A design for lifecycle: Adopting a holistic approach to design

A design for lfiecycle: How engineers and business can adopt a holistic approach to design

Depending on your company and sector you may know it as sustainable design, eco design, lifecycle design or system design. They all mean pretty much the same thing and it is a philosophy that is gathering pace and moving upstream from the detailed design stage to more conceptual design.

So what is it? The term 'sustainability' is increasingly finding its way as a heading on corporate websites and brochures. The term can be a bit misleading and is more of an ideology, at the moment at least, which incorporates reducing the environmental burden rather than being truly sustainable. The reality is engineers and designers have to be more efficient than ever and deliver better, faster and cheaper products that are now also greener.

Chris Sherwin, head of sustainability at product design consultancy Seymour Powell, says: "Last year I sat in on a meeting with the CEO of a seriously large global engineering firm. His business strategy and sustainability strategy are pretty much one in the same. This is a huge €15billion business that has enormous impact across things like the packaging supply chain. The changes that these guys make have ripple effects down through the supply chain."

While marketeers love the term sustainability many engineers are asking what it actually means and asking for it to be quantified. Really it is about taking a systems approach to design. And what that means is considering the through life impact and effects a product has from the so called cradle-to-grave or dust-to-dust, depending on what terminology you prefer.

Many companies already assess the cradle-to-grave of products carrying out a life cycle assessment (LCA). Essentially this is what sustainable design encompasses. LCA's are becoming increasingly used by businesses to ascertain just what all the hidden environmental impacts are, and highlight inefficiencies. However, LCA tends to come after a product has been designed and tested, and production is underway. It is estimated that about 80% of a products carbon emissions are locked in at the design phase. Yet the information about this only becomes available when a change is difficult and costly to implement.

"Doing it later is corrective," says Powell. "You have to go back and redesign a product that you got wrong in the first place. We should be moving this philosophy of systematic design out of the detailed design stages, out of this corrective based model, and into conceptual design."

While the natural assumption is that this is all about environmental impact, and to a degree it does all harp back to it, it is about efficiency. Having an efficient design that can be made efficiently in an efficient supply chain that can be easily reused or recycled ultimately saves money, and that has to be good for any product and organisation.

Design engineers have enormous power and opportunity here. Those early decisions lock in materials, which in turn locks in a supply chain, manufacturing processes, the way a facility is laid out, and the type of transportation needed. Design locks in environmental impact and embeds CO2. And it also locks in cost from production to materials to disposal.

There is no doubt the motivation is there, however looking at products in this systematic way often throws up unforeseen impacts and seemingly counter intuitive results. What seems a 'no-brainer' turns out to have a dramatically negative impact.

Sarah Krasley, sustainable manufacturing manager at Autodesk, says: "It is a vexing issue for many engineers who are trying to do the right thing to improve the environmental footprint of their products. They might use different materials or design in a different way but when you look at it from a whole systems perspective it is not quite as good as hoped."

Examples of good intentions going wrong can be seen throughout industry. A high-profile example was NASA, which decided to replace a lead of solder with a tin solder. The change resulted in a satellite not performing as well. It had to be decommissioned and dealt with. The result was hundreds of thousands of dollars and tons waste.

Legislation is also not always the best guide, or driver, either and can lead to a very narrow view. While a one set of criteria might be achieved, it is often done at the expense of others. Examples of this can be seen in the automotive industry which is reducing fuel consumption as a result of targets set around tailpipe emissions measured in g/km of CO2. Many adverts now quote this figure.

As a result, hybrid motors and alternative materials are being sort. Aluminium is a popular choice for making car structures lighter but it is much more energy intensive to refine from virgin ores compared to steel. And that is the problem. The impact of manufacture and disposal can significantly offset any reduced tailpipe emissions. As a result, last year the World Steel Association called for a shift in the target that is driving automotive design from tailpipe emission to a LCA approach to give a truer picture of a vehicles environmental impact.

Counting the cost
"Even if you are not looking at this from an altruistic perspective, from a cost perspective you have got to deal with this stuff," says Krasley. "If you don't have a proactive strategy for better finding materials that are not impactful from a resource perspective, your cost of doing business is just going to go up."

Many software vendors are partnering with material database companies to help bring this information forward. Autodesk has partnered with Granta Design to facilitate the use of a 'Materials Dashboard' to allow the comparison of a baseline with numerous others and see in graphical format the change in embedded energy, CO2, water and cost. This is about giving engineers information so they can experiment with different materials, simulate their performance and make their own tradeoffs earlier in the design process.

Sustainable design is much broader than having good processes and material selection. A product has impacts in a lot of different ways and these are usually described in five or six stages. The first is material extraction. That is the impact of the raw material being removed from the ground.

The next stage is material manufacturing. It might be the metal ingots and all the processing and machining; it could be epoxy resins and carbon fibres and the processes around those; or the refinement of oil and chemical mixing of a plastic compound.

Asheen Phansey, sustainability product manager at Solidworks, says: "All this happens before a designer even creates anything in the CAD department. If you extrude just a simple block of aluminium and you take that to production it has got that entire environmental burden associated with it already."

Solidworks has partnered with PE International to also offer a materials 'dashboard' that shows the embedded carbon, energy, air and water in separate pie charts that break down the embodiment in to material, transport and use, manufacturing, and end of life. This shows comparison with a baseline and allows users to run simulations with different materials to assesss if the mechanical properties are good enough. It also allows for regions of material production to be included, so Chinese steel might have used energy from coal fired power stations, which will be reflected on the dashboard.

"What we are trying to do is predictively estimate all of these impacts right in the design environment so the engineer can see the effect of a design decision," says Phansey. "For example, we want users to be able to realise that something might affect the end of life impact of a product and be able to change the design before it even gets to the manufacturing floor."

In short, sustainable design borrows heavily from lifecycle assessment and looks to bring the process forward right to the early stages of design. While this has always been desirable, it is only until recently that enabling tools such as those coming from Autodesk and Solidworks, have become more assessable and available.

These are not meant as replacement for full LCA which will still remain. What these are doing is allowing analysis at the frontend; to act almost as filters and guidance. Like early FEA in the design process, it is there to steer engineers, highlight what is working and what is not. It is about having information about all the hidden aspects that go in to creating, using and disposing of a product. Ultimately, it is about efficiency, being more profitable with less environmental impact.

Phansey concludes: "We want to provide engineers with a tool that makes these things intuitive, to sharpen peoples own sense of how to measure their impact and think about design holistically."

Author
Justin Cunningham

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