The study is concerned with the conceptual structure and content of the framework for characterising user-product interaction, proposed under the title – ‘Product Semantics’. The sources for the critique of design, from which the framework is derived, are identified and analysed, and the substantive theoretical and methodological content given initial consideration in terms of the deployment of the central concept of ‘meaning’, and the principal theoretical approaches adopted in the analysis of meaning and semantic concepts generally. The commitment to a cognitive and experiential approach to user-interaction is established and the concepts central to the framework, and requiring more detailed analysis, are identified. The core of the study consists in an analysis of the sequence of concepts and contexts that are chiefly used in the theoretical articulation of the framework, including - function, affordance, categorisation, artefacts, meaning and expression - of which the concept of affordance is central to the structure. On the basis of the initial consideration of the structure and content of the scheme, and in the light of the analysis of concepts, the explanatory structure of the framework is established. It is argued that the core commitment to an experiential and cognitive account, and the form of the explanatory structure, are jointly incompatible with the conceptual content of the framework, particularly in respect of the pivotal role of the concept of affordance. Proposals are advanced for an alternative interpretation which addresses the central issues of consistency and coherence, and which suggests an alternative approach to the conceptual characterisation of the framework and the form of the explanatory hierarchy. The implications of the framework, and the proposed alternative interpretation, are considered in respect of their application in shaping approaches to the development of design theory and methodology, and the experiential aspect of semantics and cognition.

Manufacturing globalization and sustainable development compel production enterprises to continuously seek improvements in their products performance, customization, environmental friendliness, cost, and delivery time. The challenges of this competition cannot be completely addressed through improving production processes because some issues can only be solved through more innovative design. This thesis investigates a new design paradigm called Design for Adaptability or Adaptable Design (AD) to address some of these challenges. The purpose of AD is to extend the utility of designs and products. An adaptable design allows manufacturers to quickly develop new and upgraded models or customized products through adapting existing designs with proven quality and costs. An adaptable product can be utilized under varying service requirements thus prevents premature product replacement. Design adaptability and product adaptability provide economical and environmental benefits of AD. <p> To make a product adaptable, its adaptability must be built-in during the design stage. Methods of design for predetermined adaptations are categorized as Specific AD; these methods design products for versatility, upgrading, variety, and customization. Several of these methods such as modular/platform design and design for upgrading have been studied for mechanical design. In the absence of predetermined adaptations, AD aims to increase the general adaptability of products. General AD involves fundamental research in design theory and methodology in order to develop practical design methods and guidelines. This thesis introduces several original concepts and proposes the subordination of a system to a rational functional structure as an approach for increasing general adaptability. Such a system would consist of a hierarchical assembly of autonomous functional modules, emulating the adaptable architecture of a rational functional structure. Methods and guidelines are proposed for making the design of mechanical systems closer to this ideal architecture. <p> Accordingly, the thesis proposes a methodology for AD in which specific AD is performed first to take advantage of available forecast information, and then general AD is performed in order to increase adaptability to unforeseen changes. Also, a measure has been defined for the assessment of adaptability. The application of this methodology has been demonstrated through several conceptual design examples.

Manufacturing globalization and sustainable development compel production enterprises to continuously seek improvements in their products performance, customization, environmental friendliness, cost, and delivery time. The challenges of this competition cannot be completely addressed through improving production processes because some issues can only be solved through more innovative design. This thesis investigates a new design paradigm called Design for Adaptability or Adaptable Design (AD) to address some of these challenges. The purpose of AD is to extend the utility of designs and products. An adaptable design allows manufacturers to quickly develop new and upgraded models or customized products through adapting existing designs with proven quality and costs. An adaptable product can be utilized under varying service requirements thus prevents premature product replacement. Design adaptability and product adaptability provide economical and environmental benefits of AD. <p> To make a product adaptable, its adaptability must be built-in during the design stage. Methods of design for predetermined adaptations are categorized as Specific AD; these methods design products for versatility, upgrading, variety, and customization. Several of these methods such as modular/platform design and design for upgrading have been studied for mechanical design. In the absence of predetermined adaptations, AD aims to increase the general adaptability of products. General AD involves fundamental research in design theory and methodology in order to develop practical design methods and guidelines. This thesis introduces several original concepts and proposes the subordination of a system to a rational functional structure as an approach for increasing general adaptability. Such a system would consist of a hierarchical assembly of autonomous functional modules, emulating the adaptable architecture of a rational functional structure. Methods and guidelines are proposed for making the design of mechanical systems closer to this ideal architecture. <p> Accordingly, the thesis proposes a methodology for AD in which specific AD is performed first to take advantage of available forecast information, and then general AD is performed in order to increase adaptability to unforeseen changes. Also, a measure has been defined for the assessment of adaptability. The application of this methodology has been demonstrated through several conceptual design examples.

Every product has economic, environmental, and social impacts whether or not those impacts are explicitly considered. These impacts affect society and are an important part of engineering design. "Triple Bottom Line Sustainability" focuses on economic, environmental, and social sustainability and has become an important goal for those designing products. Economic considerations are an established part of the engineering design process. Environmental considerations are increasingly being considered in design including the development of design standards and widely used methodologies. Social impact considerations, however, lack the standardization and wide inclusion of economic and environmental considerations. This results in reduced and unbalanced consideration of social impacts compared to economic and environmental impacts. Improved consideration of social impacts in engineered products would benefit society in many areas of life. While many tools and methodologies for assessing social impact exist and are used in the social science and development fields, these tools are not broadly used in the engineering community. Some reasons these methods are not more standardly practiced include designers not being aware of the methods, methods not being widely applicable or adaptable, methods being too complicated or time intensive to use, or methods not being useful in product development processes. The purpose of this research is to classify and organize design tools for social impact and create methods that fill holes in the social impact design tool space. The classification and organization is done through the classification of 374 papers in the EGD literature along several dimensions including method purpose, industry sector, social impacts considered, sustainable development goals, paper setting, and data inputs required. This will increase awareness of available methods and help designers find relevant research to aid them. Additionally, this research describes two methods developed by the author to fill specific gaps identified in the literature.