Water Jet Cutting Machine - Case Study Example

Introduction Coming up with innovative products is seen as a critical intervention point towards transforming society towards sustainability. Evidence showing that the current methods applied in decision making in product innovation are insufficient include resources being over used and the socio-ecological impacts witnessed in production, distribution, utilization and disposal. In numerous cases it turns out that the products; socio-ecological impact will have already been committed in the design phase. For companies to be able to improve their competitiveness and be able to identify long term investment that are viable as well as new opportunities in the fast evolving sustainability driven market, there is need for them to have socio-ecological sustainability aspects included. There have been proposition of several tools or methods that would ensure there is integration of environmental aspects in development of products. Some examples of the are 'sustainable product development', 'eco-design', 'design for(the) environment', 'pollution prevention', 'design for recycling', and 'cleaner production (van Weenen,1997; de Caluwe, 1997; Tischner, et al ,2000) . But the achievement realized in “greening” of products has been low, with the likely reason for this situation being limited time and economic resources that could be used in ensuring that there is effective application of eco-design methods ( Hanssen, O.-J. (1996). Lack of other incentives other than the environmental benefits may also be seen to be the other reason. Some of the eco-design tools that are currently applied have been seen as having what could be referred to as vague connection to social and business aspects of sustainable development (Byggeth, S.H. and Horschorner, E., 2006). This has motivated the development of some tools that aim at bridging this gap. This bridging toots include Systems Modeling within Sustainability Constraints, Templates (Ny, H.,2006) for Sustainable Product Development (Ny, H., et al., 2005).Strategic Life-Cycle Management ( Hanssen, O.J.1996), and Method for Sustainable Product Development (Horschorner, E., 2006). Technical assessment of functionality of the product is another aspect of product development whose importance cannot be overemphasized. This may be achieved either through computer simulation or by physical testing. Simulation has the major advantage of making it possible for test to be done on a number of design proposals within a limited time frame and money as opposed to the case with physical testing (Hanssen, O.J.1996). By having some of the technical aspects of a product being simulated product design optimization is achieved. A good example is the case of using a virtual machine in the investigation of how having some desirable changes in machine tool properties may be accomplished by having changes in design variables [14, 15]. The short coming however, is that such optimization are seen as having narrow focus towards technical and to some extent business aspects. In order to address the issue of sub-optimization it is better to have integration of prioritization decisions in economic perspective. Taking into consideration the use phase of the product is also important. So far it can be said that there is no optimization procedure in common use where there is combination of life-cycle parameters resulting from a sustainable assessment with those that are as a result of technical assessment. Having such a combined optimization procedure may be a good way of ensuring that there is provision of valuable support in achieving sustainable product development. This papers looks at sustainable development with focus on the water jet cutting machine innovation. In the paper ideas of iterative optimization procedure are featured where there is inclusion of technical assessment and sustainable assessment. Such approach is believed to result to a win win-win for company, the customer and the society at large. 2.4 Sustainability Assessments of the Water Jet Case 2.4.1 Strategic Life-Cycle Management In overarching sustainability assessments SLCM and ABCD are the tools of choice. ABCD is used in the identification of main potential sustainability related problems with a principle solution being given for the company, product or activity. There could be a chance of upgrading the ABCD assessment to a SLCM in a more systemically with integration of a life-cycle overview where there would be inclusion of supply chain, manufacturing, use and reuse and disposal or recycling. In both ABCD and SLMC suggestion is given on how there can be prioritization between potential solution applicable to the problem. In the water jet cutting machine SLCM was applied in making the overarching strategic action plant and the activities associated with its life-cycle. SLCM when applied to the water jet cutting machine indicated that the electricity used could be of concern. This is because the electricity that was being used was being generated in a manner that is not sustainable. Recommending that electricity be bought from renewable sources would map out and reduce the of energy and material use. 2.4.2 Causal Loop Diagrams and Reference Behavior Patterns The use of Causal Loop Diagram (CLD) as a tool aims at clarifying the causal link between the variables featuring in a problem. In CLD variable connection is effect by use of positive and negative arrows denoting either an increase or a decrease in the target variable when there is an increase in source variable. The intention of Reference Behaviour Pattern (RBP) is mapping out potential