Poor cost performance of construction projects has been a major concern for both contractors and clients. The effective management of risk is thus critical to the success of any construction project and the importance of risk management has grown as projects have become more complex and competition has increased. Contractors have traditionally used financial mark-ups to cover the risk associated with construction projects but as competition increases and margins have become tighter they can no longer rely on this strategy and must improve their ability to manage risk. Furthermore, the construction industry has witnessed significant changes particularly in procurement methods with clients allocating greater risks to contractors. Evidence shows that there is a gap between existing risk management techniques and tools, mainly built on normative statistical decision theory, and their practical application by construction contractors. The main reason behind the lack of use is that risk decision making within construction organisations is heavily based upon experience, intuition and judgement and not on mathematical models. This thesis presents a model for managing global risk factors affecting construction cost performance of construction projects. The model has been developed using behavioural decision approach, fuzzy logic technology, and Artificial Intelligence technology. The methodology adopted to conduct the research involved a thorough literature survey on risk management, informal and formal discussions with construction practitioners to assess the extent of the problem, a questionnaire survey to evaluate the importance of global risk factors and, finally, repertory grid interviews aimed at eliciting relevant knowledge. There are several approaches to categorising risks permeating construction projects. This research groups risks into three main categories, namely organisation-specific, global and Acts of God. It focuses on global risk factors because they are ill-defined, less understood by contractors and difficult to model, assess and manage although they have huge impact on cost performance. Generally, contractors, especially in developing countries, have insufficient experience and knowledge to manage them effectively. The research identified the following groups of global risk factors as having significant impact on cost performance: estimator related, project related, fraudulent practices related, competition related, construction related, economy related and political related factors. The model was tested for validity through a panel of validators (experts) and crosssectional cases studies, and the general conclusion was that it could provide valuable assistance in the management of global risk factors since it is effective, efficient, flexible and user-friendly. The findings stress the need to depart from traditional approaches and to explore new directions in order to equip contractors with effective risk management tools.

The following thesis deals with methods to increase the reliability of the results in life cycle assessment. The paper is divided into two parts. The first part points out the typologies and sources of uncertainty in LCA and summarises the existing methods dealing with it. The methods are critically discussed and pros and cons are contrasted. Within the second part a case study is carried out. This study calculates the carbon footprint of a cosmetic product of Li-iL GmbH. Thereby the whole life cycle of the powder bath Blaue Traube is analysed. To increase the reliability of the result a procedure, derived from the first part, is applied. Recommendations to enhance the product´s sustainability are then given to the decision-makers of the company. Finally the applied procedure for dealing with uncertainty in LCAs is evaluated. The aims of the thesis are to make a contribution to the understanding of uncertainty in life cycle assessment and to deal with it in a more consistent manner. As well, the carbon footprint of the powder bath shall be based on appropriate assumptions and shall consider occurring uncertainties. Basing on discussed problems, a method is introduced to avoid the problematic merging of variability uncertainty and data uncertainty to generate probability distributions. The introduced uncertainty importance analysis allows a consistent differentiation of these types of uncertainty. Furthermore an assessment of the used data of LCA studies is possible. The method is applied at a PCF study of the bath powder Blaue Traube of Li-iL GmbH. Thereby the analysis is carried out over the whole life cycle (cradle-to-grave) as well as cradle-to-gate. The study gives a practical example to the company determining the carbon footprint of products. In addition, it meets the requirements of ISO guidelines of publishing the study and comparing it with other products. Within the PCF study the introduced method allows a differentiation of variability uncertainty and knowledge uncertainty. The included uncertainty importance analysis supports the assessment of each aggregated unit process within the analysed product system. Finally this analysis can provide a basis to collect additional, more reliable or uncertain data for critical processes.

