DfE basics

An introduction to concepts that drive Design for the Environment.


DfE is challenging. Do you go with a snap-fit or an adhesive? Which is less expensive in your factory? Which is easier to disassemble? The snap-fit requires a new mold, but the adhesive requires an automated gluing machine. Which is cheaper?

What if products were designed with ingenious connectors that allow quick and easy disassembly? Products could be cost effectively repaired then disassembled at the end of their usefulness to recover and reuse materials.

What if all plastic parts in products were clearly marked by resin type, kept uncontaminated by paint, and no hazardous materials were used during manufacturing? Uncontaminated materials could be reused in other products and there would be no assembly workers exposure to hazardous materials.

These are some of many benefits that can result from integrating design for the environment (DfE) into product design processes.

 

Should your product be easy to take apart using destructive methods, or should it be designed for reuse after take apart using nondestructive methods? How do you determine the environmental cost of a component or material you purchased? Should you care about the amount of electricity used in the steel mini-mill to make the 1/8 inch sheet that is part of your product?

All other things being equal, consumers will not pay more for a product that is environmentally-conscious. They may choose an environmentally-sound product if it costs the same as a competing product, and thus "green" can be played up in marketing your product, but you cannot charge more. Thus, the challenge is to design a green product at same or lower cost.

Why bother? The simple answer is: regulations. Like it or not, your life as a product designer will be driven by regulations. Europe is leading the pack when it comes to regulations that require green products. In the U.S., California leads the way. So, if you want to sell your product in Europe, or if you want to sell it in California, you will sooner or later become very familiar with DfE prinicples and DfE regulations. Even if you plan regional sales only, the U.S. is inevitably moving towards a national regulatory environment that will dictate environmentally sound products. Enlightened companies recognize this and are getting a head start with good DfE practices right now. Most other companies will be very far behind when the regulations hit.

Global initiatives are requiring greater product responsibility from producers. In Europe and Asia, new regulations are driving product take-back. For these products to be cost effectively disassembled, they need to be designed for ease of disassembly and with minimal use of hazardous materials that are expensive to process such as mercury or lead.

Use of DfE can also provide a marketing edge, especially to customers in Europe and Asia. For example, manufacturers such as Del Computer and IBM tote innovative product features developed from DfE in printed promotional materials.

DfE does not imply that a product is designed solely for the environment or that the environment is the only consideration. Rather, DfE should be an integral part of the product development process, and treated simply as one of the "design for X" (DfX) tasks that all good product design teams consider. The 'X' in DfX can be manufacturability, or safety, or cost, or environment.


Guiding Prinicples

DfE is driven by three main principles:

  1. The entire life-cycle of a product is accounted for.
  2. DfE is first considered during the early stages of the design cycle.
  3. Specific design methods exist for guiding a good DfE process.

The following sections cover each of these points in turn.


Life-Cycle Approach

Good DfE process requires that the environmental impact of a product be considered over its entire life-time. Some products impact the environment most at the manufacturing stage, for example, a tremendous amount of toxic chemicals are used and discarded when making coated papers. Others have more impact during the use stage; automobiles come immediately to mind here. Still others have the most impact when they are discarded, for example batteries that are almost impossible to discard safely.

There are five major periods in a product's life-cycle.

STAGE 1: Premanufacture is the extraction of materials from the earth and creation of component parts by vendors supplying your company. Here one must consider the environmental impact of virgin materials extraction and the processes used by your vendors to fabricate the raw materials and components you buy.

STAGE 2: Manufacturing is the steps taking place in your factories used to machine, process and assemble your product.

STAGE 3: Product distribution is all the activities related to packaging and shipping your product to the end user.

STAGE 4: Customer use includes the environmental impact of your product when used normally by the customer.

STAGE 5: End of life is what happens after the product leaves the customer's hands and is recyled, refurbished or discarded into a land-fill or incinerator.

The significance of taking a life-cycle approach is that it forces the design team to consider the overall environmental impact of the product, not just its impact during manufacture and use. A narrow-minded design team will take a "not my problem" attitude when considering the impact of mining procedures used to create steel stock from virgin materials. A good design team will consider the use of steel coming from a recycling mill that takes in scrap and produces raw parts. This is not a simple assessment because recycled steel may not have the needed strength nor finish characteristics needed and recycling mills still consume considerable amounts of energy in their steel fabrication process.

Here are some questions that your design team could ask when considering each stage of your product's life-cycle

Stage Questions to ask
Supplier Are the parts and materials coming from suppliers that have a good environmental track record?
Manufacture Is the use of hazardous materials avoided during manufacturing?
Distribution Is packaging minimized and is reusable transport packaging (such as collapsible totes) used to transport the product?
Use Is the use of disposable 'one time use' cartridges, containers, or batteries avoided? Is the product energy efficient?
End-of-life Is the product easy to disassemble for reuse or recycling of materials?

 

"Life-Cycle Analysis" (LCA) is a term tossed around by the DfE community that novice designers may come up against. LCA is a more detailed process for considering environmental effects at each life-cycle stage, and come with formal methods and metrics. For details, consult the books listed in the print resources section. For capstone design teams (and for many industry design teams), a full LCA analysis is overkill.


Being proactive

DfE must be part of the design process from the very begining, right there with design for cost, design for manufacturability and design to meet customer needs. A good design team takes a proactive approach to DfE and looks at the product throughout the design process, rather than simply trying to deal with environmental regulations at the end. It is impossible to do a good job designing to minimize environmental impact if DfE is tacked on after the bulk of the detailed design has been completed.

For example, rather than trying to figure out how to recycle a product containing mercury and lead, why not ask if the mercury and lead have to be in the product in the first place. For example, leading edge fishing tackle companies are getting the lead out of their sinkers because they see the not-too-distant-in-the-future day when the first state bans lead fishing tackle.


Design methods

DfE is more than just principles, it is backed up by specific design methods that all product designers should be familiar with. One category is DfE assessment methods, that is, methods to evaluate existing or proposed products to determine their overall environmental impact. Commonly known as "DfE Tools", these methods are a variety of questionnaires and spreadsheets used to qualify or quantify the total impact of a product during all five product cycle stages. Some tools are quite simple, some are exceedingly complex. Most product design teams need only use one of the simple tools because the main value of using a DfE tool is to force the design team to think about environmental impact. The complex tools are used for special cases, for high-volume manufacture, or when a formal LCA analysis is required by a customer.

The second category covers design methods that help to reduce the product's impact on the environment. These include design for disassembly and reuse, which covers effective methods of fastening and joining; design to minimze power use, which covers methods of minimizing the amount of power consumed by a product during use; and material selection in design, which covers use of environmentally friendly materials.

The third category is methods for informing others how to use your product responsibly and how to care for the product at the end of its life. These methods cover labeling of the product and component parts, and instructions.

For more on these design methods, use the links in the table of contents.