For equipment or plant replacement, when to replace an existing plant, fleet or a part of it, is one of the main concerns in decision-making. The thesis considers this decision-making problem using capital replacement models with a fixed planning horizon, and we took at the behaviour of optimal policy in this context. Application of the models is considered and we compare replacement models with a fixed planning horizon with replacement models with a variable planning horizon models comprising of two cycles. Capital replacement modelling in general and previous work done in the field are reviewed. The main work of this thesis is the study of the behaviour of optimal replacement policy for a single equipment/fleet over a fixed planning horizon, with a numerical investigation of the behaviour for non-like-with-like replacement. This is extended to describe the behaviour of optimal policy for replacement of a mixed fleet. A case study is presented that applies the fixed planning horizon model to a bus fleet; this fleet is operated by a Malaysian inter-city bus company. Finally we consider the challenger problem. Throughout, we recommend the use of a fixed planning horizon model rather than a two cycle variable-horizon model. The rent criterion is also our favoured criterion for decision-making; the rent criterion exists and is well behaved for all the models described. A dynamic programming approach is implemented for the like-with-like replacement problem over a fixed planning horizon for comparison with the economic life modelling approach of this thesis. We discuss the use of the different replacement decision models for supporting replacement decision-making in practical contexts.

This thesis contributes to the area of performance measurement in facilities management (FM). The context of the study is FM organisations. Interest in performance measurement increased dramatically during the 1990's in both management and academic literature. Performance measurement systems developed as a means of monitoring and maintaining organisational control, which is the process of ensuring that an organisation pursues strategies that lead to the achievement of overall goals and objectives. A performance measure can also be defmed as a metric used to quantify the efficiency and/or effectiveness of an action. The role of FM in promoting organisational performance, and thereby in providing competitive advantage is widely acknowledged. Although performance measurement concepts are referred to in the FM literature, they have not been applied with the same rigour as with other academic areas, such as production and manufacturing. Institutions will want support services that offer the best possible standards to meet the users' needs. Better coordination between core activities and support services means that institutions can respond faster and more effectively to those demands for services. Herein lies the general theoretical gap, which forms the point of departure for this research. This thesis aims to outline the many different perspectives of performance measurement in FM organisations. A grounded theory approach has been adopted with the aim of building theory as opposed to testing theory. Case studies were conducted at several FM intensive organisations. The identification of performance measurement tools or mechanisms was one of the aims of the case study phase, as well as providing descriptive accounts of the process. These tools and mechanisms were incorporated into a performance measurement questionnaire and were evaluated against the FM organisations in UK. The research uncovered performance measurement constructs in FM which could be categorised under the following four broad perspectives: customer, FM internal processes, FM learning and growth and financial FM. At each level, the FM organisation should strive to make performance measurement visible with the aim of creating new performance measurement constructs. Developed theory was further validated against a panel of experts in the field of FM and in a real life case study. The findings from both the qualitative and quantitative data points to an FM organisational performance measurement process which depends on the existing knowledge base of the FM organisation. The contribution to knowledge in the field may be viewed in terms of a critical examination of the role of performance measurement and the implications these have for the core organisation as the contribution made by FM will ultimately be judged by the organisation's stakeholders over a wide range of performance criteria including both fmancial and non-financial. FM is seen to be able to contribute to performance in many ways: strategy, control of resources, service efficiency, supply chain management and perhaps, most importantly, providing value for money. Furthermore, the constructs and concepts developed in this thesis provide both a point of departure for further research and a practical tool with which to assess performance measurement and management with the FM organisation.

