Sustainability in Product Design and Manufacturing Albert Puzzuoli,

Nael Barakat, Ph.D., P.Eng.

Graduate Student General Motors Corporation 300 36th Street Wyoming, MI 49548 586-212-7598 [email protected]

Grand Valley State University School of Engineering, KEN 136 301 W Fulton Grand Rapids, MI. 49546 616.331.6825 [email protected]

Abstract Natural resources continue to be consumed as the world population continues to increase. An imbalance in this cycle is evident in environmental changes and resource challenges, which lead to a significant concern for the survival of future generations. Sustainable designs aim to meet the needs of society without interfering with the ability of future generations to meet their own needs. This is partially the responsibility of the end user as products are often developed based on consumer demand. But, some of these choices are made out of necessity regardless of the products origin, design, or method of production. An engineer is given the task to develop and design per a set of objectives, but these should not limit the scope of an engineer’s work. Engineers have the skills and knowledge, along with an ethical responsibility, to design for sustainability. The need for sustainability has been clearly presented but our current design objectives do not account for this. This paper defines sustainability and its importance in a historical context. It addresses the ethical responsibilities of an engineer regarding the topic of sustainability and explores the potential controversy around sustainability in design and manufacturing of products. Sustainability can easily be overlooked during the design stage but can be better incorporated at a lower cost when considered as a part of the overall design intent. A guideline for incorporating sustainability into the design and manufacturing process is proposed and applied through theoretical case studies. Keywords Sustainability Sustainable Development Sustainable Design Introduction During the twentieth century, the world population growth exceeded 4 billion and is estimated at 6.7 billion today [1,2]. Although it has appeared that the growth rate has decreased, the overall world population continues to increase. More people equals more consumption, increased pollution, and greater demands for the earth’s natural resources. However, this resource reduction is not only due to population increase but is the result of an imbalanced cycle in which our consumption rate is greater then that of the earth’s ability to replenish those resources. This imbalance results in a concern for the survival of future generations. Helping to resolve these issues will require cooperation from the general population. Each individual should modify their behavior to reduce their effect on the environment by incorporating Proceedings of the 2009 American Society of Engineering Education (ASEE) – North Central Section (NCS) spring conference, Grand Rapids, MI. USA, Copyright © 2009 ASEE – NCS.

measures like recycling and waste reduction whenever possible. However, some things are easier to recycle and others can not be recycled at all. We often have limited alternatives when using natural resources like in the case of fossil fuels. Engineers can be a huge asset with solving these issues by incorporating sustainability into their designs. Sustainability meets the needs of society without interfering with the ability of future generations to meet their own needs [3]. Considering sustainability during the design process helps to incorporate it at a products conception allowing the benefits to be felt throughout the entire life of the product. This paper will explore sustainability and why it should be incorporated within engineering design. It will review the ethical responsibilities of an engineer as it relates to sustainability. Most importantly, it will discuss how sustainability can be incorporated within a design. Sustainability is often referred to as a goal but this should not be the case. With the increase in population and the decrease in resources; along with so many other incorporated variables, sustainability can never be achieved. Alternatively, sustainability can be considered a process; a process for achieving a balance between the rate of consumption vs. replacement. For the purposes of this paper, sustainability and sustainable development are interchangeable terms with the same meaning. Although relatively new, both are commonly used today. Rational The first step to incorporating sustainability is to understand and recognize the need for it. The main goal behind sustainability is to allow mankind to succeed indefinitely. Assuming that future generations have similar needs, they will continue to necessitate the resources we are currently using today. It could be argued that the needs of the future will differ as technology evolves, i.e. alternative propulsion systems, or advanced manufacturing methods; or as resources become restricted, costs will rise and demand will decrease. However, at this time the future is unknown, and choosing not to work towards sustainability could be deemed an unethical practice. Canon 1 of the National Society of Professional Engineers (NSPE) states, “Engineers, in fulfillment of their professional duties, shell hold paramount the safety, health, and welfare of the public [4].” Sustainability is directly related to the safety, health, and welfare of the future public and failure to consider sustainability during design would be a failure to fulfill ones ethical duties. In addition, many of the engineering codes have added statements for the protection of the environment and incorporation of sustainable development. The American Society of Civil Engineers (ASCE) states, “Engineers shall hold paramount the safety, health and welfare of the public and shall strive to comply with the principles of sustainable development” [5]. Life Cycle Assessment As previously stated, sustainability is a process for achieving balance between the rate of consumption vs. replacement. Alternatively, it can be viewed as a balance between our inputs and outputs; meaning those things removed from the environment (inputs) and those which are put in to the environment (outputs) [6]. Considering the inputs first, there is the concern for the depletion of resources. For example, at the current rate of consumption, there are beliefs that the world’s oil will run out. An alternative to depletion is the modifying of the ecosystem as a bi-product of another action. For example, harvesting a forest for the lumber industry; the trees can be replanted but the initial effects will displace wildlife and allow erosion to occur. The outputs encompass those things Proceedings of the 2009 American Society of Engineering Education (ASEE) – North Central Section (NCS) spring conference, Grand Rapids, MI. USA, Copyright © 2009 ASEE – NCS.

