1 Introduction
2 Methodology
3 Developing the DFCD guideline
3.1 Literature review
Topics | Search query (TITLE-ABS-KEY) | Entries | Selected |
---|---|---|---|
CE + Product Design | (“Circular Economy” AND “Product Design”) | 597 | 48 |
DFX + CE | (“DFX” AND “Circular Economy”) | 13 | 13 |
DFX + Reuse | (“DFX” AND (“Reuse” OR “Reusability”)) | 21 | 16 |
DFX + EOL | (“DFX” AND (“EOL” OR “End of Life”)) | 16 | 11 |
DFX + Ecodesign | (“DFX” AND “Ecodesign”) | 32 | 7 |
Upgrade | (“Upgrade” AND “Product Design”) | 11 | 6 |
Repair and Maintenance | (“Repair” AND “Product Design” AND “Circular Economy”) | 55 | 9 |
(“Maintenance” AND “Product Design” AND “Circular Economy”) | 23 | 4 | |
Refurbish | (“Refurbished” AND “Product Design” AND “Circular Economy”) | 7 | 4 |
(“Refurbish” AND “Product Design” AND “Circular Economy”) | 4 | 2 | |
Remanufacture | (“Remanufacture” AND “Product Design” AND “Circular Economy”) | 17 | 9 |
Reuse | (“Reuse” AND “Product Design” AND “Circular Economy”) | 109 | 8 |
Repurpose | (“Repurpose” AND “Product Design" AND “Circular Economy”) | 4 | 4 |
TOTAL | 909 | 141 |
3.1.1 DFX approaches
Design for | CE Strategies | Related authors | ||||||
---|---|---|---|---|---|---|---|---|
R1 | R2 | R3 | R4 | R5 | R6 | R7 | ||
Assembly/disassembly | ●● | ●●● | ●● | ●●● | ● | ●● | ||
Durability | ●● | ●●● | ●●● | ●●● | ●●● | ●● | ||
Extended life—end of life (EOL) | ●● | ● | ●● | ● | ● | ● | ||
Emotional durability | ● | ●● | ● | ● | ● | |||
Maintainability | ●● | ● | ●● | ●● | ||||
Modularity | ●● | ●● | ●● | ●● | ●● | ●● | ||
Recycling | ●●● | |||||||
Recovering | ●● | |||||||
Refurbishing | ● | ● | ●●● | |||||
Reliability | ● | ●● | ● | ● | ||||
Remanufacturing | ● | ● | ●●● | |||||
Repairing | ●●● | ● | ●● | ●● | (den Hollander et al. 2017) | |||
Repurposability | ●●● | (Chouinard et al. 2019) | ||||||
Upgradability | ●●● | ● | ● | ● | ●●● | ● |
3.1.2 Circular products
Product attributes | CE strategies | ||||||
---|---|---|---|---|---|---|---|
R1 | R2 | R3 | R4 | R5 | R6 | R7 | |
Assemblability | (Mestre and Cooper 2017) | ||||||
Disassemblability | |||||||
Durability | |||||||
Modularity | (Talens Peiró et al. 2017) | ||||||
Simplicity | (Nurhasyimah et al. 2016) | (Talens Peiró et al. 2017) | (Bauer et al. 2020) | ||||
Standardization | (Simon 1993) | (Kwak and Kim 2011) | (Bauer et al. 2020) | ||||
Commonality | (Geng et al. 2014) | (Kwak and Kim 2011) | |||||
Affordability of spare parts | (Li et al. 2008) | (Kwak and Kim 2011) | |||||
Recyclability |
Attribute | Levels/scores | Description |
---|---|---|
Assemblability/disassemblability | High | All joints among parts are reversible |
Medium | At least 50% of joints among parts are reversible | |
Low | Less than 50% of joints among parts are reversible | |
Durability | High | All materials provide high mechanical and chemical resistance |
Medium | Majority of materials provide high mechanical and chemical resistance | |
Low | Few materials provide high mechanical and chemical resistance | |
Modularity | High | All parts follow a modular architecture |
Medium | Several parts follow a modular architecture | |
Low | None of the parts follow a modular architecture | |
Simplicity | High | The assembly has an intuitive structure, no complex geometries or specialized tool requirements |
Medium | The assembly has an intuitive structure, several parts present geometrical complexity | |
Low | The assembly does not have an intuitive structure, the majority of parts present geometrical complexity | |
Standardization | High | All joints are standardized. It is possible to find spare parts in the market |
Medium | Most joints are standardized. It is possible to find several spare parts in the market | |
Low | No standardized parts. Difficult to find spare parts | |
Affordability spare parts | High | Overrun cost is less than 25% |
Medium | Overrun cost vary from 26 to 50% | |
Low | Overrun cost is higher than 50% | |
Recyclability | High | All materials can be easily recycled |
Medium | Most materials can be recycled | |
Low | Just a few materials can be recycled |
Product Attributes | Generic Relevance respect to each CE strategy | ||||||
---|---|---|---|---|---|---|---|
R1 | R2 | R3 | R4 | R5 | R6 | R7 | |
Assemblability | 2 | 3 | 0 | 2 | 3 | 1 | 2 |
Disassemblability | 2 | 3 | 0 | 2 | 3 | 1 | 2 |
Durability | 2 | 3 | 3 | 3 | 3 | 3 | 0 |
Modularity | 2 | 2 | 2 | 2 | 2 | 2 | 0 |
Simplicity | 3 | 2 | 0 | 1 | 1 | 1 | 2 |
Standardization | 2 | 2 | 2 | 2 | 2 | 0 | 2 |
Commonality | – | – | – | – | – | – | – |
