International journal of sustainable manufacturing

58 Int. J. Sustainable Manufacturing, Vol. 1, Nos. 1/2, 2008

Copyright © 2008 Inderscience Enterprises Ltd.

Approaches to sustainable manufacturing

G. Seliger Department of Assembly Technology and Factory Management, Institute for Machine Tools and Factory Management, Technical University of Berlin, Berlin, Germany E-mail: [email protected]

H-J. Kim* Department of Mechanical Engineering, College of Engineering, University of Michigan, Ann Arbor, USA E-mail: [email protected] *Corresponding author

S. Kernbaum and M. Zettl Department of Assembly Technology and Factory Management, Institute for Machine Tools and Factory Management, Technical University of Berlin, Berlin, Germany E-mail: [email protected] E-mail: [email protected]

Abstract: Topics on sustainable manufacturing, use, environmentally friendly treatment and resource recovery are currently very important issues for governments and industries worldwide. Environmental regulations for technical products currently focus on recycling ratios and prohibition of toxic materials. The concept of creating more use-productivity with less resource consumption has considerable potential to a sustainable society. Hence, the objective of this paper is to identify a research and development plan for sustainable manufacturing focusing on enhancing use-productivity. Core research fields are identified, and finally their technology road maps are developed.

Keywords: sustainable manufacturing; use-productivity.

Reference to this paper should be made as follows: Seliger, G., Kim, H-J., Kernbaum, S. and Zettl, M. (2008) ‘Approaches to sustainable manufacturing’,Int. J. Sustainable Manufacturing, Vol. 1, Nos. 1/2, pp.58–77.

Biographical notes: Günther Seliger studied Industrial Engineering at the TU Berlin. He was Research Assistant and Chief Engineer at the Institute for Machine Tools and Factory Management at the TU Berlin and earned a doctorate at the Department of Professor Günter Spur. He has been Professor at TU Berlin since 1988 and represents the Department for Assembly Technology and Factory Management at the Faculty 5 Transport and Machine Systems. Furthermore, he is the speaker of DFG – Collaborative Research Center 281 ‘Disassembly Factories’.

Approaches to sustainable manufacturing 59

Hyung-Ju Kim studied at Precision Mechanical Engineering (Bachelor) and Industrial Engineering (Master) in Pusan National University, Pusan, Korea. Then he earned a doctorate at the Institute for Machine Tools and Factory Management (IWF) at the Technical University Berlin. After the two years job as senior researcher at the Korea Institute of Science and Technology Europe (KIST Europe), Saarbrücken, Germany, he works currently as postdoctoral research fellow at the Department of Mechanical Engineering, University of Michigan, Ann Arbor, USA. His research areas are disassembly, disassembly control and remanufacturing.

Sebastian Kernbaum studied Mechanical Engineering at Technical University Berlin from 1998 to 2003. After being a visiting researcher in the University of New South Wales, Sydney and the University of Southern California he became a Research Engineer at the Institute for Machine Tools and Factory Management at Technical University Berlin in 2004. His research areas are in the area of life cycle engineering especially in the development of planning and evaluation methods. The research is based on the Collaborative Research Center 281 ‘Disassembly Factories for the Recovery of Resources in Product and Material Cycles’ which was completed at the end of 2006.

Marco Zettl studied from 1996 to 2003 Mechanical Engineering at the Berlin Technical University (TUB). After graduation in February 2003, he worked for six months at the University of Michigan, Ann Arbor, USA. Since November 2003, he is Research Engineer at the Department Assembly Technology and Factory Management at TUB in the field product development with focus on modularity. His work is based on the Collaborative Research Center 281 ‘Disassembly Factories for the Recovery of Resources in Product and Material Cycles’, which was completed at the end of 2006.

1 Introduction

Humankind is confronted with global challenges related to economy, ecology and socio-policy, e.g., movement of labour, global warming, and population increase. Since emerging countries, e.g., China and India, counting for about two-fifths of present global population, are demanding the life-style of industrialised countries, the resources and the ecosystem of the globe come under increased pressure. Engineering is confronted with the challenge of paradigm change to provide increasing standard of living without exceeding ecological limits. Present products and processes express the life-style of the developed Western World counting for less than one-fifth of the global population. Six billion people of the globe cannot live on existing western standards without exceeding ecological limits. Technology has to be adapted according to criteria of sustainability. It is estimated that because of human resources consumption, by the end of the 21st century, the global average temperature will have increased between 2°C and 7°C when compared with the actual values.

It becomes apparent that industrialised as well as emerging countries have to face these challenges together to conserve the resources and the ecosystem of the planet for future generations. On international political level, first steps in this direction of sustainability are global treaties as well as regional regulations and incentive systems. The Kyoto Protocol to the United Nations Framework Convention on Climate Change negotiated in 1997 is an example for such a global treaty. Since September 2005,

60 G. Seliger et al.

a total of 156 countries agreed on the reduction of their carbon dioxide emissions and five other greenhouse gases. Regional legislations are, for example, the European Union directives on Waste of Electric and Electronic Equipment (WEEE) and End-of-Life Vehicle (ELV). Often these activities are addressing only ecological aspects without taking economics into account. Global challenges can only be met by simultaneously considering social, economical, ecological, and technological criteria.