created using the inputs. Figure 1 represents the system of inputs and outputs and provides examples of each.

Figure 1: Resources (inputs) are removed form the environment and are reintroduced as a by-product or form of waste (output) [7]

A product is traditionally designed to meet the expectations of the end user. This primarily includes function, quality, and cost; as these characteristics directly relate to the consumer. However, it’s these characteristics that may prevent an engineer’s design from incorporating sustainability; but this should not be the case because a sustainable design will improve these characteristics. To begin to understand how, one must first understand a products life cycle. Every product has a life cycle which begins with the acquisition of raw materials and ends with the disposal of the item. This is often depicted using the phrase “cradle-to-grave” because the process starts with the removal of a raw material from the earth and ends with the return of the material to the earth. Carlo Vezzoli and Ezio Manzini, co-authors of Design for Environmental Sustainability [6], divide a products life cycle in to the following five major phases: • Pre-production • Production • Distribution • Use • Disposal Life Cycle Assessment (LCA) is a process of evaluating the potential effects a product has on the environment during each of these major phases. Because LCA is a continuous process (Figure 2), one can evaluate an individual phase or the entire process. The pre-production phase incorporates the acquisition of raw materials and creation of components for the final product. Raw materials can be a renewable or non-renewable resource. Renewable resources are those resources that can replenish themselves over time; and non-renewable resources will eventually Proceedings of the 2009 American Society of Engineering Education (ASEE) – North Central Section (NCS) spring conference, Grand Rapids, MI. USA, Copyright © 2009 ASEE – NCS.

diminish. A sustainable alternative to these would be a recycled resource. Recycled resources can be classified as pre or post consumption.

Figure 2: Product Life Cycle Assessment [6].

Pre-consumption describes the waste generated during the production process and postconsumption is waste that has gone through an end user [6]. It is important to understand that post-consumption waste generally requires more processing, i.e. energy, to re-create a usable resource. The production phase consists of the manufacturing, assembly, and completion of the product. It is during this phase that the previously acquired raw material will be transformed into the final product. Manufacturing and assembly encompasses an infinite number of methods which extend beyond the scope of this paper. However, selecting the appropriate method and avoiding overproduction are necessary for sustainability. The distribution phase includes the packaging, transportation, and storing of the final product. Packaging should sufficiently protect a product for the end user without being overly robust. It should be reused when possible and avoided unless necessary. Transportation is performed using a variety of methods and can rarely be avoided. Distribution consumes energy during transit and both the selected method of transportation and the packaging incorporate a life cycle of their own which should be evaluated. The use phase consists of the intended utilization and consumption of the product as well as its maintenance and service requirements. Energy is often required when utilizing a product and waste is usually generated. Both of these should be minimized through design, however, the end user has a significant role in doing this. The maintenance and service requirements should be designed to be as easy as possible as not to discourage the consumer from performing tasks that are essential for product longevity. The disposal phase is the final stage of a products life cycle and is dictated by the end user and/or product failure. At this time it should be determined if a product can be Proceedings of the 2009 American Society of Engineering Education (ASEE) – North Central Section (NCS) spring conference, Grand Rapids, MI. USA, Copyright © 2009 ASEE – NCS.