behavior over time with regards to key variables in the CLD. In CLD tool system boundaries are set by specific questions that the tool will attempt answering. In relation to the present case iterations were forced on the investigation of the question: what type of relationship exist between the life-cycle of water jet cutting machine, the sustainability impact of the machine and the customer demand for the water jet cutting services. Assessment of the CLD brought about a wider perspective with regards the factors that contributes sustainability impacts of water jet cutting (Figure 1). The CLD indicated that by having improvement in technical performance through reduction of moving weight, cutting accuracy being increased and increased speeds there could be reduction in energy and material use in the life-cycle of the machine. There could also be reduction in sustainability impacts and costs related to these. The CLD assessment gave an open chance more assessment to be done later with regards to socio-ecological consequences of the design changes that would have been suggested by technical assessment. CLD also resulted to sophisticated technical reasoning. A good example is where decreasing of the moving weight would result to reduction in other aspects of machine performance such the accuracy level in cutting and speed. By the cutting accuracy being reduced there would be increase in the need to have post-operations which could in turn result to increase in energy demand in the entire manufacturing process and also resulting in addition of other negative side effects as seen from a larger sustainability perspective. Also failure to have high speed maintained would lead to increased consumption of water which has a negative impact on sustainability. Figure 1 2.5 Technical Assessments of the Water Jet cutting machine 2.5.1 Estimations and Hand Calculations The first step in the assessment of technical aspects of the conceptual design would the derivation of a mathematical model that has an analytical solution based on hand calculation. In the present case the estimated stresses in structure is as a result of bending loads resulting from the operation of the machine. Preliminary results indicated that having a lighter or stiff design would principally be used with no risk of encountering of structural failure. 2.5.2 Finite Element Calculations In a more detailed model the hand calculations are taken to a further calculation that would encompass product components with the included components and their interactions and boundary conditions are represented more realistically. In general case it present a difficult attempting to describe a product with such simplicity that an analytical solution can be found. These then present s a case where there is often the use of numerical methods such as finite elements are frequently used. For the sake of increasing the knowledge of systems being studied there maybe need of conducting parameter studies. In the water cutting machine there was use of finite element model of the machine in a parameter study in sorting out , for the specific design criteria the influential design parameters. 2.5.3 Virtual Machine Modeling and Simulation Machine tools may be described as being mechatronic systems meaning that they are muiltidisciplinary products that have both mechanical and electronic components and incorporate controls that are computerized. Successful design of such systems would call one to have overall understanding of the behavior of the entire system. There therefore calls having a simulation tool that is far much more advanced where there is incorporation of all relevant aspects of multiple disciplinary design problems. A previously developed virtual machine was applied in the water jet cutting machine. The virtual machine has a real control, system, a hardware-in-the-loop simulator of the machine and also a reality model used for visualization peruses. The virtual machine is utilized in a parallel multidisciplinary design approach, and is able to analyze the mechanics and control simultaneously so that there is utilization of the interaction effects. The virtual machine modeling and simulation has been found being superior when compared to traditional sequential design approach (Wall, J.,2007). The virtual machine in this case had several sub-models namely the finite element model used in the simulation of flexibility of the mechanical parts that are moving; a motor model as well as a multi-body model of the transmission. There was parameterization and automation of the simulation model meaning hat the optimization algorithm had the ability to have influence on the model through variation of some aspects of it, such as the geometric quantities or the material properties. With the input from sustainability assessment being given there was identification and subsequent parameterization of all the major moving components of machine in the virtual machine. 