In this context, the principle of sustainability as a mission statement for development moves in the spot of attention. A reasonable definition of sustainability has been introduced by the World Commission on Environment and Development in the so-called Brundtland-Report ‘Our Common Future’ in 1987. Based on this definition, sustainable development is defined as a holistic approach harmonising ecological, economical and socio-political needs with respect to the superior objective of enhancing human living standards. The availability of natural resources and the task of conserving the ecosystems have to be considered so that future generations have the possibility to meet their own needs. However, this goal cannot be achieved with current resource productivity and current trifling with the ecosystem without bursting the limits of the globe (Figure 1) (Seliger, 2004).

Sustainability in engineering can be defined as the application of scientific and technical knowledge to satisfy human needs in different societal frames without compromising the ability of future generations to meet their own needs. To achieve this goal, scientists and engineers cooperate in international and multidisciplinary groups and organisations. They utilise imagination, judgement and take initiative to apply science, technologies and practical experience to shape competitive processes and products. Management guides the creation, application and evaluation of science, technology, processes, and products, as well as the dissemination of knowledge.

Figure 1 Approach to increase the global standard of living without bursting the limitsof the globe

Source: Seliger (2004)

Challenges of sustainability in engineering are illustrated in Figure 2, whereby human needs are represented as the MASLOW pyramid spanning all societies in the world (Maslow, 1999). The different coloured columns between the human needs and the available resources describe the dissimilarity of conditions of the global society. Engineering challenges are design of products and processes with improved usefulness and less environmental harm. Technology interpreted as science systematically exploited for purposes offers huge potentials to contribute. Technology enables for processes transforming natural resources into products to meet human needs. The interaction between research and education imposes dynamics on how creative solutions are


developed for relevant tasks. Owing to new means of transport and communication, knowledge and value creation is no longer limited to niches of wealth but more and more accessible by everyone, everywhere at anytime. These dynamics must be mastered by management considering chances for cooperation and risks of competition. Different societal frames with different value systems considering economical, ecological and socio-political issues in different regions of the globe have to be taken into account (Seliger, 2004).

Figure 2 Engineering perspectives in sustainability


Currently, only few companies, governments, organisations and institutions are considering and incorporating aspects of sustainability. Several best practice examples regarding ecoefficient and sustainable products are promoted by predominantly large global-acting companies (NN, 2007a). However, the potential of sustainability in engineering is not exploited yet. There is still a lack of scientific basic principles, methods, procedures and tools for planning, development, adduction, and utilisation.

2 Approaches in sustainable manufacturing

From the 1980s, activities in sustainable manufacturing started to focus on waste reduction in production, so-called cleaner production. The activities were extended to the reduction of resources and energy use in production. After this, the paradigm for sustainable manufacturing has been changed from production-oriented to product–oriented one. The changed paradigm is realised by the Integrated Product Policy (IPP). The product-oriented approaches are, on the one hand, activities for reduction of resources and energy in a product. On the other hand, there are activities for reduction of toxic materials, and development and use of renewable materials. In addition, the term ‘cycle economy’ was introduced (NN, 2003a). Until now, the cycle economy approach has focused on material recycling, which has had some successes in the cycle economy market. However, pure economic success is still difficult to achieve. Even the consolidated environmental regulations such as ELV (NN, 2000) and WEEE (NN, 2003b) make demands on pretreatment of toxic materials, including components, reuse and remanufacturing of components or products for the profitability of their activities.

Until now, the scientific approaches have neglected to enhance sustainability in the use phase and have also focused on the design for environmental and material level


recycling. However, sustainable manufacturing for the next generation should focus on enhancing use-productivity in the total product life cycle. For enhancing use-productivity, there are the three strategies illustrated in Figure 3:

• Implementation of Innovative Technologies is a strategy focusing on the evaluation and implementation of feasible and innovative technologies for resource-saving applications.

• Improving the Use-Intensity is a strategy to improve use-productivity by increasing the utilisation ratio of a product. This strategy intends to maximise productivity per resource input.

• Extension of Product Life Span is a strategy focusing on extending the time between cradle and grave of a product by expanding the use phase and realising multiple use phases. The resource consumption for production and disposal of products shall be reduced with this strategy.

Figure 3 Framework for sustainable manufacturing based on Kim et al. (2006)

2.1 Implementation of innovative technologies

The objective of this strategy is the evaluation and implementation of innovative technologies, which are used for resource-saving applications. Hereby implementation means both, application and implementation. Innovative technologies can be applied to improve product and process design, e.g., modularity and lightweight construction. Moreover, innovative technologies can be implemented in products for resource-saving applications. Innovative technologies are, e.g., fuel cell, photovoltaic and laser technology. Vital element of this strategy is the evaluation of technology according to sustainable manufacturing.

A best practice example for the application and implementation of innovative technologies is the automobile Loremo (Figure 4). Loremo is an acronym for Low Resistance Mobile. The automobile is powered by a turbo-charged combustion engine and consumes 1.5 l diesel fuel per 100 km. The low fuel consumption results mainly from


the reduction of the weight and the air resistance. A new Loremo variant shall be equipped with a hybrid power technology to improve performance and reduce diesel fuel consumption. The Loremo AG is an innovative start-up company located in Munich, Germany. The start of mass production is planned for 2009 (NN, 2007b).

