Phasing  process
AbstractNowadays, the cities are rapidly growing bigger and the world’s population is becoming more and more lopsided towards the urban share. The ever-rising scale of urbanization makes the built environment challenges much more troublesome and brings up disquieting uncertainties about the future of human life on earth.  Although the urbanization seems to be inevitable due to the role of the cities as the innovation centers and economic engines, its numerous negative aspects are widely threatening the environment and the social structures.  Thus, the only way for man to secure his continuity on earth is appearing to be a fundamental reconsideration of his developing practices, especially, in the built environment.  There were many attempts in the last three decades to reform the development model in the built environment, but most of them were doomed to fail, basically for innate flaws in approaching the built environment as a complex system. The current study refers to Integrated Modification Methodology (IMM) as its scientific ground and regards the built environment as a Complex Adaptive System of which the basic morphological elements are built-ups, voids, links and the types of uses. Espousing the basic principle of the System Theory that a system's performance is rigorously ruled by the patterns of interconnection between its parts, this paper offers a comprehensive framework for redefining and modeling the integration mechanism of the urban subsystems and formulating the relationship between the structural arrangements and the system's performing manners. The ultimate objective would be to deliver a theoretical scheme of a cybernetic model which assists the decision makers in predicting the systemic reactions of the built environment to the modification scenarios.  Key WordsBuilt Environment, Sustainability, Ecology, Systems, Complex Adaptive Systems, Sustainable Indicators, Urban Morphology, Key Categories, Morphological Attributes, Structural Tools, Evaluation Tools, Operational Facet, Modelling MethodologyIntroductionIn today’s world, built environment plays the most key role in socio-economic relations and the environment is being affected most dominantly by urban life.  Cities are growing fast, and faster are growing the numbers of urban inhabitants. At present, more than half of the world’s population lives in cities and it is estimated that this ratio will increase to 70 percent by 2050.  It means that if they are not managed now, the urban-related issues we are facing today will be taken to much more intensity tomorrow and even more severe environmental risks and socio-economic conflicts are yet to arise. Currently, about 80 percent of the global primary energy is being consumed in urban areas, cities are being guilty of emitting more than 60 percent of the total world’s greenhouse gases, and the list of social issues in urban arrangements are endless. On the other hand, cities are the economic engine of the world, and by being on average responsible for more than 75 percent of a country’s Gross Domestic Product (GDP) their further expansion is an inevitable perspective.  In this situation, and as sustainability becomes the main development framework for all parts of economic communities, adopting innovative approaches towards development in the built environment is becoming urgent.  The built environment is composed of various morphological, typological, and technological subsystems from which the performing manner of the entire system is originated. Claiming sustainability in urban establishments demands a comprehensive understanding of cities as complex systems and clear identification of the role player subsystems within them. The majority of current trends and design methods adopt simplified analytical approaches and practically deal with the subsystems as independent entities; hence neglect the importance of phenomena resulting from their interconnections in different scales. With the aim of developing a better understanding of the built environment’s systemic structure, the intention of the proposed research is to offer a holistic methodology for studying the behavior of the built environment. This goal will be pursued through an inquiry into the morphological components of the urban systems and the complex relationships between them. The result will be a theoretical platform for assessing the actual behavior of the architectural compositions and predicting their potential performance associated with different intervention scenarios. Literature Review Over the course of its conceptual evolution, sustainability has been portrayed as an edifice supported by three pillars of economic growth, environmental protection, and social progress\citep{Kastenhofer_2005}. It is commonly accepted that the goals of the sustainable development are manifested in the convergence of the above-mentioned realms of knowledge United Nations General Assembly \cite{1} . Today, almost two decades since Brundtland Report called for balancing economic development with social and ecological integration \citep{Buys2014} the interconnectedness of the development challenges within and in-between the three pillars of sustainability are becoming more and more apparent, and the importance of interdisciplinary approach toward sustainability research has taken on new urgency \citep{Cumming2017} \citep{Kates2001}. In fact, sustainability has been characterized as a multidisciplinary field concerned more with problem-solving \citep{Walter2007} and overcoming challenges than the disciplines it employs \citep{Clark2016}. Many studies currently carried out in the field of sustainability can be ironically observed as significant institutional and structural obstacles to what interdisciplinary studies supposedly pursue \citep{Kostoff2009}. Likewise, in the realm of architecture, many sustainable oriented trends are trapped in mono-disciplinary systems. Most of such studies with the absolute concentration on minimizing the negative environmental impacts of buildings can be categorized solely as the environmental methodologies. As a matter of fact, even though environmental science has the widest audience of sustainability research, found to be making less connection across pillars of knowledge. However, the built environment by encompassing all the aspects of human life provides an important context for sustainability to be practiced in a full integrative manner.  