Relaciones que entretejen alrededor del producto

During the design stage, prototype cars, are tested and assessed for durability and reliability (Happian-Smith 2001). The broad spectrum of users and disparate operating environments are difficult to predict (respondent E3) (Kleyner and Sandborn 2008), as opposed to heavy machinery, such as earth movers or public transport. One car model (e.g. Ford Fiesta) can be sold worldwide and operate in disparate environments. Thus, development engineers try to simulate or test in these operating environments, from dry deserts to arctic climate, during the product development stage. Some pre-production prototypes are taken to these environments to test whole vehicle capability and performance under such conditions, whilst others are tested in simulation rigs, where such conditions can also be simulated for component assessment. Manufacturers have to ensure consumers and regulators that under any possible weather and driving condition the vehicle will be operational and reliable (Happian-Smith 2001). This is the main reason cars and their components are subject to intensive laboratory and field testing (Kleyner and Sandborn 2008). Testing benchmarks simulate ten years of use under the worst possible conditions, with prototype cars being driven intensively during their development stage but reflecting differences in manufacturers practice ranging from 100,000 km (respondent D1), 150,000 km (respondent E4) and 320,000 km (respondent E2).

Cars are, allegedly, longer-lasting, durable and designed with an optimised lifespan (respondent D3 and E6), around ten years. It is presently possible to extend their lifespan towards twenty years or more (respondent E2 and E6). Some interviewees affirmed that increasing the lifespan of cars by design would be ineffective from the perspective of material use, energy and emissions, however they also assert that cars are already durable enough or that it would be

125 possible to increase their lifespan through a mix between age, mileage (Cooper 2010) and operating environment. Moreover, there are development costs that may hinder the design of longer lifespan cars. For example, vehicle testing would have to be extended in order to develop a more durable car (respondent E2) and corrosion protection was seen as the main area for increased testing (E1, E2, E4). This would, in turn, increase the time it takes to develop, validate and produce a car from concept to market (E4).

Another impact of designing for longevity, under the current automotive paradigm, would be a potential increase in material use. Creating more durable, thus robust structures and components, would increase material and energy use, irrespective of the adoption of lightweight materials such as aluminium and carbon-fibre instead of steel (E3, E4). This would directly increase vehicle weight, which in turn may create a ‘vicious circle’ of more powerful engines, brakes, radiators and water pumps, potentially hindering CO₂ emission targets (D1, E3). However, such a longer-lifespan design alternative, could potentially be offset if associated with throughput reduction. In other words, the impact per vehicle produced could be higher, but a substantial a reduction of manufactured vehicles could reduce the overall material and energy usage. Sharing cars during the use-stage could further reduce the number of cars needed, despite being slightly more polluting, reducing negative environmental impact across their lifetime.

Longevity would be another specification to add at the design stage (respondent E3). Designers and engineers would, within project budget, need to choose appropriate materials, manufacturing processes and technology to meet longevity specifications (respondent E3). Nonetheless, when starting a project for a new generation product, manufacturers try to minimise material, due to cost, but also tailpipe emissions, due to regulations. Designers aim to use as little material as possible (respondents D1, D4, E1, E4 and E6), although enough to meet performance and safety requirements, whilst mitigating emissions.

There is a disparity in the number of miles cars are tested during product development stage in different manufacturers. Each company has different standards for testing longevity. Another divergence was the reaction to increasing longevity through design. Some interviewees rejected the idea, arguing that this would increase weight and emissions. Others maintained that cars can be designed to be longer lasting with minimal effort. Increasing overall weight and emissions

126 would potentially be beneficial if production numbers decreased together with overall emissions from production, consumption and EoL management accounted for. Improved corrosion protection could reduce structural failure and increase the potential lifetime enabling an opportunity for the industry to gain experience in this area.

4.1.7 Maintenance and Reparability

One interviewee claimed that increasing maintenance frequency potentially contribute to a car’s durability (respondent E2). Increasing maintenance frequency could increase material and energy usage if, for example, service maintenance increases too. Another design requirement during product development is the time it takes to service a passenger car, including labour time, tooling requirements and ergonomics (respondent E3). Servicing a car involves material and energy use that may not be environmental desirable.

Cars, due to safety and relative value, are one of the few household goods with recommended regular maintenance and compulsory safety checks. The car industry has gained extensive experience in both. However, later in the vehicle’s life, when costly maintenance is needed on parts that take longer to wear (e.g. clutch and bearings), some design compromises surface (respondent E4). These compromises may be a result of design specifications, safety requirements, regulations, technology applied, repair costs and parts availability. In Japan, for example, cars are often discarded at the end of seven years due to high maintenance costs, stricter safety checks and expensive insurance premiums (Nieuwenhuis 2008).