Mega construction projects are complex undertakings. The complexity is increased during a construction boom in a city such as Dubai where more than 80% of material and labour resources are imported. The complexities inherent in mega construction projects include uncertainty and interdependencies, which affect project management performance at the operational level where most of the problems occur. Understanding these processes, how they interrelate and how to overcome the complexities is crucial for increasing the chances of project management success. This research contributed to construction project management theory and practice by using a highly inductive exploratory qualitative approach for capturing formal and informal processes in mega construction projects in Dubai. A dynamic model depicting the complementary formal and informal processes is developed showing formal and informal processes and how they interrelate to reduce complexity. Guidelines on how and when to use specific processes are provided as a framework for the model. This framework may be used to help develop communication processes in future complex projects to increase chances of project management success. The research was conducted by exploring two case study projects fitting the characteristics of mega construction projects. Both case study projects were of values above 1.5 Billion US Dollars and were similar in scope with elements including amusement parks, retail areas, hotels, extensive infrastructure and large landscape areas. Both case study projects were of an experimental character, considered an engineering achievement, complex, and thereby, difficult to control. The research data were collected through semi-structured interviews with 83 project staff from both case study projects. Rich picture diagrams of the organization and processes were made from data collected during the interviews and case study project documents. The analysis was performed in three phases where the results from each phase were built upon cumulatively. The first phase examined what the most crucial critical success factors (CSFs) were in the case study projects. These were revealed to be communication, top management support and effective change management. In the second phase each CSF was analyzed where it was found it that the majority of important communication modes were informal and were was most effective in reducing complexity. Furthermore, it was found that the characteristics of the client were crucial in both case study projects. The third phase involved development of the dynamic hybrid model from the rich picture diagrams created showing the interplay between formal and informal processes. It was found that informal processes are ad-hoc and chaotic in nature and controlled by individuals in the project. Development of guidelines for the positive use of informal processes was required. From the analysis it was found that the characteristics of client staff and individuals in the case study projects provided the main guidelines for effective use of the hybrid model. The research provides insights into the formal and informal processes and the reduction and management of complexity inherent in mega construction projects. Current research in managing complexity is from the perspective of the formal process where the informal processes are neglected, despite research and practice indicating their importance in construction projects. The research presents a systemic dynamic model of the processes for mega construction projects revealing that formal and informal processes are required and are complementary. Guidelines for the successful use of the model provide a framework for its application in practice. This shows how it can be used to inform understanding of processes in the context of the research. The model and guidelines were validated via discussions with practitioners experienced in construction of mega projects. Future work should expand the findings to applications of the model in practice for management of complex projects. The model may be used by practitioners to act as a guide in how to manage construction processes to consciously overcome the inherent complexities to achieve project management objectives. This tool may also be used to inform clients of the inherent complexities and the level of informality required to overcome them. IT/IS practitioners may use the model and framework to understand the complexities in construction, and thereby, develop systems that are practically applied in construction projects. Researchers in the field may build upon the model and findings to increase knowledge regarding construction processes, particularly informal processes.

In managed forests, the enormous complexity of an ecologic system meets a vast range of economic and other impact factors. Thus, to determine, analyze and understand economically optimal stand management is a task which has kept forest economists occupied for the past 200 years. The approach which has been followed since the days of Martin FAUSTMANN is the analysis of models which describe rather specific management scenarios using a set of clearly defined model assumptions. Unfortunately, the applicability of the findings to more general scenarios is limited. On the other side, the possibility of analyzing general management environments with single models is also limited by increasing complexity. Thus, a holistic understanding of optimal forest management is still missing. This statement also holds for the extensive field of optimal even-aged timber production, which essentially consists of only three main components, i.e., planting, thinning and final harvest. Therefore, this dissertation aims to make a contribution to further increase the general understanding of even-aged forest management. To achieve this goal three steps were taken. First, a qualitative analysis of a combined management plan including decisions on all three basic components is presented based on HALBRITTER and DEEGEN (2015). It provides a discussion of the direct and indirect dependencies between the decision variables of a rotation in a rather classical management environment. Second, three studies are presented which dissolve some of the classical model assumptions and extend the existing knowledge on even-aged forestry to relevant but more complex mangement questions. HALBRITTER (2015) includes natural regeneration and a shelter period in an even-aged system and explores the borders