The built environment is a living and dynamic system. Planners and architects could play a fundamental role in the pursuit of sustainability through balancing social improvement and economic development alongside environmental protection in their designs. Consequently, rather than merely concerning the components, they may aim to transform the entire system into a more diverse and productive network. Until now, by applying the principals of ecological design, sustainable architecture set its ultimate goals on energy efficiency and minimizing the environmental impact. The efforts made on this subject such as hiring technologically advanced materials in construction, encouraging the use of renewable forms of energy, and developing efficient waste management methods are essential and valuable but not necessarily sufficient. The focus on individual buildings’ architectural issues does not involve dynamic attributes related to the composition of urban features. In recent years, it has been proven that concentrating on green engineering alone is not sufficient to achieve sustainability because even subsystems with efficient materials and energy use can overwhelm the capacity of the entire system or lead to socially unacceptable outcomes \citep{Mihelcic2003}. Therefore, sustainability must be quested in multi-scalar manners and in integration with all the built environment’s subsystems. Targeting on single buildings as independent entities are similar to installing high-performance hardware on a computer’s motherboard without considering the systemic composition and the whole system’s capacity. Recent movements which seek sustainability in larger scales too, do not seem to address the problems of the built environment in a holistic way. They are often trapped in analytical approaches suggesting linear strategies and unconsciously striving for one-dimensional solutions. After decades of practice, the New Urbanism trend is proven to be reproducing suburban sprawls in the form of empty aspirational utopia [18]. Moreover, the importance of adopting locally based approaches is being neglected by the commandment-like universal principals imposed by New Urbanism. Similarly, planning theories like Smart Growth, despite sketching out ethically acceptable principals, have failed to achieve their claimed goals. In many projects developed in accordance with such strategies, no evidence has been found to indicate any tangible effects on development patterns. It is argued that such strategies “tend to intensify the very problems they are purported to solve” Wendell Cox 2002). There are also movements like Landscape Urbanism claiming to work on ecological improvement through focusing on the urban landscape rather than the buildings. Having been practiced in numerous expensive projects across the world, there are serious uncertainties among the ecological thinkers regarding the actual functionality of this theory. Ecology is the branch of science concerned with the interrelationship of the organism and their environment. It is the science of interaction between components, aggregation of elements and systems. Whilst landscape urbanism is characterized by the scientific reductionist approach. No scientific evidence could be found supporting that setting up the design based on urban landscape could lead to an overall sustainable result. There are many subsystems involved in the urban metabolism among which landscape alone, merely as an urban component, cannot provide the integration and adaptivity needed to maintain the optimum complexity for a sustainable performance. In short, Landscape Urbanism lacks in the holistic approach which is a fundamental element for controlling the comprehensive performance of the systems. Therefore, it is not surprising to witness this movement fails to achieve the performance goals set by itself. The growth of the non-motorized traffic for instance (as an objective of Landscape Urbanism movement), would be the result of an optimum arrangement of high-density buildings, diversity of urban function, and an acceptable level of accessibility all supported by local features rather than the attractive and well-placed urban parks.   In general, a regular set of incapability could be diagnosed in all the mentioned methodologies aiming for sustainability through predefined design principals: In most of them, urban elements have been considered as the main transformation tool (high or low-density buildings, landscape, mobility system etc.) whilst the performance of a system is rooted in the way that the elements are structured together. Thus, for intervening a piece of build environment to change its performance, there is a requirement to work in another dimension of architectural arrangements where the quality of the relationship between elements appears. By solely concentrating on large-scale development they miss the opportunity to take an integrative approach towards different scales of the built environment. Consequently, they ignore or misaddress the agents functioning in-between the urban and architectural scales.They declare design standards while lacking in systematic assessment criteria. Therefore, it is difficult to classify the achievement of such methodologies and relate them to the sustainability indicators. Practically, through inevitable compromise between their principals, technical and ethical conflicts might arise, whilst there are no standards available for retrofitting.They are pursuing sustainability mostly in future development and suggest less for the existing situation. However, considering the amount of energy being consumed in developed urban areas and the range of socio-economic conflicts which established cities are currently facing, it is unavoidable to take a modification-oriented approach. They tend to simplify the complex structure of the built environment, hence striving for straightforward answers for solving complex problems. However, as a socio-ecological system, the built environment is a dynamic context of complexity and adaptation. Approaching such a system “requires serious study of the complex, multivariable, nonlinear, cross-scale, and changing” organizations.  Considering this background and with the aim of bridging the above-mentioned gaps, this research proposal tends to offer a holistic methodology for studying the complex behavior of the spatial urban systems and the network of relationships within their subsystems. Research ObjectivesThe chief objective of this research will be to present a framework for modeling the built environment’s dynamic behavior. This model is expected to provide the opportunity of evaluating the performance of the built environment in actual stages and predicting its possible reactions under different intervention scenarios. This research will be theoretically based on Integrated Modification Methodology (IMM) introduced in the ABC Department of Politectinco di Milano at 2011. This methodology addresses the complexity of the spatial settlements and their multi-level integrative order across different scales. Two main factors will make this research distinguishable from the similar studies: 1. the holistic approach through which the built environment will be regarded as a multi-layered synthesis of various morphological (or morphology maker) systems, and 2. the intention of visualizing mathematical-based predictions of the city’s natural reactions to possible intervention scenarios. Considering the intricacy of the urban arrangements, the core of this research will be to map the system of built environment’s adaptive behavior. This system mapping will draw an intellectual framework for developing an assessment tool to examine the spatial arrangements with.  