Figure 4 Automobile concept of the Loremo

Source: NN (2007)

The Schmitz Cargobull AG is a company mainly producing trailer for freight transport on the road. Its headquarters is located in Horstmar, Germany. Schmitz Cargobull had an annual turnover of about 1.3 billion Euros in 2005–2006. The company is one of the biggest trailer manufacturers worldwide. By applying modularity and standardisation on their product spectrum, the efficiency of product development and production processes has been improved. More product variants can be realised with a higher quality by reduced development time, reduced component variants, and more efficient production processes (Naber, 2006).

2.2 Improving the use-intensity of products

Improving the Use-Intensity of products is regarded as the use phase in the product life cycle. The objective of this strategy is to increase the utilisation ratio of a product or of its components. Two approaches have been identified to achieve this goal. First, by applying a business model, where the use of a product and not the product itself is the object of the companies’ business. This service-oriented approach is also called selling use instead of selling the product (Seliger et al., 2004). The second approach is related to a more sustainable use of a product by the user.

2.2.1 Service-oriented business model

In a service-oriented business model, the service provider offers the functionality of the product to the customer without passing the product out of his possession. He is responsible for the accessibility of the required utilisation and the treatment of the equipment over the whole lifetime. The service provider manages the costs of investment, transport, operation, maintenance and disposal. Consequently, the customers only pay for the use that they obtain by the product and not the product itself (Seliger, 2000). The service provider is responsible for the availability of the use at the right place and time in adequate quality. Therefore, he/she needs system-accompanying quality management, information and communication systems to guarantee product pursuit and product access. Leasing-, rent- and service-contracts regulate the responsibilities between customer and service provider.


Requirements on products for the service-oriented business model are modularity, integrability, customisation, convertibility as well as diagnosability to support customer-driven adaptability (Seliger et al., 1997). The implementation of these properties in a high level increases the applicability and the availability of a product. Requirements of the service process are higher idle capacity costs of a product when compared with the extra costs to be paid for logistics and information management (Seliger et al., 1999). Logistics include all necessary processes to provide the demanded use at the right place and time in adequate quality (Fleig, 2000).

The annual after sales market for the automobile industry has over 100 billion Euro market turnover and the market has 20 billion Euro turnovers for leasing and renting service alone. On the other hand, approaches by the machine tools industry amount to 5 billion Euros for domestic production and import in Germany. Three hundred and fifty million Euros are acquired by maintenance and remanufacturing services. Figure 5 exemplarily shows the application of approaches by the investment goods industry in Germany. More than 58% of the companies have at least one service program of the three listed in Figure 5: modernisation and retrofitting; renting and leasing; as well as reverse logistics and disposal. More than 8% of companies operate all three service programs (Fleig, 2000).

Figure 5 Sustainable production and service in Germany

MVS Zeppelin GmbH is the largest provider of full service leasing of construction machines in the EU. The company possesses 1200 employees. Their service includes total maintenance and meeting clients’ product requirements as well as extension of product life span by remanufacturing and upgrading (NN, 2007c). Its main field of business is the Full Service Hiring of constructional and agricultural machines, which the MVS repairs and services itself. Instead of investing in its own machine park, the customer hires the appropriate equipment from MVS as and when it is needed, which intensifies the use of the machines and eliminates the long periods of inactivity associated with ‘normal’ use. This is an exemplary instance of ‘sale of use’.

Mercedes Benz CharterWay GmbH is involved in the buying, leasing and renting of commercial vehicles. Their service motto is full service ‘ready to use’. The firm now has 7000 clients, 65,000 vehicles and 400 million € turnover in 2005 (NN, 2007d).


The core competence of the company is service providing for its commercial vehicles regarding repair inspection, and maintenance service. Therefore, their customers do not need to buy the product and also they do not need to worry about such maintenance issues. They only buy the services of the company. Additionally, Mercedes Benz CharterWay GmbH operates a systematic closed network with repair service, second-hand vehicle and remanufacturing service providers. The company also has activities about feedback on component wear behaviour and product life cycle information with its parent company (Figure 6).

Figure 6 Examples of a sustainable product service system

Source: NN (2007c, 2007d)

2.2.2 Distributed use of products and components

This approach is aiming at increasing the utilisation ratio of products and components by its distributed use in different applications. To the same time functionalities and thus functional carriers of products are substituted. The utilisation ratio is related to a product or component and can be calculated by comparing the standing time with the operation time. For example, if an automobile is used in average for 2.4 h a day, then the utilisation ratio is 10%. Two possibilities of increasing the utilisation ratio have been identified: Multiple use of products’ functionality in applications not necessarily offering but providing the respective functionality. Hereby, the whole product and also components or modules can be used in different applications, e.g., a stand-alone MP3 player used in combination with a car radio and a home entertainment system.

Use of flexible and reconfigurable products for various differing applications. Flexible products incorporate the needed functionality for defined applications, e.g., mobile telephone. A reconfigurable product can be adapted to different applications by adding, removing, and changing functionality modules, respectively, e.g., modular disassembly toolkit (Seliger et al., 1999).

