’s purchase to a specific Higg Facility Environmental Module (FEM) that has been shared with the brand. The FEM includes self-reported and optionally third-party verified total annual energy usage by energy source and reported annual production units for the facility. The linking capability allows users to replace the default Final Assembly per unit impact with primary data from the FEM where the product was manufactured. If multiple facilities are used, multiple purchase orders can be created to link to different FEMs. In 2022 and prior, facilities report their production volumes in a variety of units including piece/pair and kg. GHG emissions are normalized by dividing the facility total annual emissions by the reported annual production volume. In FEM 2023, production units are standard based on facility type; Final Product Assembly facilities report in pieces/pairs and all other facility types must report in kilograms. When linking a FEM 2023, only Final Product Assembly and/or Finished Product Processing can be linked to the Product Impact Calculator for Tier 1. The normalized GHG emissions of the facility replace the default in the calculation.

If there is no linked FEM, the default apparel assembly assumptions are used. In addition, the Worldly team is actively working on linking the data collected in the Facility Data Manager (FDM).¹⁷ The data from FDM will be compatible with the data collected in the FEM, but done on shorter time durations (e.g. monthly), which will allow for a more accurate allocation of facility emissions to each product produced. The Worldly team will also update the Tier 1 data options over time if new default product impact models with much different average Tier 1 impacts that apparel are added to the PIC.

Scope 3, Category 4 – Upstream Logistics

We define Scope 3, Category 4 Upstream Logistics as:

Upstream Transport = ∑(Ocean + Truck + Air) * (% Up Transport Unowned)

Upstream logistics incorporates the distance a product travels from the final assembly (gate) to the distribution center. We assume that every product travels across a mix of ocean (14,850 km), truck (1,000 km), and air (1,750 km) to arrive at the distribution center. These transport impacts are multiplied by the net product weight (materials, components, and packaging) to arrive at the overall per product unit transportation impact. This aggregated number is then allocated to Scope 3 based on the percentage of the transport that is included in unowned third party.  Our default assumption is that 100% of this Upstream transportation takes place in third-party transportation assets. Users can update this percent owned value for upstream logistics at the brand level. Users can also change the percentage assigned through brand-owned and third-party distribution networks at the brand level.

The transportation modality and distance blend required to get the product to the distribution centers come from a prior draft Apparel and Footwear Product Environmental Footprinting Category Rules (PEFCR) for the Apparel and Footwear industries. The transportation values modeled are:

Scope 3, Category 9 – Downstream Transportation and Logistics

The Downstream Transportation and Logistics calculation has two parts: 1) transportation from the distribution center to a retail store or e-commerce customer; and 2) the electricity and natural gas required to operate distribution centers and retail stores. We define Scope 3, Category 9 Downstream Transportation and Logistics as

Downstream Logistics = ∑ (Down_transport + Down_dc + Down_retail)

Down_transport is the per kilogram emissions from transporting the product from the distribution center to the Retail Store of e-commerce customer multiplied by the product net weight (materials, packaging, and components) in kilograms to arrive at the overall per product unit transportation impact. The default distance and modalities for retail and ecommerce transportation are 1,000 km and large truck, respectively. The Global Warming Potential is calculated per kgkm. Like with upstream transportation, a percent ownership is applied to the total impacts to avoid applying Scope 1 impacts to the Scope 3 logistics.¹⁹ Our default assumption is that 50% of this Downstream transportation takes place in third-party transportation assets. Users can update this percent owned value for downstream logistics in the tool. Retail Center to Consumer transport (i.e. consumer driving from the retail store to their home) and any transportation related to returns are excluded.

Down_dc is the impacts allocated to each unit related to the impacts of running a distribution center. They are calculated on a per product unit basis by multiplying the default electricity and natural gas usage by the default global emissions factors that is based on a global electricity mix put together by Cascale (formerly the Sustainability Apparel Coalition). The per product unit emissions from distribution center electricity (0.065 kWh per unit) and natural gas (0.215 kWh) consumption are fixed and drawn from the most recent updates to the Higg Product Module; they were initially created using data and expertise from Cascale members. A global electricity mix based on domestic consumption was used to represent the emission factors for distribution center locations. The distribution center impacts are then allocated to Scope 3 based on the percentage of the Distribution Center work that occurs in unowned third party facilities. Our default assumption is that 50% of this Distribution Center impact takes place in third-party assets. Users can update this percent owned value for the distribution center in the Product Impact Calculator.

Down_retail impacts are calculated on a per product unit basis. Impacts are calculated by multiplying the electricity used (0.75 kWh per unit) by the relevant emissions factor. A global electricity mix based on domestic consumption was used to represent the emission factors for retail locations.²⁰ The per unit emissions from retail stores is fixed and drawn from the Higg Product Module; they were initially created using data and expertise from Cascale members. All products are considered one unit; the weight or size of each product is not reflected in this default. The Retail impacts are then allocated to Scope 3 based on the percentage of the retail that occurs is unowned third party retail stores (e.g. a multi-brand retail store. Our default assumption is that 50% of this Retail takes place in third-party stores. Users can update this percent owned value for retail stores in the Product Impact Calculator.