Moreover, it will structure the whole intervention methodology suggested by this proposal. Naturally, the assessment tool will be developed as a simulation model used for:Identifying the morphological manifestation of the built environment’s behavioral subsystemsInvestigating the linkage between the subsystems and classifying the resulted morphological parameters and conceptual attributesInvestigating the hierarchy of scales defined by the interconnection of the mentioned attributes Investigating the mathematical/logical orders governing the morphological/conceptual attributes; detecting the network formed by these orders, its structure and its effecting pattern on urbanization, socio-economic and environmental features This model is expected to deliver a systemic understanding of the complex network of relations hidden behind the urban physical structure. In other words, it reveals the properties of the very system that the whole methodology is intended to study and modify. Thus, although its development is a part of the methodology’s procedure, the simulation model will also play a fundamental role in defining the objectives in all the other stages of this research. Furthermore, it will enable the methodology to evaluate itself and, parallel to intervention process, evolve through a non-linear path while it is being applied. Within this framework, it would be possible to develop a locally-based approach and adopt more objective modification strategies. Ultimately, it will become an apparatus for predicting the built environment’s response to different intervention scenarios as well as estimating the global reaction to local actions within the system’s boundary. Therefore, the proposed methodology is expected to become a decision support tool for construction and management activities flexible enough to conceptually expand with respect to the multi-finality of the built environment and its various environmental and socio-economic subsystems.MethodologyTheoretical Background With a philosophical shift from the concept of sustainability, this research sets its goal for introducing a theoretical platform for understanding the behavior of the built environment from an ecological viewpoint. During the recent two decades, sustainability has been practically defined with many variations and sustainable development has been misinterpreted many times as the sum total of individual attempts for improvement in different areas of action. Occasionally, with an inclination towards economy, mainly consumer-driven growth model, sustainability failed to target the synergic patterns inside systems and seemed to be more of a compensation science. In this regard, sustainable development became a confrontation between human and earth within which man tries to secure his economic future only by trying to scientifically predict the linear consequences of his actions and minimize the potential risks. Considering the tremendous level of complexity in the socio-economic and the environmental systems, such an attempt is doomed to failure. A proper approach would be acknowledging the nature of the systems and move along with accordance to their principles.  Ecology, on the other hand, is the science of integration between the systems. It seems to be a more sensible development context since it concerns with recognizing the relationships and observing the structure of the system. Therefore, an ecological development means a practice of growth that meets the needs of man in total integration with the ecological system of which man himself is a part.  Clearly, the judgment whether a piece of built environment could be considered ecologically sustainable or not is a matter of performance. Thus, any methodology claiming for ecological sustainability must offer tangible mechanisms for evaluating the system’s performance.  Depended on the lifecycle of the system, defined boundary and the purpose of the assessment, the evaluation processes might vary widely. However, just like any other system, most of the methods for evaluating the built environment are structured around comparable indicators. Relying on the existing evaluation methods, the chief focus of this doctoral research would be on understanding the systemic structure of the built environment from which the performance is being originated.  For this, it is necessary to investigate the patterns of relationship between systemic configuration and the resulting performance. According to the System Theory, there are four properties common in all types of systems: 1. They are composed of elements; 2. There is a relationship between elements; 3. There is a certain function associated with any system (however, many systems including built environment are multi-final systems meaning that numerous functions are associated with them); and 4. There is a boundary defined for any system \citep{Ramage_2009}.  It is crucial to notice that the functioning manner of any system is fundamentally directed from the relationship between the parts. Therefore, the way that the elements relate to each other plays a much more decisive role than the elements themselves. All the cities on the planet composed of common elements such as buildings, parks, roads and streets, transportation means, parking areas etc. yet no two cities are to be found to share the exact same performance. For the functioning manner roots from the rather hidden dimension of relationships, any attempt for controlling the performance of the build environment systems by solely working on the level of the elements will be ultimately facing methodological conflicts in theory and unforeseen consequences in practice.This study refers to Integrated Modification Methodology (IMM) as its theoretical skeleton and works to refine the structural links between the Investigation and Formulation phases through a numerical modeling methodology.  IMM recognizes the built environment as a Complex Adaptive System (CAS) \citep{Manesh_2011} comprised of numerous subsets and many variables interacting in various levels, various scales, and a diverse set of subcategories. Rendering the CAS’s nature, a mere local action accrued in an individual subset will produce a chain reaction within the network of its parts and trigger a process which consequently leads to the global change of the entire system. In other words, system agents adapt themselves in response to the complex network of reactions arisen from individual changes.  IMM is based on a nonlinear phasing process involving the following structure \citep{Manesh_2013}:Phase I. Investigation: Analysis and Synthesis Phase II. Assessment and FormulationPhase III. Intervention and Modification Phase IV. Optimization