Novelty and contribution to knowledge

The novelty and contribution to knowledge of the research can be highlighted below

 A detailed review of five popular life cycle impact assessment software package, CES EduPack 2010 Eco audit tool, Solidworks 2010 Sustainability tool, Sustainable Minds, SimaPro 7.2, and Gabi 4 education, has been presented. Based on the comparison results which show advantages and disadvantages of these software in six evaluation criteria, guidelines are proposed for selection of the LCIA software tools for conducting sustainable product design. Furthermore, the analysis, and the comparison results can be used as a reference for researchers in LCIA or LCA area in future. The guideline can help user select suitable software to achieve their goals.

A number of novelties has been proposed and developed within the developed approach for sustainable design. These novelties are listed below:

 The three-tier method for modelling of product life cycle provides a progressive way to modelling the product life cycle and conducts the life cycle impact assessment. In the approach, a product is broken into three tiers: part, subassembly, and assembly. In the modelling of each tier, ecological impacts of different ecological impact elements in life cycle are considered. In the part tier, manufacture, material, process, supply, human labour, energy consumption, etc. are considered. In the subassembly tier, packaging, overhead, etc. are added into consideration. In the assembly tier, the ecological impact elements considered include transportation, packaging, product service life, design for disassembly, product re-use, recycling, and disposal.

 Ecological impact of human labour has taken into account in the LCIA as an input of product life cycle. In the existing literature, human labour has not been considered as an input for LCIA. Existing research often ignores the effect of human activities in the calculation of ecological impact of mechanical products. The research proposed consideration of human labour during the LCIA to restate the importance of human activities in society and natural environment. The modelling of human labour’s ecological impact considers four aspects including food and drink, human metabolism, and transport between home and workplace. The first one is considered as input. The latter two are considered as output to the environment. The model of human labour’s ecological impact is stored in the database of SimaPro. It can be used by other research directly or after minor modification. Also, yes_or_not factor of human labour has been created in SimaPro database. This factor can be modified to include or exclude the ecological impact of human labour in the LCIA. It also can be used to change the distribution of human labour in the product life cycle.

 Optimisation design with the objective of minimise ecological impact and manufacture cost using genetic algorithm. The optimisation design has considered ecological impact and manufacture cost at the same time. Also, it considered environment and economy simultaneously. Manufacturers always consider the economy. And consumers often consider environment. In that case, the optimisation design method can satisfy the requirement from two sides at the same time. The functions, variables, and constraints built in MATLAB can be used by future researcher. Or they can modify them to adapt their requirements.

 Procedure of sustainable product design underpinned by LCIA and design optimisation has been presented. Firstly, a new design produced based on the product specification and it will be modelled and conducted a LCIA in SimaPro to check the ecological impact. If the

results do not satisfied the requirement, the design goes into the optimisation and re-design stage. The optimisation uses genetic algorithm optimisation tool in MATLAB. And then, a LCIA of the optimised design will be conduct. The results of LCIA will be compared with the original design using the unique function of SimaPro to check the optimisation is successful or not. If user satisfied with the results, the design is finished.

 Ontology modelling of gearbox life cycle is present. The ontology has been successfully constructed and can be used to store data in the whole product life cycle. These data in the ontology can be retrieved by user in the life cycle. Also, they can shares data with other users through the ontology. The model of gearbox can be applied into industry such as gearbox manufacture. Or it can be used into other ontology research or collaboration manufacture by other researcher.

 EI-COST is a proposal representation layout, which is a spider net chart, applied to present and evaluate the product specification or illustrate product properties including ecological and manufacture cost. Therefore, the ecological impact has been introduced into product specification stage. Using the EI-COST, the designer will consider ecological impact as a criterion during design evaluation stage. It is also a decision-making tool for sustainable product design.

 Parametric modelling of gearbox life cycle has been modelled in SimaPro. These parameters can be modified by future users to adapt their requirement of application. Other gearbox or mechanical product can be easily modelled based on the parametric model. Manufacture also can use the model to check their product straightforward.

 Spread sheet for communication of software is created. The spread sheet includes the data form gearbox life cycle, LCIA data from SimaPro and ecoinvent database relating to the gearbox life cycle, and optimisation design. All the data needed in the approach is stored in the

spread sheet. It increases the compatibility of the approach. SimaPro, MATLAB, and other software can exchange data with it. It is the key of the whole integrated system of the developed approach. In another word, user can only use the spread sheet to do the LCIA of gearbox because it has all the data LCIA needs. If other potential user modifies the data of gearbox, they can also model their own gearbox in it and complete the LCIA directly.

 Farm food optimisation has been presented. And the ontology of farm food has the same potential usage as the one of gearbox. It is also an attempt to apply the developed approach into other area.

With these novelties, an approach for sustainable design has been developed.