Electricity and natural gas consumption are the two inputs to the emissions from Distribution Centers and Retail stores.²¹ The per unit impacts are:

Scope 3, Category 11 – Use of Sold Products

We define Scope 3, Category 11 Use of Sold Products as:

Product Use_Impacts= (Net Product Weight) * (Lifetime Washes) * (Washing EF)

The per unit use phase impacts are calculated by dividing the total expected number of lifetime uses (wears) by the numbers of times worn between each cleaning. This provides the total number of times that the product will be cleaned. The number of cleanings is then multiplied by the sum of the impacts of cleaning the product. These total product lifetime cleaning impacts are then multiplied by the net weight of the product, as the allocation of impacts from washing and/or drying a product is done on a weight basis. The way in which a product is cleaned is based on the product type and some products (such as footwear) do not have any associated washing and care cycles. Details are provided in the Product Care section below and Appendix F.

The product category for the default product impact models is used to determine how often the product is washed and the type of care for the default fabric. The default material for all categories is cotton except for hosiery, for which the default material is synthetic. The default approach to drying for all categories is “Line/Air Dry” and “No Ironing.” Product weight is the key driver of product care impact; it is assumed that each load of laundry includes 4 kg of apparel, with impacts being allocated based on product weights. A subset of these assumptions is provided below.

Scope 3, Category 12: End-of-Life Treatment of Sold Products

We define Scope 3, Category 12 End-of-Life (EOL) Treatment of Sold Products as:

Product EOL_impacts = (Net Product Weight) * (End of Life Emission Factor)

For each unit of a product, the end-of-life impact is calculated by multiplying the product net weight by the default final disposal impact per kg of product. The Final Disposal Impact is a blended impact for which we assume that 31.5% of products are sent to a municipal waste incineration plant, 63% are sent to a landfill, and the remaining 5.5% are recycled by consumers. As we are using the cut off approach for recycling, there is no environmental impact associated with product recycling.

Appendices

Appendix A: The 38 Product Categories

Appendix B: Full Description of Materials in the Product Impact Calculator

Appendix C: Transportation Modeling Specifics

1. See Chapter 1, Purchased Goods and Services in Technical Guidance for Calculating Scope 3 Emissions (version 1.0) (PDF)↩︎
2. Higg MSI Methodology (February, 2023) ↩︎
3. These reports can be found at the following link: Preferred Fiber and Materials Market Report 2022 ↩︎
4. The report can be found at the following link: Roadmap to Net Zero: Delivering Science-Based Targets in the Apparel Sector (PDF)↩︎
5. Available at Roadmap to Net Zero: Delivering Science-Based Targets in the Apparel Sector (PDF) ↩︎
6. Available at Roadmap to Net Zero: Delivering Science-Based Targets in the Apparel Sector (PDF)↩︎
7. The loss rate assumptions come directly from the Higg MSI. Those loss rates were determined using “values from secondary data sources, expert guidance, and industry methodology such as Textile Exchange’s Fiber Conversion Methodology.” See the MSI methodology for additional detail: Higg Product Module (PM) Methodology (PDF)↩︎
8. Methodology is available at the following Higg Product Module (PM) Methodology (PDF)↩︎
9. Available at Roadmap to Net Zero: Delivering Science-Based Targets in the Apparel Sector (PDF) ↩︎
10. Available at Roadmap to Net Zero: Delivering Science-Based Targets in the Apparel Sector (PDF)↩︎
11. Creating Customized Trims/Components and Packaging ↩︎
12. Creating Customized Trims/Components and Packaging ↩︎
13. See Production Stage assumptions. Based on industry expertise. Higg MSI Methodology (February, 2023) ↩︎
14. LCA for Experts (GaBi) ↩︎
15. The report can be found at the following link: Roadmap to Net Zero: Delivering Science-Based Targets in the Apparel Sector (PDF) ↩︎
16. See Logistics section Higg Product Module (PM) Methodology (PDF) ↩︎
17. Enabling Supply Chain Transparency: Introducing Facility Data Manager ↩︎
18. Environmental Footprint Methods - European Commission ↩︎
19. A 50% ownership is assumed and applied, though tool users have the ability to alter this assumptions ↩︎
20. See Retail section Higg Product Module (PM) Methodology (PDF) ↩︎
21. See World Power consumption | Electricity consumption | Enerdata ↩︎
22. Table 8: Product Care Scenarios. Higg Product Module (PM) Methodology (PDF) ↩︎