the economic life cycle Stephen Evans and Tim McAloone Dr. Stephen Evans' industrial career span the design to manufacturing interface in companies manufacturing radar, avionics, software and ejection seats. He leads groups researching into Environmentally Conscious Design and Concurrent Engineering at the CIM Institute, Cranfield University. Tim McAloone is conducting research for a PhD. into the inclusion of environmental criteria in the design of electrical/electronic products. Based at The CIM Institute, Cranfield University and involved with an EPSRC funded project entitled DEEDS, Tim works with companies researching environmental decision making. Incorporating environmentally sound decisions into product design is a new challenge for designers. Competent designers are practised in cost-based decision-making in order to produce high quality products that are on-time to market and cost effective 1, 2 . But until recently they have not had cause to consider the environmental consequences of their products. If environmental concerns are to be successfully brought into the product design process they must be quick and simple to incorporate. But they are unlikely to be adopted if the method of embodiment of environmental concerns into design is alien to the designer or cumbersome to carry out. The concept of Life-Cycle Economics (LCE) is explored here in terms of how it can be used to aid designers to choose where to begin reducing the environmental impact of a product, whilst still retaining a sound economical balance during design. The mechanism for carrying out the analysis is described. The views expressed are those arrived at as a result of consultancy work with manufacturing companies. Particular reference is made of a case study involving a electrical/electronic domestic appliance manufacturer (which has had to remain anonymous to respect the company's wish for confidentiality). The work undertaken involved extensive face-to-face interviews with key people involved throughout the design and manufacturing processes. This also involved the company's existing 're-manufacturing' department. The findings from the study were then used in the application of LCE to assess the negative environmental impact of a product. Recommendations of how the negative environmental impact of the product could be reduced, whilst also reducing its production and in-service costs and increasing its profitability at 'end-of-life'. Why incorporate environmental considerations into design? Whatever the drivers for the environmental improvement of products (be they for increased profit, to meet new legislation, due to consumer pressure, or competition) design changes are inevitable. The early stages of the design process give the most opportunity for this change - during the first 20 per cent of the design process 80 per cent or more of manufacturing costs and product attributes are decided 3, 4. Although it is only a relatively short period of activity (compared to the whole life of a product) the impact of the product design stage is considerable. As well as the majority of manufacturing costs being fixed during design the environmental 'performance' of a product is also determined. If we are to attempt to reduce the negative environmental impact of a product ('during manufacture', 'in-use', and at 'end-of-life'), we must look to the design process as being the catalyst for change 5. When considering the effects of a product on the environment the designer must assess the whole product life-cycle. Formalised design models allow the designer to do this, with some element of success, but very few existing design models actually go beyond the stage where the product is passed onto the customer. Thus information that is vital in building up a whole picture of the product is lost when it leaves the factory. There are very few companies who are in the privileged position to have a facility for taking back old products. Those that do can at least fill in another part of the whole-life picture for the product. However, even if provided with all this data, today's designer has neither the time nor the knowledge to manipulate it into a usable form. Whilst we need to be long-term in our efforts to strive for sustainable development, we also need some short-term environmental solutions that can be easily implemented, such as a 'five minute environmental design tool'. This would help the busy designer to incorporate environmental considerations into the design process without having to sacrifice a great deal of design time. Such tools would give designers the motivation to adapt to being more environmentally considerate because they would be simple, effective and very supportive. Thereby the designer would gain an interest in becoming a steward of the world's resources, rather than a conqueror. A counter-argument is that 'five minute' environmental design tools give five minute solutions; and this may be true - in isolation. When gathered together into the practice of Life-Cycle Design (LCD) however, such solutions can build up into a powerful tool-set of environmental design enablers. Having recognised then that design is an opportune time to study the environmental affects on a product, we must also keep in mind the strict time constraints and lack of knowledge when forming a solution. Let us then explore the difference between two possible approaches. Some approaches to incorporating environmental