Using Design Requirements for Environmental Assessment of Products

156 Pages·2016·5.03 MB·English

by  Darian Alexis Visotsky

Clemson University
TigerPrints
All Theses Theses
8-2016
Using Design Requirements for Environmental
Assessment of Products
Darian Alexis Visotsky
Clemson University, [email protected]
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Visotsky, Darian Alexis, "Using Design Requirements for Environmental Assessment of Products" (2016).All Theses. 2431.
https://tigerprints.clemson.edu/all_theses/2431
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USING DESIGN REQUIREMENTS FOR ENVIRONMENTAL
ASSESSMENT OF PRODUCTS

A Thesis
Presented to
the Graduate School of
Clemson University

In Partial Fulfillment
of the Requirements for the Degree
Master of Science
Mechanical Engineering

by
Darian Alexis Visotsky
August 2016

Accepted by:
Dr. Joshua Summers, Committee Chair
Dr. Gregory Mocko
Dr. Rodrigo Martinez-Duarte
ABSTRACT
The growing concern about environmental issues from different sectors of the
scientific community, politics, and society in general, has incremented the pressure on
industries to develop more environmentally friendly products. A review on published
literature revealed that the tools available to assess the environmental impacts of products
can only be performed when at least an embodiment of the design is achieved, while, like
other aspects of the products, their environmental performance is more greatly impacted
during stages of the design process even previous to the embodiment phase. The objective
of this thesis is to study if the environmental performance of a product can be predicted
from the requirements list elicited early on in the design process. For this purpose, an
environmental assessment tool –Streamlined Life Cycle Assessment, SLCA- is used to
estimate the environmental performance of final products, while an assessment tool for
requirements based on a rubric is developed to evaluate the requirements list of those same
products in terms of environmental impacts. The discovery of relationships between the
data obtained from the requirements rubric and the SLCA scores is performed using an
artificial neural network (ANN) model. The products used for the study are fifteen projects
developed by senior students in a mechanical engineering design course, because of the
availability of design information –mainly the requirements lists. The results show that the
predictions are stable, with residual errors of less than half the range of target values.
However, the accuracy of the predictions, and the ranking order of the predicted scores
when compared with the targets, are dependent on which products are selected for training
and for testing. The reasons for these inconsistencies are analyzed, being the most
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important that the products used for the study may not consider environmental issues
during their design process, particularly when eliciting the requirements. Opportunities for
future work are identified to improve the method for early assessment of environmental
impacts of products, and for using design requirements to predict other traits of product
design, such as market cost or assembly time.
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DEDICATION
To Vivi, my love and partner in life.
To my parents, Marta and Juan, for their support and for believing in me.
And to my sisters, niece and nephews, with whom I am grateful to share
all the essential experiences.
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ACKNOWLEDGMENTS
I would like to thank my advisor, Dr. Joshua Summers for his support and guidance
throughout the course of this work. Also, I would like to acknowledge my committee
members, Dr. Gregory Mocko and Dr. Rodrigo Martinez-Duarte for their valuable input
on this thesis. Another big thank you to all the members of the CEDAR Group, from whom
I have learned so much. Special thanks to Apurva Patel, Stephan Knackstedt and
Amaninder Gill for their assistance at various stages of this work.
This experience as a Graduate Student would not have happened without the
funding and support provided by the Argentinean State through the BEC.AR Program.
Thank you to all the people involved in this great endeavor for believing in us.
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TABLE OF CONTENTS
Page
ABSTRACT ......................................................................................................................... i
DEDICATION ................................................................................................................... iv
TABLE OF CONTENTS ................................................................................................... vi
LIST OF TABLES ........................................................................................................... viii
LIST OF FIGURES ............................................................................................................ x
Chapter 1: MOTIVATION AND BACKGROUND ON REQUIREMENTS AND
ENVIRONMENT ............................................................................................. 1
1.1 Themes that motivate this work ........................................................................ 6
1.2 Design requirements ......................................................................................... 9
1.3 Sustainability and environmental assessment tools ........................................ 13
1.4 Artificial neural networks ............................................................................... 23
1.5 Research question ........................................................................................... 26
Chapter 2 STREAMLINED LIFE-CYCLE ASSESSMENT OF PRODUCTS ............... 28
2.1 SLCA as a tool for environmental assessment of products ............................ 28
2.2 Products used for investigation ....................................................................... 37
2.3 Application of SLCA on products .................................................................. 53
Chapter 3: RUBRIC FOR REQUIREMENTS BASED ASSESSMENT OF
PRODUCTS .................................................................................................... 61