The following thesis deals with methods to increase the reliability of the results in life cycle assessment. The paper is divided into two parts. The first part points out the typologies and sources of uncertainty in LCA and summarises the existing methods dealing with it. The methods are critically discussed and pros and cons are contrasted. Within the second part a case study is carried out. This study calculates the carbon footprint of a cosmetic product of Li-iL GmbH. Thereby the whole life cycle of the powder bath Blaue Traube is analysed. To increase the reliability of the result a procedure, derived from the first part, is applied. Recommendations to enhance the product´s sustainability are then given to the decision-makers of the company. Finally the applied procedure for dealing with uncertainty in LCAs is evaluated. The aims of the thesis are to make a contribution to the understanding of uncertainty in life cycle assessment and to deal with it in a more consistent manner. As well, the carbon footprint of the powder bath shall be based on appropriate assumptions and shall consider occurring uncertainties. Basing on discussed problems, a method is introduced to avoid the problematic merging of variability uncertainty and data uncertainty to generate probability distributions. The introduced uncertainty importance analysis allows a consistent differentiation of these types of uncertainty. Furthermore an assessment of the used data of LCA studies is possible. The method is applied at a PCF study of the bath powder Blaue Traube of Li-iL GmbH. Thereby the analysis is carried out over the whole life cycle (cradle-to-grave) as well as cradle-to-gate. The study gives a practical example to the company determining the carbon footprint of products. In addition, it meets the requirements of ISO guidelines of publishing the study and comparing it with other products. Within the PCF study the introduced method allows a differentiation of variability uncertainty and knowledge uncertainty. The included uncertainty importance analysis supports the assessment of each aggregated unit process within the analysed product system. Finally this analysis can provide a basis to collect additional, more reliable or uncertain data for critical processes.

The purpose of this study is to generate an understanding of first-time buyers of high involvement products, by examine how they search for information and evaluate alternatives. Three research questions were formulated to achieve the purpose of the study. Two of them concern first-time buyers’ behavior and the third one aims to answer if any possible explanations to their behavior could be identified. The study is based on theories within the research field of consumer behavior regarding purchase behavior, the consumer decision process, decision making style, involvement and knowledge along with uncertainty. In order to answer the purpose and the associated research questions, data was collected with a qualitative approach through semi structured interviews. The empirical data was analyzed by a thematic analysis, derived from a model based on the theoretical framework. The results of the study indicate that first-time buyers do not consider their internal information search adequate, and therefore search for further information externally. Their external information search tends to involve several sources. The sources credibility seems to be based on previous experiences from other situations. How they evaluate alternatives also seems to be influenced by previous use of cut-offs and decision rules, to simplify their decision making. Further the results argue that the stages search for information and evaluation of alternatives is rather integrated and iterative than detached. However, it appears that the decision-making style of first-time buyers of high involvement products differ in their degree of involvement, levels of knowledge and experienced uncertainty. Both the complex and the dissonance reducing buying behavior is occurring in first-time buyers of high involvement products. Additionally, the results indicate that tendencies of both a complex and dissonance reducing buying behavior could be identified in one individual.This study is written in Swedish. / Syftet med den här studien är att skapa en förståelse för förstagångsköpare av högengagemangsprodukter genom att undersöka hur de söker information och utvärderar alternativ. Tre forskningsfrågor formulerades utifrån studiens syfte, varav två rör förstagångsköpares beteende och den tredje ämnar ge svar på eventuella förklaringar till deras agerande. Studien utgår från teorier inom forskningsfältet för konsumentbeteende som berör köpbeteende, köpbeslutsprocessen, beslutsfattarstil, engagemang samt kunskap och osäkerhet. Med ett kvalitativt angreppssätt samlades data in genom semistrukturerade intervjuer för att ge svar på syftet med tillhörande forskningsfrågor. En modell togs fram baserat på den teoretiska referensramen som sedan låg till grund för en tematisk analys av empirin. Studiens resultat visar att förstagångsköpares interna informationssökning inte är tillräcklig vid högengagemangsköp, vilket resulterar i att ytterligare information söks externt. I den externa sökningen tenderar de att söka information från flera källor. Källornas trovärdighet verkar bedömas utifrån deras tidigare erfarenheter från andra sammanhang. Även utvärderingen influeras av tidigare tillämpning av brytpunkter och beslutsregler som underlättar beslutsfattandet. Det framgår också att stadierna informationssökning och utvärdering av alternativ snarare sker integrerat, i en iterativ process, än var för sig. Studiens resultat bekräftar att beslutsfattarstil, engagemang samt kunskaps- och osäkerhetsnivå influerar informationssöknings- och utvärderingsprocessen hos förstagångsköpare av högengagemangsprodukter. Däremot framgår det att förstagångsköpare av högengagemangsprodukter har olika beslutsfattarstil, grad av engagemang samt besitter olika nivåer av kunskap och upplever varierad grad av osäkerhet. Både ett komplext och dissonansreducerande köpbeteende förekommer hos förstagångsköpare av högengagemangsprodukter. Dessutom visar resultatet att det kan identifieras tendenser som tyder på både ett komplext och dissonansreducerande köpbeteende hos en och samma individ. Studien är skriven på svenska.