Trapezoidally corrugated sheeting has been previously studied with regard to applications in shear diaphragms, making use of its inherent strength and stiffness properties by suitable connections. The in-plane deflection is an important design factor and the shear distortion component, due to eccentric transfer of fastener force into profile shear, is a major contributor to the total. A design formula is developed for the distortional shear flexibility for _ets fastened in every trough and in intermediate purlins which takes account of the localized distortion at the sheet ends by using an energy method analysis of assumed displacement functions to represent plate bending. For fastening in alternate or multiple of troughs, an additional profile concertina distortion occurs, resulting in a large increase in the shear flexibility. A similar energy method is performed as for the previous case, developing the same basic formula for the distortional deflection. A corresponding study is made for sinusoidally corrugated sheeting. A number of practical design factors have been examined - including the effect of longitudinally overlapping sheets, and purlin restraint on profile distortion. For sheets spanning over rafters into different shear fields, the expressions for shear flexibility have been modified. The strength of diaphragms has been investigated, especially with regard to fastening on two sides only, which includes the torsional and bending stiffness of laterally weak purlins. Diaphragm openings cause an increase in the sheet flexibility and constrain purlins to follow the resulting displaced shape. Consequently locally high purlin bending stresses and sheet-purlin forces may be generated, as revealed by differential equation and finite element studies. Corrugated sheeting has many applications in frameless structures such as folded plates and hyperbolic paraboloids. The flexibility and strength expressions have been used to design a prototype three bay folded plate roof which utilizes specially pressed sheeting to reduce the shear distortion component of roof deflection, The shear buckling strength of corrugated diaphragms is an impottant factor in such construction. For larger roof diaphragms with only periodic intermediate fixings to purlins, buckling may occur over the complete diaphragm depth rather than separately in each bay, and design tables are shown for this condition.

This research discusses and analyses the role of construction in economic development in Sub-Saharan Africa, with a special emphasis on Angola and Mozambique. This study follows research undertaken by previous writers who have investigated the relationship between the construction sector and economic development and found a direct relationship between the share of construction in gross domestic product (GDP) and GDP per capita in an increasing form of per capita income level. Data on construction and economic related sectors spanning generally 22 years are used to model the development pattern of the construction industry in Sub-Saharan African countries for the near future. The statistical sources used in this analysis are drawn from World Bank and United Nations publications. Additionally, field study data, including collection of secondary data, from Angola and Mozambique are used in detail to complement data provided by international sources. The construction sector operating environment including policy changes in the area of general economic policy of these countries are also addressed in this study. Studies on construction in developing countries have tended to approach the construction industry in the context of the process of industrialisation, towards a long-term economic growth. It is argued that the new approach should focus the construction industry in the general framework of the determinants of growth. This thesis puts forward evidence that a long-term decreasing growth in GDP per capita corresponds directly to a relative decrease in construction volume. The converse does not appear to be true. Some implications for public policy for the concerned countries are discussed.

In external city environment areas there is a poor understanding and often no conscious use of colour. The experts that work with colour, in terms of the built environment either as projectmakers, or as managers (decision-makers), are poorly prepared to deal with it. As an answer they minimise the problem of colour in architecture, especially in exteriors, simply by omission; or, they introduce colour mostly without criteria - in some projects colour plays only a cosmetic role - supposedly aesthetical. Most project-makers do not consider colour as an integral part of the global design process. Colour theory and teaching courses have been considered supplemental to the mainstream of architectural education; for most part of the students of architecture or landscaping architecture, colour remains a matter of individual taste. People in general are very conscious of colour and texture in the built environment and they really like variations (as some studies done in Sweden (Koller 1981; Mahnke 1993) have already showed). They are negative and critical of austere, colourless environments in our cities; also colour has psycho-therapeutic effects that can be utilised to meet the physiological needs of people living in crowded environments. Colour is one of the basic components of the environment which influences life quality and it can be approached from different perspectives and different disciplines. This research addresses the issue of colour in the architecture of the built environment analysing the behaviour of the unity which results from the straight relationship between colour and space(as quantity of colour): the Colour/Space Unity. The investigation shows not only the existence of this unity, but also that it is a unity of visual communication. In terms of allocating the findings and interpretations through a review of the relevant theory, the author uses a survey methodology - a full test response questionnaire to a wide range of members of society (to test theory) and semistructured interviews with a panel of experts(as a feasibility test of the questionnaire design and contents). The questionnaire findings are used to test the theoretical position through further comments from the expert panel. The research presents as results, not only the existence and importance of the colour/space unity, as a visual communicational one, such as the levels of articulation of the messages in the built environment or the contrast in the relationship between qualification and quantification in colour/space language; but it demonstrates the major importance of the colour/space unity in the architectural project and in the colour planning management within the built environment.