3.1 Requirements of the projects .......................................................................... 61
3.2 Development of rubric .................................................................................... 64
3.3 Stabilization of rubric output .......................................................................... 68
3.4 Assessment of products with rubric ................................................................ 71
Chapter 4: ANALYSIS AND RESULTS ......................................................................... 74
4.1 Predictions of SLCA scores ............................................................................ 74
4.2 Predictions when removing requirements ....................................................... 88
Chapter 5: CONCLUSIONS AND FUTURE WORK ..................................................... 94
5.1 Conclusions derived from this research .......................................................... 95
5.2 Research limitations ........................................................................................ 97
5.3 Proposed future work ...................................................................................... 98
APPENDICES ................................................................................................................ 100
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Table of Contents (Continued) Page
Appendix A One-page tutorials to use environmental assessment tools ............... 101
Appendix B SLCA of ME-401 Projects - Characterization of Life Cycles ........... 103
Appendix C Test of rubric to determine interrater agreement ............................... 118
Appendix D Assessment of requirements with rubric ........................................... 119
Appendix E Histograms of distributions of ANN predictions ............................... 134
REFERENCES ............................................................................................................... 137
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LIST OF TABLES
Page
Table 1.1: Comparison of the sources of requirements for different authors ................... 11
Table 1.2: Uses of requirements according to Handbooks from different disciplines ...... 13
Table 1.3: Environmental assessment tools evaluated by convenience of cost of use,
simplicity and effectiveness ............................................................................ 21
Table 2.1: Comparison of SLCAs and LCAs ................................................................... 30
Table 2.2: The ERP Assessment Matrix, where the numbers are the matrix element
indices i,j ......................................................................................................... 36
Table 2.3: ERP Assessment for “Project 01 - Vacuum forming system” ......................... 54
Table 2.4: ERP Assessment for “Project 02 - Wind Tunnel A” ....................................... 54
Table 2.5: ERP Assessment for “Project 03 - Wax Casting with Metallic Particles” ...... 55
Table 2.6: ERP Assessment for “Project 04 - Plastic Bag Fusion and Vacuum Forming
Process”........................................................................................................... 55
Table 2.7: ERP Assessment for “Project 05 - Wind Tunnel 4” ........................................ 55
Table 2.8: ERP Assessment for “Project 06 - Virtual Reality 1” ..................................... 56
Table 2.9: ERP Assessment for “Project 07 - Vertical scissor press” .............................. 56
Table 2.10: ERP Assessment for “Project 08 - Wind tunnel 3” ....................................... 56
Table 2.11: ERP Assessment for “Project 09 - Wind tunnel 2” ....................................... 56
Table 2.12: ERP Assessment for “Project 10 - Augmented reality 2” ............................. 57
Table 2.13: ERP Assessment for “Project 11 - Laser engraver prototype” ...................... 57
Table 2.14: ERP Assessment for “Project 12 - Injection molding demonstrator”............ 57
Table 2.15: ERP Assessment for “Project 13 – Vacuum Thermoformer Design” ........... 58
Table 2.16: ERP Assessment for “Project 14 – Mechanical Thermoforming” ................ 58
Table 2.17: ERP Assessment for “Project 15 – Metal stamping device” ......................... 58
Table 2.18: Weights assigned to each life stage ............................................................... 59
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List of Tables (Continued) Page
Table 2.19: Final results for the SLCA performed on the 15 projects .............................. 60
Table 3.1: Example of requirements for Project 5 – Wind tunnel 4 ................................. 62
Table 3.2: Questions of rubric for requirements based assessment of designs ................. 67
Table 3.3: Interrater agreement for testing of rubric ......................................................... 69
Table 3.4: Characterization of agreements for rubric test ................................................. 70
Table 3.5: Results of assessment with rubric of fifteen products used for investigation .. 72
Table 4.1: Results obtained for different sets of products used for training, with
vocabulary processing method ........................................................................ 77
Table 4.2: List of the 29 complexity metrics used in the graph complexity connectivity
method............................................................................................................. 81
Table 4.3: Results obtained for different sets of products used for training, with graph
complexity connectivity method ..................................................................... 82
Table 4.4: Comparison of results across trials, for VP and GC methods ......................... 87
Table 4.5: ANOVA tests to determine significant differences between VP and GC
methods ........................................................................................................... 88
Table 4.6: Predictions for Product 7 when removing requirements, using VP method.
Every group contains a different set of randomly removed requirements ...... 89
Table 4.7: Predictions for Product 7 when removing requirements, using GC method.
Every group contains a different set of randomly removed requirements ...... 91
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