This thesis examines how novel invariants called the "stability index" as proposed by Podvigina and Ashwin can be used to characterize the local geometry of riddled basins of attraction for both skew and non-skew product systems. In particular, it would be interesting to understand how the stability index behaves on the basin boundary between multiple basins of attraction. Then we can ask this question: How can we identify when a basin is riddled? To answer this, we present three models with the presence of riddled basins. In the first model, we present a skew product system of a simple example of a piecewise linear map. We prove that the riddled basin occurs within a certain range of parameter and calculate the stability index analytically for this map. Our results for the stability index at a point show that for Lebesgue almost all points in the map, the index is positive and for some points the index may be negative. We verify these results with our numerical computation for this index. We also make a corollary claiming that the formula for the stability index at a point can be expressed in terms of the stability index for an attractor and Lyapunov exponents for this map. This suggests that this index could be useful as a diagnostic tool to study bifurcation of the riddled basins of attraction. In the second model, we refer to a skew product map studied by Keller. Previously, Keller computed the stability index for an attractor in his map whereas in this thesis, we use an alternative way to compute the index; that is on the basins of attraction for Keller's map, found by inverting his map. Using the same map, we also verify maximum and minimum measures as obtained in his paper by studying Birkhoff averages on periodic points of Markov map in his system. We also conjecture result by Keller and Otani on the dimension of zero sets of invariant graph (i.e. basin boundary) that appears in Keller's map to a complete range of a parameter in the map. The last model is a non-skew product map which is also has a riddled basin. For this map, we compute the stability index for an attractor on the baseline of the map. The result indicates that the index is positive for Lebesgue almost all points whenever the riddled basin occurs.

This study investigates product development of complex products in a modular environment at the paver manufacturer Dynapac. It is determined how the complexity of a modular product constrains product development.Product development in a modular enviornment is a popular research topic in previous literature. However there is limited literature regarding in what ways the complexity of a modular product constrains product development in form of new product variants demanded by the market. A more comprehensive research within this field is interesting for manufacturing companies producing complex products in a modular environment since it could ease and optimize their product development processes. An efficient product development process is crucial to stay competitive and to be able to serve the market rapidly with qualitative and desired products, which increases the importance of this study.With the aim to address the limitations of the existing literature on product development based from modular complex product systems a case study was conducted. The constraints of developing a new paver model demanded by the market caused by the complexity of the paver design were identified.The findings of the research have both theoretical and managerial implications. The theoretical contribution consists mainly of the identification of a new type of overall constraints in modular complex product systems which I call ‖architectural functional constraints‖. These constraints cause an unexpected chain reaction of affected modules in the product system when a change to one module is made, even if the change ostensibly only should affect the module in question. The results show that the effects of this type of constraints is a constraining factor on product development of new product variants in a modular environment. The effects of the architectural functional constraints constrain product development since they trigger time consuming activities in order to avoid a dysfunctional product, or a product that has a high level of commonality with other product offerings. Further the effects oppose a rapid and cost-efficient product development which is regarded to be two of the main benefits with modularity.The managerial implications include a decision process for new product development projects that can be used when architectural functional constraints are found in a product in order to ensure an economic sustainable development of new product variants. Hence managers can use the decision process as a tool to both make and communicate current and future decisions in a structured way.The study is a starting point for further studies investigating how the complexity of modular products might constrain product development efforts. It is expected that the results of the study can be used by other manufacturing companies operating in a similar context, producing complex product systems in a modular environment.

Increased use of data is influencing the existing practices in the engineering domain,including that of systems engineering. Complex products and systems (CoPS), along with its predominant methodology of development, Model-based systems engineering(MBSE), is no exception to this. This thesis explores the possible integration of the emerging data driven methods and the established model-based methods in the context of CoPS development. It also explores what the implications of such an integration could be for the organizations building such systems, the system integrators. To analyse the current state of the art in CoPS development and model based methods as well as the emerging trends in data driven methods, this research employs an integrative literature review method. The literature search concluded in 71 selected articles to be reviewed. These articles where divided over three main categories, CoPS, Model-based systems engineering (MBSE) and data driven methods.The results of the analysis suggest that data driven methods and the model-based methods complement rather than compete throughout the innovation life cycle of CoPS. The findings indicate that an integration of the methods is beneficial to the architectural, systemic, and component level innovation in CoPS. MBSE and data driven methods could however have different levels of influence in these three types of innovation. The findings indicate that MBSE could have more influence in architectural innovations, while data driven methods could be more influential in systemic and component innovation. The continuous innovation in the use phase of system is also seen to be improved by this integration. The system integrators benefit from the improved project to project learning resulting from the integration which enhances their economy of repetition. An integrated method could also increase the speed of which decisions can be made while still maintaining reliability in the system. The results indicate that the number of iterations could increase due to the increased feedback of data and the learnings gained from it, which could pose some challenge to the existing project management methods. Further research is needed to find out what are the full benefits of an integrated method and identify other potential conflicts.