The decision for one of these possibilities has to be carried out in the product development process by evaluating the economical, ecological, and technological feasibility according to the type of the respective product. Hereby, strategic aspects as well as customer requirements have to be considered. Product-related requirements are modularity, product and component compatibility, standardisation of components and interfaces, and high product and component quality.

Nokia is the world’s largest manufacturer of mobile phones. The market share rose to 36% in the third quarter of the year 2006. In the same year, Nokia employed 67,693


people, in the business group mobile phones 3682 people (NN, 2007e). Today’s mobile phones substitute products such as MP3 player, radio, navigation system, data storage, photo and video camera for basic applications. Originally, the mobile phone was used mainly for phone calls and storing phone numbers. The miniaturisation in the electronic industry leads to an integration of more functionality in electronic products. However, the functionality of mobile phones is often expanded by external modules using Bluetooth as module interface, e.g., external GPS device. The company that can offer the best composition of additional functionality in a high quality is more successful on the market.

The mobile phone is a device accompanying the user to almost every place. The integration of more functionality in a mobile phone has a positive effect on the resource productivity in case other products or product modules can be substituted. For example, an integrated device for mobile television could substitute the television receiver at home. Favourite channels and personal settings could be stored on the personal mobile device. Especially in the electronic industry, such approaches have a high potential to increase the resource productivity. This seems apparent, since the manufacturing of electronic devices consumes plenty of resources (Figure 7) (Basdere, 2004).

Figure 7 Primary Energy Demand of EEE along the product life cycle

Source: Basdere (2004)

2.3 Extension of product life span

Extension of the product life span can be achieved, on the one hand, by expanding the use phase and, on the other hand, by the realisation of multiple use phases. Maintenance and modification are means of expanding the use phase of a product. A balanced strategy of preventive maintenance preserves or increases the residual value of a product (Seliger, 2000). Modification is the adaptation of a product during the use phase due to changed functional requirements. Kinds of adaptation are up- and downgrading, enlargement and reduction as well as rearrangement and modernisation. Modification and adaptation require disassembly and reassembly processes (Müller, 2001). Additional processes are cleaning, testing, component supply and removal.

Multiple use phases are realised by remanufacturing and adaptation. Nasr defines remanufacturing as reviving a product to a like-new condition in terms of performance and durability by disassembling, cleaning, inspecting, repairing, replacing, and


reassembling the components of a product (Nasr, 2004). Adaptation processes are applied to react on changed functional requirements of the next use phase in the respective market. Requirements to products for this strategy are modularity, integrability, customisation, convertibility, and diagnosability supporting efficient processes of preventive maintenance and modification as well as remanufacturing and adaptation.

The Caterpillar Remanufacturing Service has 12 remanufacturing factories all over the world. Its European remanufacturing factory in Shrewsbury, UK, is the largest European remanufacturing factory. Their remanufactured product spectrum ranges from a 1 kg water pump up to 1200 PS military tank engines. 61% of engines and components are directly remanufactured. They say their remanufacturing process saves 85% of the energy in comparison with original production, and 25% of the remaining material is recycled. Figure 8 shows before and after views for remanufacturing of a commercial vehicle engine (Hoefling, 2005).

Figure 8 Before and after the remanufacturing of a vehicle engine block

Source: Hoefling (2005)

The Flection Group is one of the largest ‘Re-Use of Information Technology’ companies in Europe. They have operations in the Netherlands, Germany, Belgium, France and Spain. About 2450 Assets are refurbished and remanufactured per day. The main products are PCs, servers, notebooks, printers, monitors, keyboards and copiers. The company buys end-of-life IT products from several leasing companies and strategic partners like HP, Fujitsu Siemens, Dell and IBM. In 2005, more than 288.000 assets were processed, redeployed and sold worldwide. They had 15 Million revenues in 2005, which is a growth rate of 7.5% (NN, 2007f).

In the following, exemplary case studies enhancing the product life span by efficient adaptation processes will be presented from own research work.

3 Efficient adaptation processes

Allowing multiple use phases of products and components is a major element of the strategy extension of product life span. The environmental impacts caused by production and disposal can be reduced, while the remarketing of remanufactured and adapted products can be profitable business fields. By providing affordable remanufactured products and components in low and medium income regions, the standard of living can be enhanced. Especially EEE products, such as mobile phones and flat screen monitors, have a large impact on the environment because of their large production volumes and often short time scales of technological and stylistic obsolescence.


For efficient remanufacturing and adaptation processes, on the one hand, products have to be designed considering the whole life cycle, starting from the development along their use up to their reuse or disposal. On the other hand, flexible and adaptable tools and production facilities as well as product-accompanying information systems are necessary to provide data about the product status.

3.1 Technological enabler

Product and process-related enabling technologies for efficient adaptation of products and components are modularity and diagnosability. The implementation of these properties in a high level increases the applicability and the availability of a product in multiple usage phases.

3.1.1 Modularity

Modularisation is the key enabler for adaptability and reconfigurability of a product allowing quick disassembly and reassembly of modules. Aspects of technological stability, upgradeability, serviceability and technical lifetime (Kimura and Satoru, 2002) have to be considered while developing the modular structure of the product.