Turner's (1965,1967,1968) study of Lima's squatter settlements led to the view that uncontrolled settlements of the Third World cities are mainly a manifestation of the desires for housing ownership by people who are well integrated in the city and have experienced some amount of social mobility. In his work, Turner (1968) advanced a theoretical model of intraurban mobility in which rural-urban migration; upward social mobility, intra-urban mobility and the growth of spontaneous settlements are inter-related. Within this model, migrants are classified into three successive groups which corresponds with their level of involvement in gainful employment namely, 'Bridgeheader' i. e. the newly arrived migrants who are in search of employment or involved in low paid jobs, 'Consolidators' i. e. those who have had some urban experience and are"in relatively better paid jobs; and 'Status Seekers' i. e. the upper class of low income group. Three housing priorities: - Location, security of tenure and quality of housing and environment were assigned to those class of migrants. Upward economic and social mobility from a low paid job to a better paid jobs, is argued within this model, to be reflected in a housing priority and expectation about living conditions. Those who move from lower position in the social hierarchy to a higher position also move from inner city slums to the suburbs. In other words, social mobility necessarily entails spatial mobility within the urban. environment. Security of tenure and improvement of the quality of housing are thus functionally related. Consequently, it is recommended that stimulating those spontaneous activities as opposed to their eradication would benefit enormously from the resourcefulness of the squatters. Legalisation of land tenure, provision of infrastructural services and support-for local neighbourhoodorganisation are some of the essential elements for a more healthy urban policy. In this study attempt is made to test Turner's model of intraurban mobility in a regional context of West Africa. The study specifically examines the validity of the model in relation to a secondary city of (Jos) Nigeria, and asks whether Turner's model which is based almost entirely on the migratory characteristics and experience of Latin America has gone far enough in acknowledging the various dimensions of Third -World rural-urban migration in which some migrate permanently while others intend only a temporary migration as well as the varying types of uncontrollecl subareas that have emerged as a result of these differences. In most of West Africa, Including Nigeria, rural-urban migration tends not only to be temporary in character but is also structured by kinship relationships. Within this migratory context, migrants do not strive to consolidate their stay in the city. They prefer cheap rental accommodation, with a view to consolidating their position in the rural home towns. Security of tenure does not therefore rank. high in their order of priorities, their social mobility does not lead to a spatial mobility. Within this migratory context, the distinction between permanent and temporary migrants has more validity and practical application than Turner's bridgeheader - consolidator dichotomy, since bridgeheaders are likely to remain bridgeheaders while in the city. Adopting the proposed distinction between permanent and temporary migrants provides a lot of insight into the ways in which migrant groups perceive the city environment and how their perception of the city in turn affects the development process of their settlement areas. Indeed, varying migratory characteristics leads to varying housing demands and housing ambitions in the city of migration. This also leads to variation in migrants reception areas in the city and thus affords the capacity of uncontrolled subareas to improve via self help housing. Thus, the distinction between permanent and temporary migrants provides a lot of insight into the understanding of why some uncontrolled settlements might improve through self help housing and why others might not. Most Importantly, it provides more insights into the policy dimension of the problem.