between the even- and uneven-aged management. Thereby, the influence of natural regeneration and the impact of several age classes were studied. HALBRITTER (2020) drops the assumption of stand homogeneity and investigates stand management under heterogeneous tree growth in which, for example, different social classes of trees are maintained. Lastly, HALBRITTER et al. (2020) extend the classical deterministic management environment in the direction of density-dependent hazard risk. This adds an additional aspect to the thinning and the rotation decision because, in this scenario, the probability of stand destruction can be controlled by thinning. As a third step, the studies above were embedded in a patchwork representing a conglomeration of models which are connected and validated by overlapping scopes. Using this approach, a wide range of different management scenarios can be covered by rather simple models. Thus, the complexity of the analysis decreases compared to single models with a more generally applicable framework and the problem of model complexity is mitigated. In addition, the inclusion of reference models with a particular focus on the management components stand establishment, thinning or rotation allows for a clear identification of the relationship between optimal stand management and the characteristics of a scenario. Applied to the qualitative analysis of the four studies above, the approach yields insights which contribute to a better understanding of even-aged forest management.:1. Introduction 2. The FAUSTMANN Framework 2.1 Model Definition 2.2 The FAUSTMANN Model 2.3 Assumptions 2.4 Basic Applications 2.4.1 The Rotation Model 2.4.2 The Thinning Model 2.4.3 The Planting Model 2.4.4 The Uneven-aged Model 3. Problem 4. Methodology 5. The Combined Model 5.1 Model 5.2 Optimal Management 5.3 Impact of Timber Price and Interest Rate 5.4 Discussion in Comparison to the Basic FAUSTMANN Applications 6. Extensions 6.1 Uneven-Aged Extension: The Double-Cohort Model 6.1.1 Even-Aged and Uneven-Aged Stands 6.1.2 Model 6.1.3 Optimal Management 6.1.4 Impact of Timber Price and Interest Rate 6.1.5 Discussion in Comparison to the Basic FAUSTMANN Applications 6.2 Heterogeneous Extension: The Heterogeneous Stand Model 6.2.1 Homogeneous and Heterogenous Stands 6.2.2 Model 6.2.3 Optimal Management 6.2.4 Impact of Timber Price and Interest Rate 6.2.5 Discussion in Comparison to the Basic FAUSTMANN Applications 6.3 Stochastic Extension: The Natural Risk Model 6.3.1 Deterministic and Stochastic Scenarios 6.3.2 Model 6.3.3 Optimal Management 6.3.4 Impact of Timber Price and Interest Rate 6.3.5 Discussion in Comparison to the Basic FAUSTMANN Applications 7. Conclusions 7.1 Optimal Management Strategy 7.1.1 Optimal Planting 7.1.2 Optimal Thinning 7.1.3 Optimal Rotation 7.2 The Patchwork Approach 7.2.1 Applicability of the Patchwork Approach 7.2.2 Limitations of the Patchwork Approach 7.2.3 Comparison to the Holistic Approach 8. Summary

Complexity is the paradigm of the 21st century and has been discussed in several fields of research. During the last years, increasing complexity in manufacturing companies has been one of the biggest issues in science and practice. Companies in high-technology marketplaces are confronted with technology innovations, dynamic environmental conditions, changing customer requirements, globalization of markets and competitions, as well as market uncertainty, inducing an increasing amount of complexity. Manufacturing companies cannot escape these trends. In today’s highly competitive environment, it is fundamental for company’s success to develop and launch new products quickly and with customer’s individual settings to the market. The companies cope with these trends by developing new product variants, which lead to an increased complexity in the company and in product development. Complexity is influenced by internal and external sources of complexity, so-called complexity drivers. Complexity drivers have an influence on companies and the total value chain. Managing a system’s complexity requires an optimum fit between internal and external complexity. Identifying, analyzing and understanding complexity drivers is the first step for complexity management’s development and implementation. For managing and optimizing company’s complexity, a vast number of different single approaches is applied for different purposes. Complexity management is a strategic issue for companies to be competitive. The main important strategies for single approaches’ application are complexity reduction, mastering and avoidance. Complexity management requires approaches for complexity’s understanding, simplification, transformation and evaluation. A successful complexity management approach enables a balance between external market’s complexity and internal company’s complexity. The purpose of this dissertation is to close existing gaps in scientific literature by providing a complexity management in variant-rich product development. Therefor, a systematic literature review was performed regarding the issues ‘complexity drivers in manufacturing companies and along the value chain and their effects on company’s complexity’, ‘application of specific single approaches and their targeted strategy’, as well as ‘approaches for complexity management and especially for resource planning’. An empirical research was conducted to document the current state in the German manufacturing industry regarding the issues ‘complexity drivers in product development and their effects on company’s complexity’ and ‘application of specific single approaches for complexity management’. The empirical data was collected through questionnaires between 2015 and 2016. The empirical findings are compared with literature to identify commonalities and differences. Based on literature’s results, a new general approach for managing complexity in variant-rich product development was developed to bring the relevant steps for complexity handling in a sequence. In this approach, complexity in product development is systematically analyzed and evaluated to create conditions for target-oriented managing and controlling of complexity. Furthermore, the general complexity management approach is modified and structurally optimized to establish a target-oriented approach for resource planning in variant-rich product development. The new approaches are applied in the automotive industry to verify the results and approach’s applicability.