The objective of modularisation is to achieve a high degree of physical and functional independency of the modules. The physical independency between modules is higher than between components within a module. A vital element of physical independency is the design of disassembly and reassembly suitable module interfaces. Hereby, functions for material, signal and energy flow are integrated in the physical design of the module interface. Module interfaces can be divided into definite, multiple and universal (Basdere et al., 2004). The highest degree of independency is achieved by multiple and universal interfaces that allow an arbitrary exchange of the modules leading to a highly flexible product structure.

The standardisation of module interfaces is significant for the reuse of modules in different product generations and variations. To achieve functional independency of a product, the carriers of functions have to be grouped appropriately. The groupings have to be carried out with respect to different competing goals, which can be described as module drivers (Erixon, 1998). A multicriterion modularisation methodology based on module drivers has been developed and implemented in a software-based module configuration tool called Module Configurator. The Module Configurator supports the complex process of developing modular product architectures (Zettl et al., 2006; Seliger and Zettl, 2007).

3.1.2 Diagnosability

Knowledge about the usage and status of a product allows adaptation in case of physical changes. For instance, in the business model selling use instead of selling products, the use provider is responsible for the continuous failure-free availability of the products functionality. Thus, diagnosability becomes a core competency of the use provider. But also by purchasing the product the availability of knowledge about physical changes is of significance for the user to plan maintenance activities or to decide whether the product or its modules can be reused.


Current existing monitoring systems are based on the recognition of indications of failure (Engel et al., 2000). The main physical values they analyse are force, temperature, current, and magnetic field (Seliger et al., 2003). Life-cycle-accompanying diagnosis requires the identification of use-intensity factors for components and modules of a product (Seliger et al., 2000). The Life Cycle Unit (LCU) enables checking for the deterioration status of components by sensorial devices, for data storage, processing and transferring by microcontroller boards and for initiating maintenance and save disassembly by actuators (Figure 9).

In a collaborative research project between the Center for Intelligent Maintenance Systems (IMS) of the Universities of Cincinnati and Michigan and the Technical University (TU) Berlin, the LCU concept is investigated for the assessment and performance prediction of product condition, in this project a freight train bogie. The goal is to minimise the downtime and extend the utilisation phase of a freight train bogie by monitoring standard components such as shock absorber, braking system and bearings. The developed electronic system is called Embedded Watchdog Agent/Life Cycle Unit (EWA/LCU). The challenge lies in the methodical modular design of hardware and software components of the EWA/LCU and integration of performance assessment and prognostic capabilities within the frame conditions of embedded technology, e.g., restricted power supplies and limited processing power (Buchholz, 2005; Yang et al., 2004).

With the help of the LCU, the permanent access on knowledge about the usage of a product is possible. This allows adaptation of the product in case of capacity and functional changes, and Condition-Based Maintenance (CBM) in case of physical changes.

Figure 9 Principle of EWA/LCU functionality

Source: Buchholz (2005)

The product knowledge is crucial to guarantee the required functionality and to make reuse of products economically feasible. Moreover, the concept of the LCU can be used to collect, store, evaluate and transfer data about economic, environmental and social


aspects of a product to support, e.g., Life Cycle Analysis (LCA), Life Cycle Costing (LCC).

3.2 Applications for processes and products

The application of the technological enabler modularisation and LCU are introduced and discussed on the examples Intelligent Disassembly Tool Kit (DTK) allowing process-sided efficient adaptation and modular Mobile Telephone Kit (MTK) allowing product-sided efficient adaptation. The main characteristics and advantages are highlighted.

3.2.1 Adaptable and Intelligent Disassembly Tool Kit (DTK)

The development of modular tools for manual as well as automated disassembly processes lead to the development of the DTK. The DTK supports easy reconfiguration to different process conditions. The generation of the DTK product structure has been supported by the application of module drivers. Hereby, the module driver adaptation/modification of the product gained the highest importance. The final product structure is characterised by the carrier module, the energy module, the kinematics module, the acting module and the information module.

Acting modules are interacting with the product by transmitting force and torque for loosening and handling operations. Energy modules support, e.g., mechanical energy from converting the energy of the source such as electricity as well as compressed air and oil. Information modules acquire, store, process and transmit process data. Carrier modules are required for the connection between acting, energy, and information modules. They are also a part of the interface between robot and tools allowing automated application as well as labourer and tool for manual application.

Quick and accurate configuration of the DTK is supported by the development of disassembly and reassembly suitable multifunctional interfaces. The DTK interfaces support functions such as physical stability, reconfigurability as well as energy and information flow. According to Basdere et al. (2004), the modules were equipped with definite interfaces allowing accurate configuration of the DTK modules. To enhance the reliability, the DTK has been equipped with LCUs. The LCU monitors the different modules of the DTK to assess, diagnose and predict the behaviour to reduce downtime and idle capacity. This concept enables extended utilisation of products and components (Buchholz and Odry, 2004).

Currently, the system consists of three networked LCUs: The DTK-LCU delivers the status of the DTK, while the two remaining LCUs are integrated into the acting module (Figure 10) and the energy module. The user of the DTK can access the DTK-LCU to get information about the DTK status. In case more detailed information on module level of the DTK is needed, the LCUs in the DTK modules may be accessed independently. The gathered sensor data is used to predict the wear of the DTK components and to deliver accurate facility information to the DTK user.