considerations into design approach 1: adopt existing methods Using Life Cycle Analysis (LCA) as a tool involves a process by which a product is assessed in terms of its toxicological content and balance by analysing the inventory of materials that accompanies a product. The problems with LCA are well documented 6, 7, 8. Firstly LCA is a very perfectionistic and time-consuming activity. It can very quickly result in an extended study 'modelling the earth'. The way in which to alleviate the problem of too much information is to draw tight system boundaries for the LCA. The problem here is that from one organisation to the next there is no agreement on where to set these boundaries. Finally, when all of the analysis has been carried out, the results are in a language that is alien to anyone except the learned toxicologist. No common environmental 'currency' exists to deal with the results of LCA. approach 2: experiment with new methods We have already discussed that competent designers are familiar with cost. We also appreciate that the most attractive tools to a designer are of the 'quick-to-implement' sort. Consequently, if we knew the comparative environmental impacts of certain materials/components choices, this would be of immeasurable value. Unfortunately such 'off the shelf' solutions are a long way away. Given our inability to meet all of these criteria, this would be an attempt to take a whole life economic view (to provide a quick method of aiding the designer) in order to see whether it is possible to engage the designer's interest in 'whole-life' thinking and hence environmentally conscious design. life cycle design (LCD) Life-Cycle Design (LCD) is a process that allows the designer to pragmatically consider each stage of a product's life during design in order to fulfil the demands of customers and of society. LCD is a process that runs continuously through the whole process of product development and considers the whole product life, from the recognition of a need, through design/development, production, distribution, usage, and disposal/recycling 9 ,10 ,11. Different solutions must be evaluated in each of these product development stages, based on criteria such as:
Life cycle economics Having carried out life cycle design techniques a list of environmental concerns can be drawn up for a product. Traditionally organisations have taken the view that being green will cost them money. There are many examples of environmental horror stories when companies have been reactive to an environmental disaster 12 ,13. However, by taking a pro-active approach, it may be found that money is saved or even made in this process. Unless there is a threat of legislation or prosecution, or unless the cost can be balanced with a benefit, no organisation is going to be pro-active to environmental considerations. Thus one way in which to tackle the environmental concerns identified is to consider the economics of each concern. By taking an economic life-cycle view of a product design, each stage of the product's life is assessed in terms of cost. At each stage of this life-cycle choices have to be made. For example: should a product be made from a cheap material that is easy to recycle, but is not durable; or from an expensive material that will last longer, but is impossible to recycle? Such dilemmas will certainly be encountered by every person in the next generation of environmentally aware designers. The problem with such dilemmas is that the answer is never close to hand. Companies cannot afford to wait for the perfect solution to appear - indeed it may never do so. By looking at such 'stalemate' situations, however, the cost implications of either choice can be estimated (landfill, materials prices, maintenance, volume of material required etc.) and the most cost-effective and robust solution chosen. Case note - life cycle profitability study A project carried out with a manufacturer of electrical/electronic domestic appliances allowed for life-cycle profitability considerations to be applied, and to evaluate the benefits of this approach. A product was chosen and assessed in terms of its whole life-cycle; from design, through manufacture, distribution, in-use, disposal, disassembly and re-use. The product assessed was methodically disassembled - in order to be able to comment on the product design and to establish a disassembly precedence. Information was collected from all aspects of the business, in relation to specific data required about the product at each stage of its life-cycle. Further data, external to the product (scrap material values, landfill costs, etc.), were collected from a number of sources in order to assess the impact of making any changes to the life-cycle of the product. By considering the whole life of the product it became apparent that an enormous amount of data was available from the various factions of the business which would go towards building up an economic model of the product. It was therefore sensible to handle these data by means of a computer simulation model, comprising four main components:
Having collected all of the data necessary to consider the whole life of the product, a full set of 'what-if' criteria (which were produced as a result of carrying out an LCD exercise in the company) were applied to the model. The criteria chosen for this case study were as follows:
Taking one criterion as an example - disposal costs - a typical question and answer could be determined by the model: question "What if there was a landfill levy imposed on all end-of-life (EOL) electrical electronic goods of £X?" answer short term From the case study a landfill levy would have many implications. Presently some EOL and damaged products are returned to a refurbishment plant where low function items can be re-used in the service sector of the business, and high value items can be extracted. The implications of a landfill levy would be that this side of the business may grow beyond recognition, to divert EOL products from going to landfill and incurring cost. Instead, a logistics network would have to be capable of returning many EOL machines from consumers' homes to the refurbishment facility. So as well as being logistics and operational costs, there would be opportunities for revenue from EOL machines and also avoidance of the cost of a landfill levy. long term By the consideration of 'Design for Disassembly and Recycling' (DFDR), 'Design for Serviceability' (DFS), upgradeable designs etc. in the design process, the product would be more robust to changes in disposal costs and would thus be better prepared for any eventualities. (This example is apt in the light of the recently introduced UK landfill levy 14.) As can be seen in the above example, considering any variable in a life-cycle economic manner, (such as landfill costs,) affects many parts of the business and raises many strategic issues. By a method of mathematical analysis 15, the chosen criteria for the whole product (disposal costs, disassembly methods etc.) could be ranked in terms of their importance. The ultimate aim of ranking concerns in this manner is not necessarily to share out the environmental risk areas equally across all concerns, so much as to act as an indicator to which concerns to give priority. Priority is given depending on the individual company's strategy. Lessons learned from the case study The findings from the study provided a start-point: more questions were raised than there were answers. The next stage in the process would be to examine these questions in the design process and begin to plan for more robust product designs. By analysing environmental concerns from an economic point of view, much support and information is available to rank the concerns of the organisation. lessons learned about 'design for disassembly' Considering a product at end-of-life and assuming that it would be disassembled for valuation reasons, the disassembly process could be modelled. A plot was drawn of 'disassembly cost' versus 'value achieved' for the various components and materials. By placing a high value component in two different locations in the product design, the following two plots were could be projected. As can be seen from figure 01, plot 'A' accrues revenue very early on in the disassembly process (when the high value component was placed close to hand in the product), whereas plot 'B' would require much more time and thus cost to achieve the same revenue. Applied to more complex products with many high value items, this exercise could prove invaluable to the designer. So this life-cycle economic approach ensures that any ecological solutions are economically viable. Much emphasis was put on the skills of the designer in assessing the results the study, but the obvious benefits of the method itself as a strategic decision-making tool should not be ignored. Conclusions By carrying out existing practices, such as DFD and DFR, many product designs have been greatly improved over the years. Designers are now beginning to think in 'whole-life' terms, as a result of being exposed to multi-disciplined design teams, and by experiencing their organisation's adaption to taking back their products at EOL. Perhaps now is the time to re-visit these products and assess them from a whole life point-of-view; new issues may be raised that were not previously considered. It is not expected that the designer will suddenly become an expert in environmental issues. But it is necessary to consider ways of guiding designers - towards choosing the right environmental solution by using their expertise. As competent designers are practised in cost-based design, by considering the whole product life-cycle from a financial viewpoint, they can influence the following:
The above consequences are often achieved without having to dramatically alter the mind-set of designers. Having said this, what this exercise has been effective in delivering is an injection of 'whole product life issues' to the designer. In turn, design teams are encouraged to go out and find out information from other departments. Previously this information has had only slight chemical/environmental impact. Used by one design team, this method has ensured that each stage of the product's life is considered early on in design. This enables suitable planning for any 'in-use' or 'end-of-life' costs that may, in the future, become the responsibility of the manufacturer. By ensuring that ecologically sound solutions are economically viable for the organisation, much confidence can be gained in the practice of environmentally conscious design, so that the 'paradigm shift' from being conquerors to becoming stewards of the world's resources 16 can be realised. references Perks R., Sheldon, D. & Bush S. Whole Life Cost, Discussion Paper at
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