[pt] A presente tese teve como objetivo principal construir, validar e discutir a pertinência de índices que relacionassem aspectos da gestão escolar (liderança do diretor, autoeficácia pedagógica do diretor e complexidade da gestão) com o desempenho e a equidade dos resultados dos alunos dos anos finais do ensino fundamental. A pesquisa foi um estudo quantitativo de natureza exploratória, tendo como amostra principal as escolas da rede municipal do Rio de Janeiro que ofertam nono ano e foram avaliadas no SAEB 2019. Complementarmente foram realizadas análises para as escolas que ofereciam o quinto ano da mesma rede e para as escolas públicas do Brasil de quinto e nono anos que participaram do SAEB 2019. Em termos metodológicos, foram construídos três índices por meio da análise fatorial: o Índice de Liderança do Diretor (ILD), o Índice de Autoeficácia Pedagógica do Diretor (IAEPD), e um Índice de Complexidade da Gestão (ICG) para a rede municipal do Rio de Janeiro, alternativo ao índice criado pelo INEP. Foram então realizadas regressões lineares multivariadas usando a média da proficiência em matemática dos alunos e seu desvio padrão em cada escola como variáveis dependentes e o Índice de Nível Socioeconômico (Inse) do INEP como variável de controle. Os principais resultados indicaram que a liderança do diretor e a crença em autoeficácia pedagógica do diretor apresentaram correlação positiva com a proficiência e com as desigualdades no desempenho dos alunos. Quanto a complexidade da gestão a correlação foi negativa: quanto mais complexa a escola, pior o resultado dos alunos. Não foi possível encontrar resultados estatisticamente confiáveis para a relação entre a complexidade da gestão e a equidade do desempenho dos alunos. Os modelos para o Rio de Janeiro só apresentaram significância estatística em alguns coeficientes para o quinto ano. Todos os índices e respectivos coeficientes tiveram significância estatística nos modelos nacionais. / [en] The main objective of this thesis was to construct, validate, and discuss the relevance of indices that relate aspects of school management (principal s leadership, principal s pedagogical self-efficacy, and management complexity) to the outcome and equity of students results in the final years of elementary school. The research was a quantitative study of exploratory nature, having as main samplethe schools of the municipal network of Rio de Janeiro that offer 9th grade and were evaluated in SAEB 2019. In a complementary way, analyses were carried out for schools that offered 5th grade in the same system and for Brazil s 5th and 9th grade public schools that participated in SAEB 2019. In methodological terms, three indices were constructed using factor analysis: the Principal Leadership Index (PLI), the Principal Pedagogical Self-Efficacy Index (PPSEI), and a Management Complexity Index (MCI) for the municipal system of Rio de Janeiro, an alternativeto the index created by INEP. Multivariate linear regressions were then performed using the average math proficiency of students and its standard deviation in each school as dependent variables and INEP s Socioeconomic Level Index (SELI) as control variable. The main results indicated that the principal s leadership and the principal s belief in pedagogical self-efficacy were positively correlated with student proficiency and achievement inequalities. Management complexity, on the other hand, showed a negative correlation: the more complex the school, the worse the student achievement. It was not possible to find statistically reliable results for the relationship between management complexity and equity in student achievement. The models for Rio de Janeiro only showed statistical significance in some coefficients for the 5th grade. All indices and respective coefficients were statistically significant in the national models.