The data and information is transmitted between the DTK-LCU and the module LCUs using Bluetooth. The uplink between the DTK-LCU and the disassembly system is implemented using Ethernet. Energy is supplied to the independent module LCUs using newly designed pin connectors, that are not affecting the rotational lock systems between the DTK modules.


Figure 10 Dissassembly Toolkit and acting module with attached LCU

Source: Seliger et al. (2005)

3.2.2 Modular Mobile Phone Kit (MMPK)

The Modular Mobile Phone Kit (MMPK) is suitable for efficient maintenance, repair and modification as well as for remanufacturing and adaptation. Additional characterisitcs of the MMPK is the standardisation of the housing components for the form factors candy-bar, slide, and flip phone so that a reconfiguration supported by simple disassembly and reassembly operations of the mobile phone is possible. For the development of the modular product architecture, the multicriterion modularisation methodology is applied. To derive the necessary information for the module drivers, e.g., remanufacturing possibility, scenario management is used. Hereby, the objective is the identification of product requirements for the first and second use phase.

Based on the scenarios, weak points of current mobile phone models, recommendations for the design of the MMPK, and the weights of the module drivers have been derived. Weak points of current mobile phone models are, e.g., low grade of modularisation and standardisation, complex disassembly by snap-fit, glue and screw connections, different assembly and disassembly directions, high costs for cosmetic part supply such as housing and keypad. Recommendations for the design are, e.g., modularisation of the product architecture, standardisation of modules, module interfaces and housing components, disassembly and reassembly suitable module interfaces, and decoupling of the electronic interior components from the housing. The most important module drivers assigned with a high weighting are: core competencies and supply chain, reuse of functional carrier, product innovation, and treatment after the first use phase (Zettl et al., 2006; Seliger and Zettl, 2007).

Based on the best modular product architecture, the alignment of the modules has been generated by considering the different form factors of mobile phones. The final arrangement of the modules is characterised by a platform, the printed circuit board, and 11 modules (Seliger et al., 2006). Besides the modules that are used for the candy-bar


phone, the modules flip mechanism and second display is added for assembling the flip phone. For the slide arrangement, a nearly invisible slide mechanism instead of the flip mechanism and a housing cover need to be subjoined. The slide phone can be opened by sliding the top parts over the lower parts to uncover the numerical keypad (Figure 11).

Figure 11 Virtual Prototype of the Modular Mobile Phone Kit (MMPK)

Source: Seliger et al. (2006)

4 Road map

A considerable gap remains between an increasing public awareness about social, ecological and economical challenges and implementation of sustainability in societal life in different regions of the globe. Every location on earth can be reached physically in less than one day by modern traffic means and immediately by the communication infrastrucutre. Globalisation has become an inevitable condition of life confronting mankind with respective complexity in how to cope with the intertwined social, ecological, economical, and technological challenges. Apparently, industrialised as well as emerging countries have to face these challenges together to conserve the resources and the ecosystem of the planet for future generations. Humankind as a community under the framework of globalisation can only survive if the distribution of wealth is shifted to less concentration, i.e., increasing the equity and if more use is provided by fewer resources, i.e., increasing the use-productivity of resources.

Education, which means both learning and teaching, becomes a coining element of leadership and teamwork in the management of societal institutions owing to an ever-increasing speed of innovation. Modern information and communication technology gives opportunities for an immediate exchange of documents and real-time communication across the globe. Internet-based learning and teaching in internationally assembled teams in cooperation with partner universities has been implemented since a


few years. The framework of sustainability in its Global Thinking/Local Acting scheme offers attractive contents in global engineering education.

Figure 12 derived from NN (2007g) and Wackernagel (2006) specifies relevant aspects of how in the second half of the 20th century parameters, all determined by human activity have developed. About one quarter of earth’s surface accounting for 11.3 billion hectares can be considered as biologically productive area contributing to regeneration of resources. The average amount of biocapacity per capita on earth in 2001 is calculated, dividing the productive area by 6.15 billion people with the result of 1.8 global hectares biocapacity per capita. The diagram curves in Figure 12 show humanity’s total ecological footprint and the respective CO2 portion of it from 1961 to 2001. Since 1985, resource consumption on global level is higher than the ecological capacity. The global population has increased from 3.08 billion in 1961 to 6.15 billion in 2001. Water withdrawals in the same time have increased from 2.04 per year to 3.98,000 km3. Total energy consumption in 2001 is more than seven times the amount in 1961. Remarkable losses have occurred in biodiversity, where the indices since 1970 show an exponential decrease.

Engineering in a broader perspective of potentials and applications is to investigate how to cope with the challenge by increasing the use-productivity of resources. Researchers from engineering science, e.g., manufacturing, medical, transportation, design, information, process, electrical, and civil engineering, integrate their domain-specific knowledge and experiences thus developing methods and tools in management and technology for useful applications in selected processes and products according to criteria of sustainability. An initiative on Sustainability in Engineering could be structured as shown in Figure 13 (Seliger, 2007).