Affordability spare parts | 0 | 1 | 1 | 2 | 2 | 0 | 0 |
Recyclability | 0 | 0 | 0 | 0 | 0 | 0 | 3 |
3.2 Identification and analysis of DFX rules related to circular products
3.3 Definition of design rules for circular and durable products (DFCD)
Phase | Task | DFCD Rule |
---|---|---|
Conceptual design | Recognition of needs and definition of the problem | 101-Diagnose CE potential using quantitative tools or indicators |
102-Identify potential CE strategies suitable and according to the company’s strategic plan | ||
Gathering information | 103-Analyze state-of-the-art and existing approaches to the CE strategy in the type of product | |
Developing alternative design concepts | 104-Generate alternative design concepts, preferably using modular structuresa | |
Evaluation of concepts and selection | 105-Include evaluation parameters associated with CE attributes (assembly, disassembly, durability, standardization, simplicity, etc.)a 106-Hierarchize concepts based on the most interesting CE strategies scenariosa | |
Embodiment design | Definition of Product architecture | 201-Divide product into modules or subcomponents to facilitate assembly, disassembly, repair, and failure identification 202-Include, if possible, a secondary function for repurposing the product in its end of life 203-Include indicators or modules for self-diagnostic |
Preliminary selection of materials, modeling, and size of parts | 204-Select materials with low environmental impact 205-Select materials suitable for burning with a minimum of toxic, harmful emissions and avoid toxic substances 206-Select materials with high mechanical and chemical durability, especially those which comprise the enclosure or external layer of the product 207-Reduce the number of materials in the product. Use one kind of material 208-Include a high content of recycled material. Different materials should not be mixed 209-Use by-products or waste from other companies as raw material 210-Reduce the number of parts 211-Avoid components with large and complex shapes 212-Utilization of light components to facilitate disassembly and extraction of failed parts 213-Implementation of easy-to-use joints in the product 214-Avoid sharp edges and corners, and reduce, if possible, stress concentrators 215-Assures that non-recyclable parts or materials can be ecologically disposed 216-Standardize components and parts across a range of brands and products. Design the product as a member of a product family | |
Robust design, final dimensions/parameters, and tolerances, DFMA | 217-The design of the product should enable easy accessibility to components during disassembly and maintenance activities 218-Reduce the number and type of special tools and equipment required for disassembling. Use only hands if possible 219-Use, if possible, one type of joint method (i.e., threaded joints) 220-Select reversible and separable joints 221-Design core components with higher safety factors and reliability to enable future use cycles 223-Design joints and surfaces between joints using materials with high mechanical and chemical durability to face multiple disassembly and re-assembly cycles | |
Detailed design | Make/buy decisions | 301-Reuse of parts in the product. Reused parts are susceptible to being freshened up and reused 302-Make (if possible) parts using recycled material 303-Buy parts, if possible, to suppliers with CE practices |
Finalize selection and sizing of components | 304-Use standard components from the market 305-Use, if possible, the minimum variety of joints. Using a unique type is recommendable 306-Facilitate the identification of parts 307-Label parts for easy identification and classification of materials 308-Label parts with the date of manufacturing 309-Reduce the number of materials in the packaging 310-Design additional modules that can serve as upgrades or personalization functionalities 311-Design for allowing the user to personalize the product appearance (i.e., the user can paint its product or include a logo, tattoo, or text) | |
Complete engineering drawings | 312-Include identification of parts designed to be circularized according to the strategy 313-Specify surface treatments to polish and upgrade the product in terms of esthetics | |
Complete bill of materials | 314-Provide procedures for assembly and testing to verify the installation accuracy | |
Verification and prototype testing | 315-Generate a troubleshooting guide regarding potential product failures 316-Generate repair manual or handbook | |