2.5.4 Virtual Machine Optimization Study In a design optimization there is need for clarifying both the objective and the way of varying design parameters so as to achieve the object. This means that we need to have some algorithm capable of identifying the design parameter combination that matches with the objective. The optimization study of the water cutting machine had a primary objective of reducing the weight of the major moving parts, whose origin was the TSPD sustainable assessment. The other performance objectives were the high cutting accuracy and speed were also to be put into consideration and both had sustainability implications that were seen in CLD and the discussion related to it. For this reason and in ensuring traditional competitiveness of the new alternative machine designs that were assesses in optimization study, cutting accuracy and speed was not allowed to deceases with respect to current levels. This means that design problem encompassed a mixture of variables that were continuous and discrete. There was use of generic algorithm owing to its ability of solving problems of this nature. Through inclusion of both mechanical and control system parameters simultaneously in optimization study, there could be avoiding of there being a tradeoff between lightness and accuracy and/or speed. The optimization study indicated that there was room for improvement. It was found that the weight of main components could be reduced by more than 30% with the cutting accuracy being able to be improved by 60 percent maintained cutting speed. 2.6 Societal Sustainability Consequences The CLD can be used is the estimation of societal consequences of design changes resulting from technical assessment. The effect of having a reduced moving weight was put into focus in this case, and in particular how this could result in lowering of energy use and indirectly how emission of CO2 could be lowered and as a result of which there would be lower contribution to global climate change. Generally, through energy savings more often it would make both the society’s and organization’s transformation towards energy systems to be easier for a number of reasons. By energy being saved, for example, there may be reduction in costs and would thereby make it possible for investments to be made renewable energy alternatives. Since the whole previous energy amount needs are not to replaced by new energy sources (because of energy savings), there is likely to be faster transformation towards use of renewable energy and other sources that are more sustainable. With the assumption being that use of electricity is proportional to the moving weight, then there is a possibility that electricity consumption will be reduced by up to 30 percent. 3. Result Water jet cutting machine has revealed the potential of applying integrated sustainability and technical assessment. The working procedure is seen to be interactive and iterative thus revealing the design variables that have the highest socio-ecological impacts. The integrated system assessment procedure can be expressed in general terms. Overarching sustainability assessment is required to scrutinize the water jet cutting and other competing techniques so as to identify the major sustainability problems in present day flow practices. There is also generation of ideas of long term principle solution and visions and on the basis of this first idea the likely desirable changes in machine properties can be obtained. The next step involves performing of introductory technical investigation with the aim of assessing if these particularly desirable changes in machine properties can be realized in principal. There is then feeding back of the obtainable changes in a new and more refined sustainable assessment so as to find out the changes imply at society level. In turn there will be a chance of this resulting to other desirable changes, may require a new and more refined technical assessment. 4. Conclusions In this there is suggestion of working procedure for a combined sustainability and technical assessment so as to facilitate design optimization that is informed by societal perspective. Water jet cutting machine is used as the case study in addressing sustainability issues. There is use of both overarching and sustainability related and technical methods/tools in arriving at design changes that support sustainable development of society. References van Weenen, H.( 1997) Design for sustainable development: guides and manuals. (European Foundation for the Improvement of Living and Working Conditions, Dublin, Ireland, 1997). de Caluwe, N. (1997). Eco-tools manual: A Comprehensive Review of Design for Environment Tools. (Design for the Environment Research Group, Manchester Metropolitan University Manchester, UK, 1997). Tischner, U et al (2000). How to do Ecodesign?A guide for environmentally and economically sound design. (German Federal Environmental Agency., Berlin, Germany). Hanssen, O.-J. (1996). Sustainable industrial product systems: Integration of life cycle assessments in product development and optimization of product systems. (Norwegian University of Science and Technology/Østfold Research Foundation, Trondheim/Fredrikstad,). van Hemel, C. and Cramer, J. Barriers and stimuli for ecodesign in SMEs. Journal of Cleaner Production, 2002, 10, 439-453. Byggeth, S.H. and Horschorner, E. (2006). Handling trade-offs in ecodesign tools for sustainable product development and procurement. Journal of Cleaner Production, 14(15-16), 1420-1430. Byggeth, S.H., et al (2007) A method for sustainable product development based on a modular system of guiding questions. Journal of Cleaner Production, (15), 1-11. Ny, H., et al. (2005). Introducing templates for sustainable product development through case study of televisions at Matsushita Electric Group. (Department of Mechanical Engineering, Blekinge Institute of Technology, SE-371 79, Karlskrona,Sweden., submitted). Ny, H.(2006) Strategic Life-Cycle Modeling for Sustainable Product Development. Department of Mechanical Engineering, p. 131 (Blekinge Institute of Technology, Karlskrona, Sweden, ) Wall, J.(2007). Simulation-driven design of complex mechanical and mechatronic systems. Mechancial Engineering, p. 184 (Blekinge Institute of Technology, Karlskrona, 2007). Read More