Figure 12 Ecological Footprint

Source: Wackernagel (2006)


Water, energy, construction, health, mobility and manufacturing are domains of engineering activities to be directed along the guidelines of sustainability. Mathematics and knowledge creation by information science provides tools for modelling solutions without expensive realisations. Manufacturing gives methods for realising products in processes. Valuation/assessment helps considering the manifold of sustainability criteria in creating physical artefacts and related services. Education enables for convincing and instructing people about the advantages and methods of sustainability in engineering.

Figure 13 Research areas


The domains and enabling guidelines and tools could be covered in selected aspects of expertise in research and development by the partners of the initiative. Research clusters are described by how partners, coming from their own areas of competence by interdisciplinary approaches, identify areas of mutual interest and contribute in systemic integration to cope with the challenge of sustainability in engineering. It is expected that crossing disciplinary borders and referring to multiple criteria helps improve design and valuation of processes and products.

A common understanding beyond disciplinary borders shall be gained by developing indicators of sustainability. Wealth is created by growth based on environmentally friendly management and technology. Processes and products are adapted to economical, environmental and social conditions in different regions of the globe, thus creating sustainability according to the regional and local conditions in the global network of demand and supply. Representing imagination and experience, the partners apply their common understanding in exemplarily developing physical artefacts and related services of sustainability in and across their respective scientific technical community. Extraction of freshwater and processing wastewater, energy transformation and storage, energy and resource-saving mobility and construction, adaptable equipment for multiple usage phases in agriculture, health, mobility, achieved by respective processes of maintenance and (re)manufacturing represent means of fulfilling elementary human needs by resource-saving technologies. Modelling techniques from mathematics and information science, valuation according to sustainability indicators giving guidelines and tools for design of processes and products, dissemination of knowledge and experiences on


sustainable processes and products by innovative means and tools of education enable for the development of sustainable and innovative means fulfilling human needs (Seliger, 2007).

In a study carried out by the Korea National Cleaner Production Center in cooperation with the Institute for Machine Tools and Factory Management at Technical University Berlin, technological road maps were developed for the 18 technological areas. Figure 14 shows an example of ‘Remanufacturing’ technologies for complex products in the topic field ‘Adaptation’. The road maps are synchronised with the three steps in the strategic development plan:

Phase I: Securing technical background and core technologies (technical background for enhancing use-productivity, selected development of core technologies, securing of international network of sustainable manufacturing).

Phase II: Development and realisation of systems (application of the technologies as real cases, development of systems using the core technologies, reaching global standards in the field of sustainable manufacturing).

Phase III: Facilitating technology transfer and extension of application areas (optimisation of prototypes for mass production, application of technologies into other industries, domestic and international standardisation of sustainable manufacturing).

Figure 14 Technological road map: Adaptation – Remanufacturing of complex products

Source: NN (2003)

Acknowledgements

This contribution presents research results of the Collaborative Research Center 281 ‘Disassembly Factories for the Recovery of Resources in Product and Material Cycles’, financially supported by the Deutsche Forschungsgemeinschaft (DFG) and of the ‘Comprehensive Planning on Infra-Structure Establishment of the Sustainable Manufacturing’, financially supported by the Korean Ministry of Commerce, Industry and Energy (MOCIE).


ReferencesBasdere, B. (2004) Beitrag zur Steigerung der Nutzenproduktivität von Ressourcen durch Anpassen

von Mobiltelefonen, Reihe Berichte aus dem Produktionstechnischen Zentrum Berlin, Berlin. Basdere, B., Friedrich, T. and Härtwig, J-P. (2004) ‘Entwicklung und Realisierung eines Prototyps

einer demontagegerechten Waschmaschine’, DIN-Loseblatt Sammlung Umweltgerechte Produktentwicklung.

Buchholz, A. (2005) Zustandsorientierte Instandhaltung von Standardkomponenten mit Life Cycle Units, Dissertation TU Berlin, Reihe Berichte aus dem Produktionstechnischen Zentrum Berlin, Berlin.

Buchholz, A. and Odry, D. (2004) ‘Enabling a sustainable cycle economy with life cycle units’, Global Conference on Sustainable Product development and Life Cycle Engineering, Berlin, 29 September–1 October, pp.45–50.

Engel, S.J., Gilmartin, B.J., Bongort, K. and Hess, A. (2000) ‘Prognostics, the real issues involved with predicting life remaining’, Proceedings of the IEEE Aerospace Conference Proceedings,Vol. 6, pp.457–469.

Erixon, G. (1998) Modular Function Deployment – A Method for Product Modularization,Stockholm.

Fleig, J. (Ed.) (2000) Zukunftfähige Kreislaufwirtschaft, Schäffer-Poeschel Verlag, Stuttgart. Hoefling, K. (2005) ‘The advanced technologies, services, and profits in the remanufacturing

industry. Best practices from caterpillar’, Proceedings International Conference on Sustainable Manufacturing, 12–15 October, Shanghai, China.

Kim, H-J., Kang, H-Y., Kernbaum, S. and Seliger, G. (2006) ‘Roadmap to sustainable manufacturing by increasing use-productivity’, Proceedings of IV Global Conference on Sustainable Product Development and Life Cycle Engineering, Sao Carlos, 03 October–06 October, S. 0 (CD).

Kimura, F. and Satoru, K. (2002) ‘Life cycle management for improving product service quality’, Proceeding 9th International Seminar on Life Cycle Engineering, Erlangen, Germany, pp.25–31.