Final cost estimate | 317-Calculate depreciation of parts based on the CE strategy selected 318-Calculate economic impact of repair, remanufacture, refurbish and reuse cycles | |
Prepare design project report | 319-Include section describing the design guidelines implemented and the detail of parts designed under such guidelines 320-Include detailed information to get spare parts from the manufacturer and repair shops 321-Include the process to get warranty extensions and compensation 322-Include detail of secondary functionalities in the case of repurposing |
Phase | Task | R1 | R2 | R3 | R4 | R5 | R6 | R7 |
---|---|---|---|---|---|---|---|---|
Conceptual design | Recognition of needs and definition of the problem | All guidelines apply to the seven CE strategies 101 102 103 104 105 106 | ||||||
Gathering information | ||||||||
Developing alternative design concepts | ||||||||
Evaluation of concepts and selection | ||||||||
Embodiment design | Definition of Product architecture | 201 203 | 201 203 | 201 203 | 201 203 | 201 203 | 201 202 | 201 |
Preliminary selection of materials and modeling of parts | 204 206 210 213 216 | 204 206 210 211 212 213 | 204 205 206 211 214 | 204 206 210 211 212 213 214 216 | 204 206 207 210 212 213 214 216 | 204 206 | 204 206 207 208 209 211 213 215 | |
Robust design, final dimensions/parameters, and tolerances, DFMA | 217 218 219 220 221 223 | 217 218 219 220 221 222 223 | 223 | 217 218 219 220 221 222 223 | 217 218 219 220 221 222 223 | 222 | 217 218 219 221 | |
Detailed design | Make/buy decisions | 303 | 303 | 303 304 | 303 304 | 303 304 | 302 303 | |
Finalize selection and sizing of components | 304 305 306 308 310 311 | 304 305 306 308 | 306 308 311 | 305 306 308 309 | 305 306 308 309 310 | 304 305 308 310 311 | 305 307 308 | |
Complete engineering drawings | 312 313 | 312 313 | 312 313 | 312 313 | 312 313 | 312 313 | 312 | |
Complete bill of materials | 314 | 314 | 314 | 314 | ||||
Verification and prototype testing | 315 316 | 316 | 316 | |||||
Final cost estimate | 317 318 | 317 318 | 317 318 | 317 318 | 317 318 | 317 | ||
Prepare design project report | 319 | 319 320 321 | 319 321 | 319 320 | 319 320 | 319 322 | 319 |
4 Case study
4.1 Conceptual redesign
Part | Material | Geometry | Joints |
---|---|---|---|
Top frame | Steel | Tube | Threaded, press fit |
Bottom frame | Steel | Tube | Threaded, press fit |
Handlebars | Steel (Chromated) | Tube | Press fit |
Fork | Steel | Tube + Sheet | Threaded |
Seat with post | Steel + Polystyrene + Rubber | Tube | Threaded, press fit |
Front wheel | Steel + Rubber | Sheet + wire | Threaded |
Rear wheel | Steel + Rubber | Sheet + wire | Threaded |
Bottom step rod | Steel (Chromated) | Tube | Threaded, press fit |
Bottom step | Steel | Sheet | Press fit |
Top step | Steel | Sheet | Threaded |
Bell | Steel | Various | Threaded |
Cap | Rubber | Tube | Threaded |
Fender | Steel (Chromated) | Sheet | Threaded |
Grip | Rubber | Tube | Press fit |
Handlebar clamp | Steel (Chromated) | Tube | Threaded |
Pedal | Polypropylene | Injected | Threaded, press fit |
Wheel Spacer | Steel | Sheet | NA |
Fork Axle Hold | Steel | Sheet | Threaded |
Tricycle Attributes | Valuation | R1 | R2 | R3 | R4 | R5 | R6 | R7 |
---|---|---|---|---|---|---|---|---|
Assemblability | High (3) | 2 | 3 | 0 | 2 | 3 | 1 | 2 |
Disassemblability | High (3) | 2 | 3 | 0 | 2 | 3 | 1 | 2 |
Durability | Medium (2) | 2 | 3 | 3 | 3 | 3 | 3 | 0 |
Modularity | Medium (2) | 2 | 2 | 2 | 2 | 2 | 2 | 0 |
Simplicity | Medium (2) | 3 | 2 | 0 | 1 | 1 | 1 | 2 |
Standardization | Medium (2) | 2 | 2 | 2 | 2 | 2 | 0 | 2 |
Commonality | NA | – | – | – | – | – | – | – |
Affordability spare parts | Medium (2) | 0 | 1 | 1 | 2 | 2 | 0 | 0 |
Recyclability | High (3) | 0 | 0 | 0 | 0 | 0 | 0 | 3 |
Overall Score | 30 | 38 | 16 | 32 | 38 | 18 | 29 |
4.2 Embodiment and detailed redesign
Phase | DFCD Rule | Description |
---|---|---|
Embodiment redesign | 206 | Select materials with high mechanical and chemical durability |
207 | Reduce the number of materials | |
213 | Implementation of easy-to-use joints | |
216 | Standardize components | |
218 | Reduce the number and type of tools | |
220 | Use reversible and separable joints | |
221 | Design core components with higher safety factors | |
Detailed redesign | 306 | Facilitate the identification of parts |
308 | Label parts with the date of manufacturing | |
310 | Design additional modules that can serve as upgrades | |
312 | Include identification of parts designed to be circularized |