restored/repaired or must be discarded. This may be determined by the cost, availability of parts, and/or ease of repair. However, a product may require disposal when it is beyond repair or deemed obsolete, as with computer hardware or electronic devices. There are three solutions for a product that must be disposed: • Composted • Incinerated • Recycled Composed trash is most commonly placed in a landfill and incinerated trash is burned until only ashes remain. Placing trash in landfill will require the earth to decompose the item which can often take centuries while depositing harmful chemicals into the environment. Incinerating trash will keep it out of the ground but will still cause air pollution. Recycling is a sustainable alternative that falls within two categories: • Closed loop recycling • Open loop recycling Closed loop recycling is when a product is deconstructed and used to manufacture a similar product. Open loop recycling is when a produced is deconstructed and used in any way or form [6]. Closed loop recycling is the preferred, but harder to obtain, option. Application and Design Considerations When initiating a product’s design an engineer should consider the product’s life cycle and apply LCA accordingly. As implied, some portions of the LCA process may be ignored depending on the product. For example, the infrastructure of a house or building is intended to remain indefinitely so the disposal phase would be given less consideration. However, with an understanding of the products intent an engineer should consider each phase of its life cycle as an opportunity for incorporating sustainability. To properly design a product for sustainability, an engineer should pre determine a product’s life cycle at the initial stages of its development and make the appropriate design considerations. The United Nations Environmental Program and Delft University of Technology, co-authors of Design for Sustainability: A Practical approach for Developing Economies [8], define the following design strategies: • Select low-impact materials like a renewable or previously recycled resource. • Reduce material usage through design improvements such as an adding reinforcement gussets in place of ‘excessive dimensioning.’ • Optimize production techniques in effort to increase throughput and reduce scrap. • Improve product distribution with innovative packaging and product weight and/or size reduction. • Reduce a products impact based on its intended use. • Extend a product’s life by reducing the amount of required maintenance and making necessary maintenance easily executable. • Optimize the disposal phase by promoting product recyclability. If not already interpreted, improving one design strategy will like better another. For example, General Motors Corporation incorporated a hydroformed front engine cradle into the design of its 2008 Pontiac G6, eliminating several steps in the manufacturing process and reducing scrap. A traditional engine cradle would have required the assembly of several stamped components, requiring additional resources (e.g. material, equipment). The hydroformed component is also stronger and lighter which reduces shipping and overall vehicle weight [9]. Proceedings of the 2009 American Society of Engineering Education (ASEE) – North Central Section (NCS) spring conference, Grand Rapids, MI. USA, Copyright © 2009 ASEE – NCS.

As previously mentioned, consumers have a key role in sustainability as they are responsible for product use and disposal. It is impossible to dictate a person’s actions once a product has been purchased so one cannot guarantee a product will be maintained properly or disposed of accordingly. However, an engineer should encourage sustainability by: • Informing the consumer • Providing a sustainable option • Making the sustainable option easily executable A consumer may neglect to choose a sustainable product or action do to lack of knowledge. This may be as easy as an additional photograph or line of text on a product’s label. Figure 3 is an example of recycling label commonly found on rechargeable batteries. This label provides a toll free number for locating your nearest battery recycling center.