Maslow, A.H. (1999) Motivation und Persönlichkeit, Reinbek. Müller, K. (2001) Wege zur Steigerung der Nutzenproduktivität von Ressour-cen, Dissertation TU

Berlin, Reihe Berichte aus dem Produktionstechnischen Zentrum Berlin, Berlin. NN (2000) Directive 2000/53/EC of the European Parlia-ment and of the Council of September 18,

2000 on end-of life vehicles (ELV).NN (2003a) ‘Integrierte produktpolitik (IPP) – auf den ökologischen lebenszyklus-ansatz

aufbauen’, Mitteilung der Kommission an den Rat und das Europäische Parlament,KOM 302, Brüssel 18.6.2003.

NN (2003b) 5.Directive 2002/96/EC of the European Par-liament and of the council on waste electrical and electronic equipment (WEEE) of 27 January.

NN (2007a) http://www.econsense.de, January. NN (2007b) http://www.loremo.com, January. NN (2007c) http://www.mvs-zeppelin.de, January. NN (2007d) http://www.mercedes-benz.de/content/germany/mpc/mpc_germany_ website/de/

home_mpc /trucks/ home/services/charterway/ueber_uns.html, January. NN (2007e) http://www.nokia.com/nokia/0,8764,36094,00.html, January. NN (2007f) http://www.flection.com, January. NN (2007g) www.footprintnetwork.org, January. Naber, T. (2006) ‘Wachstum durch verzicht – trailer aus dem baukasten’, 6. Aachener

Komplexitäts-Tagung, Aachen, 22.03.2006–23.03.2006, chapter 14.


Nasr, N. (2004) ‘Remanufacturing from technology to applications’, Proceedings Global Conference on Sustainable Product Development and Life Cycle Engineering, Berlin, Germany, 29.09.2004–01.10.2004, pp.25–28.

Seliger, G. (2000) Ökologie als wirtschaftliche Chance, Zeitschtrift für wirtschaftlichen Fabrikbetrieb, Sonderbeilage Sfb 281 Demontagefabriken, 7/2000, Munich, Germany, p.1.

Seliger, G. (2004) ‘Global sustainability – a future scenario’, Proceedings Global Conference on Sustainable Product Development and Life Cycle Engineering, Berlin, Germany, 29.09.2004–01.10.2004, pp.29–35.

Seliger, G. (2007) ‘Roadmap’, in Seliger, G. (Ed.): Sustainability in Manufacturing,Springer-Verlag, Berlin, pp.419–423.

Seliger, G. and Zettl, M. (2007) ‘Modularity for ease of remanufacturing’, in Seliger, G. (Ed.): Sustainability in Manufacturing, Springer-Verlag, Berlin.

Seliger, G., Müller, K. and Perlewitz, H. (1997) ‘More use with fewer resources’, Proceeding of the 4th CIRP International Seminar on Life Cycle Engineering, Berlin, Germany, pp.3–16.

Seliger, G., Müller, K. and Perlewitz, H. (1999) ‘A general approach to disassembly planning and control’, Production Planning and Control, Vol. 10, No. 8/99, pp.718–726.

Seliger, G., Grudzien, W., Middendorf, A. and Reichl, H. (2000) ‘A micro system tool for improved maintenance, quality assurance and recycling’, Proceedings of the CAPE 2000,Edinburgh, Scotland, pp.391–399.

Seliger, G., Kroß, U. and Buchholz, A. (2003) ‘Efficient maintenance approach by on-board monitoring of innovative freight wagon bogie’, Proceedings of the 2003 IEEE/ASME International Conference on Advanced Intelligent Mechatronics (AIM 2003), IEEE Institute of Electrical and Electronics Engineers, Kobe, Japan, pp.407–411.

Seliger, G., Consiglio, S. and Zettl, M. (2004) ‘Selling use instead of selling products – technological and educational enablers for business in ecological product life cycles’, Product Life Cycle – Quality Management Issues, Belgrad, Serbien, 20.06.2004–22.06.2004.

Seliger, G., Consiglio, C., Odry, D. and Zettl, M. (2005) Development of Intelligent Modular Tools for Disassembly in CIRP Design Conference, 22–24 May, Shanghai, China.

Seliger, G., Kernbaum, S. and Zettl, M. (2006) ‘Approaches for sustainable manufacturing’, The 7th International Conference on Frontiers of Design and Manufacturing, Guangzhou, China, 19–22 June, pp.379–384.

Wackernagel, M. (2006) ‘Ecological footprint accounting’, in Mario, K. (Ed.): The Future of Sustainability, Springer, pp.193–209.

Yang, M., Djurdjanovic, D., Mayor, R., Ni, J. and Lee, J. (2004) ‘Maintenance scheduling in production systems based on predicted machine degradation’, submitted to IEEE Transactions on Automation Systems Engineering, Paper No. V2004-067.

Zettl, M., Seliger, G. and Bilgen, E. (2006) ‘Product life cycle oriented methodology supporting the development of modular product structures’, Proceedings of IV Global Conference on Sustainable Product Development and Life Cycle Engineering, Sao Carlos, 03.10.2006–06.10.2006, S. 0 (CD).

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