A linear model of consumption − produce-use-dispose − has constantly increased the pressure on the environment in recent decades. There has been a great belief that technology will solve the problem, but in many cases it is only partly contributing to the solution. For a full solution, the root causes of problems need to be identified. The drivers-pressures-state-impact-response (DPSIR) framework allows the drivers of a specific problem to be identified by structuring the causal relations between humans and the environment. A state/ impact-based approach can help identify pressures and drivers, and make what can be considered an end-of-pipe response. Rather than that mainstream approach, this thesis adopts a pressure-based driver-oriented approach, which could be considered a proactive approach to environmental resource management. In physical resource management, material flow analysis (MFA) is one of the tools used for communication and decision support for policy response on resource productivity and pollution abatement. Here, element flow analysis (EFA), a disaggre- gation of MFA for better mass balance, was applied in pollution control and resource management. The pressure-based driver-oriented approach was used to model element flows and thus identify the drivers of problems in order to improve pollution control and resource management in complex systems. In one case study, a source-storage-transport model was developed and applied in five lakes in the Stockholm region to identify the drivers of copper pollution by monitoring the state of the environment through element flow modeling linking diffuse sources and fate in the lakes. In a second case study, a system dynamics modeling approach was applied in dynamic element flow modeling of the global mobile phone product system to investigate the drivers for closing the material flow loop through a sensitivity analysis. In a third case study, causal loop diagram modeling was used for proactive resource management to identify root causes of a problem in a complex system (product systems of physical consumer goods) by qualitatively analyzing unintended environmental consequences of an improvement action. In the case study on lakes in the Stockholm region, the source-transport-storage model proved capable of predicting copper sources through monitoring the sediment copper content in the heavily copper-polluted lakes. The results also indicated how the model could help guide policy makers in controlling copper pollution. The system dynamics study proposed an eco-cycle model of the global mobile phone product system by tuning the drivers, which could lessen the pressures on resources by decreasing the resource demands for production and increasing resource recovery at product end-of- life. The causal loop diagram study showed that a broader systems approach is required to understand and identify the drivers for proactive resource management in a complex system, where improvement actions can lead to unintended consequences. / <p>QC 20150420</p>

Many of the sustainability challenges our society currently face have arisen as unanticipated side effects of our own modern developments. This thesis investigates if unintended consequences and perspectives are fully addressed by traditional methods for providing decision-making support within the sustainability domain. For that purpose, Systems Thinking is utilised in three cases: in the first, Systems Thinking is used to analyse sustainability issues relating to the current product design paradigm. In the second case, Systems Thinking is applied to two product systems – household washing machines and conventional passenger vehicles. The third case discusses different stakeholder perspectives in environmental decision-making and proposes a way to combine the ESA tools LCA, LCC and CBA in order to consider the different stakeholder perspectives. Results of the first case point out that the practices within the current design paradigm are focused on innovations and improvements in material and energy efficiency. These practices have led to the following unintended consequences: consumption rebound effects, increased waste, pollution, negative externalities, economic inequalities and other environmental and social negative impacts. These unintended consequences are represented in a Causal Loop Diagram (CLD). The diagram graphically illustrates how these unintended consequences influence one another and interact by means of cause-effect linkages and reinforcing feedback loops. A novel conceptual framework named Sustainability-Driven Systems-Oriented Design is proposed to work within broader system boundaries in order to address possible negative side effects that micro-level gains could have on macro-level losses. In the case of the two product systems, a CLD for household washing machines and conventional passenger vehicles is developed. The CLDs represent how selected variables interact by means of cause-effect associations to affect environmental impacts of the products. The CLD technique appears to be a useful way to connect quantitative assessment (from Life Cycle Assessment) with qualitative analysis (from Systems Thinking). In the third case it is argued that stakeholders tend to adopt different system boundaries and make assumptions according to their perspective when they use ESA tools in environmental decision-making. A way to combine ESA tools is suggested to facilitate the observation of the environmental decision from different viewpoints. It concludes, to some extent, that traditional methods for providing decision-making support can handle certain parameters that may result in unintended consequences. Systems Thinking may assist in the process of performing qualitative analyses of what is important to consider in order to strengthen the robustness of, and improve on the recommended actions from, quantitative detailed analyses. / <p>QC 201305330</p>