Having such a combined optimization procedure may be a good way of ensuring that there is provision of valuable support in achieving sustainable product development. This papers looks at sustainable development with focus on the water jet cutting machine innovation. In the paper ideas of iterative optimization procedure are featured where there is inclusion of technical assessment and sustainable assessment. Such approach is believed to result to a win win-win for company, the customer and the society at large. 2.4 Sustainability Assessments of the Water Jet Case 2.4.1 Strategic Life-Cycle Management In overarching sustainability assessments SLCM and ABCD are the tools of choice.

ABCD is used in the identification of main potential sustainability related problems with a principle solution being given for the company, product or activity. There could be a chance of upgrading the ABCD assessment to a SLCM in a more systemically with integration of a life-cycle overview where there would be inclusion of supply chain, manufacturing, use and reuse and disposal or recycling. In both ABCD and SLMC suggestion is given on how there can be prioritization between potential solution applicable to the problem.

In the water jet cutting machine SLCM was applied in making the overarching strategic action plant and the activities associated with its life-cycle. SLCM when applied to the water jet cutting machine indicated that the electricity used could be of concern. This is because the electricity that was being used was being generated in a manner that is not sustainable. Recommending that electricity be bought from renewable sources would map out and reduce the of energy and material use. 2.4.2 Causal Loop Diagrams and Reference Behavior Patterns The use of Causal Loop Diagram (CLD) as a tool aims at clarifying the causal link between the variables featuring in a problem.

In CLD variable connection is effect by use of positive and negative arrows denoting either an increase or a decrease in the target variable when there is an increase in source variable. The intention of Reference Behaviour Pattern (RBP) is mapping out potential behavior over time with regards to key variables in the CLD. In CLD tool system boundaries are set by specific questions that the tool will attempt answering. In relation to the present case iterations were forced on the investigation of the question: what type of relationship exist between the life-cycle of water jet cutting machine, the sustainability impact of the machine and the customer demand for the water jet cutting services.

Assessment of the CLD brought about a wider perspective with regards the factors that contributes sustainability impacts of water jet cutting (Figure 1). The CLD indicated that by having improvement in technical performance through reduction of moving weight, cutting accuracy being increased and increased speeds there could be reduction in energy and material use in the life-cycle of the machine. There could also be reduction in sustainability impacts and costs related to these. The CLD assessment gave an open chance more assessment to be done later with regards to socio-ecological consequences of the design changes that would have been suggested by technical assessment.

CLD also resulted to sophisticated technical reasoning. A good example is where decreasing of the moving weight would result to reduction in other aspects of machine performance such the accuracy level in cutting and speed. By the cutting accuracy being reduced there would be increase in the need to have post-operations which could in turn result to increase in energy demand in the entire manufacturing process and also resulting in addition of other negative side effects as seen from a larger sustainability perspective.

Also failure to have high speed maintained would lead to increased consumption of water which has a negative impact on sustainability. Figure 1 2.5 Technical Assessments of the Water Jet cutting machine 2.5.

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