Figure 3: A recycling label commonly found on rechargeable batteries. [10]

Providing a sustainable option is necessary if sustainability is to exist. As previously stated, many products are purchased out of necessity regardless of their environmental impact. A sustainable option can be an alternatively packaged item or making replacement parts readily available. For example, Church & Dwight Company, makers of Arm & Hammer Multi Surface Cleaner now offer their product as a refill. The company says the main ingredient of their traditionally packed products is water which can be added by the consumer. By eliminating this ingredient, the company has reduced their packages size, streamlined their manufacturing, and reduced shipment weight; which reduces the products environmental impact and cuts costs [11]. These costs savings are passed on to the consumer giving the product environmental and economical benefits [12]. If a sustainable option is not easily executable it will not succeed. This can be applied to the previous example of the household cleaner. If purchasing the refill requires the consumer to perform extensive measuring or if the main ingredient (water) was not readily available, the consumer is unlike to embrace the product. Recycling has already been described as a sustainable alternative during the disposal phase of LCA but optimizing a product’s recyclability requires premeditated design considerations. Gunther Seliger, author of Sustainability in Manufacturing [13], has developed design guidelines emphasizing the disassembly and recyclability of a product. Emphasis is placed on material selection, product structure and connection methods. The selected material should be previously recycled or at a minimum, recyclable. The variety of materials should be limited and sub-assemblies should be made of the same material or ones with similar recycling properties. Finally, all materials should be marked so they are identifiable during recycling. The products structure should be created with the use of standard components or assemblies and the total number of parts should be minimized. When assembling a product the number of connections should be reduced and for those unavoidable connections the following should be considered: Proceedings of the 2009 American Society of Engineering Education (ASEE) – North Central Section (NCS) spring conference, Grand Rapids, MI. USA, Copyright © 2009 ASEE – NCS.

• • •

Reduce the variety of connections Choose fasteners that can be removed with standard tools Avoid connections requiring destructions separation (e.g. glue, rivets, weld) Selecting the appropriate fastener for a product will simplify deconstruction and assist when performing maintenance. Conclusion Sustainability has become a necessary component of the design process and incorporating it at a products conception allows the benefits to be felt throughout the product’s life cycle. Although intended to protect future generation’s abilities to meet their own needs, sustainability is actually becoming a way of incorporating cost savings for both the manufacture and consumer. Corporations have even started to showcase their sustainable practices through marketing campaigns in an effort to attract more sales. Regardless of the motivator, engineers have an ethical responsibility to incorporate sustainability within their designs. References 1. "The World at Six Billion." UN.org. United Nations. 9 Nov. 2008 . 2. "2008 World Population Data Sheet." PRB Population Reference Bureau. 9 Nov. 2008 . 3. World Commission on Environment and Development. Our Common Future. Oxford University Press. The Brundland Report, Oxford, UK 1987 4. Harris, Charles E., Michael S. Pritchard, and Michael J. Rabins. Engineering Ethics : Concepts and Cases. Fourth ed. Belmont: Wadsworth, 2008. 194+. 5. "Code of Ethics." American Society of Civil Engineers. Nov. 1996. ASCE. 16 Nov. 2008 . 6. Vezzoli, Carlo, and Ezio Manzini. Design for Environmental Sustainability. London: SpringerVerlag, 2008. 7. Curran, Mary A. Life Cycle Assessment: Principles and Practice. United States. Environmental Protection Agency. National Risk Management Research Laboratory. Cincinnati, OH, 2006. 8. Crual, M.R.M., J. C. Diehl, and Delft University of Technology, Faculty of Industrial Design Engineering. Design for Sustainability: A Practical Approach. Division of Technology, Industry and Economics, United Nations Environment Programme. D4S Design for Sustainability. 30 Nov. 2008 . 9. "Environmental Features of GM's Vehicles and Facilities." Environmental Commitment. 2008. GM. 30 Nov. 2008 . 10. Rechargeable Battery Recycling Corporation. RBRC. 18 Nov. 2008 . 11. "Arm & Hammer ‘Essentials’ Dumps Bottle, Cuts Supply Chain Emissions." Environmental Leader. 29 Sept. 2008. 18 Nov. 2008 . 12. "ARM & HAMMER® Essentials Multi Surface Refill." GreatCleaners.com. Church & Dwight Co., Inc. 18 Nov. 2008 . 13. Seliger, G. Sustainability in Manufacturing : Recovery of Resources in Product and Material Cycles with Contributions by Numerous Experts. New York: Springer London, Limited, 2007. 143-46.

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