During the last few decades most developing countries have experienced a rapid growth in population which has resulted in a rapid urbanisation in the form of an expansion of existing towns, coupled with an increasing dependence upon developed countries for implementation of new housing programmes. The purpose of this study is to point out the problems of public housing, to identify the relationships between the physical elements and conceptual perspectives of housing functions. To resolve the housing problems, the Libyan government introduced a new policy, which recognised housing as a basic human need and provision of housing as the governments' fundamental responsibility. The aim of the study was to assess the effectiveness of the implementation of the public housing policy in Tripoli, the capital city of Libya. To achieve this aim both secondary and primary data were examined, and the required data was obtained through a questionnaire survey of households living in the three projects. Interviews were also conducted amongst government officials concerned with housing policy and implementation. This study is in general, concerned with the effects of the problems of the new social and physical environments on the residents' level of satisfaction with the housing projects. This study is mainly concerned with aspects of housing policy which might contribute to better housing satisfaction and which are responsive to changes in people's desires and preferences. After the evaluation process it is found that the Libyan housing policy has benefited large groups of people, particularly those on low-income. However, it also suggests that the adopted policy has not resolved the housing problems both in terms of quantity and quality. In particular, the dwellings provided have not met the needs of many Libyan families. Furthermore, the study found that there is a lack of housing management. This evident from some households living in the dwellings without permission in addition, the rate of sharing and occupancy shows that there is still a housing shortage. The study also shows that the dwelling and building construction types affect the resident attitudes to dwellings. Also shows that, most of the residents' prefer new dwellings.

Electronic Trading is a business relationship that relies upon the use of computer and telecommunication technology for information exchange. In order to understand the development of electronic trading between construction firms, the CONNET model was developed. This model identifies the factors and variables determining whether firms adopt electronic trading systems, and its configuration. The model is grounded in the relationship perspective and network approach, and assumes that there is mutual commitment and an economic rationale behind the development of electronic trading. The CONNET model explains that electronic trading systems emerge from the complex interplay of three major factors. These are: a) the relationship between the two firms, i.e. what is exchanged (information, product, financial, social) and how (power/dependence, co-operation, closeness, mutual expectations); b) the business and IS/IT strategies, and the organisational and IT infrastructures and processes of each of the firms; and c) the characteristics of the web of relationships - production network, in which the firms are embedded, i.e. interconnections, input-output structure, governance structure and territoriality. In order to validate the model, six case studies were conducted in construction situations and four in automotive and retailing situations. Analysis of the data collected concluded that some variables have a more important role in the adoption decision, e.g. social contacts, business strategies or territoriality. Other variables are influential on the adoption but more important on the configuration of the systems, e.g. TT strategies and organisational and IT infrastructures. Most variables have an influence on both the adoption decision and the configuration of systems, e.g. information and finance exchanges, co-operation, individual interconnections, or governance structure, though the importance of their influence varies. It was concluded that, in general, electronic trading and sophisticated systems emerge where there is a higher concentration of enabling factors. The implications of the validated model lie in its potential use in explaining when and how electronic trading is likely to occur in construction. By exerting influence over variables in the model it can be used by construction organisations to create an environment to encourage electronic trading to take place.

This thesis describes the development of a knowledge based system which encapsulates some of the expertise used by a number of experienced construction planners for planning the construction stage of low rise house building projects in the U.K. The general objective of the research was to investigate the feasibility of using knowledge engineering for developing models of construction planning expertise, which could be employed for tackling some of the existing knowledge bottlenecks in the construction industry. The resulting system can be described as a knowledge based framework designed for supporting the decision making process involved in planning house building at a tactical level. One of the main features of this framework is its ability to cope with incomplete information. The knowledge acquisition process involved both the elicitation of knowledge directly from experts, and the analysis of construction plans from several past housing developments. The model was implemented on an expert system shell called LEONARDO Level 3, which runs in any standard IBM-PC micro-computer or compatibles. The evaluation of the system focused on the validity of the model, i.e. the degree at which the outcomes of the system resembled the outcomes of the human expertise being modelled in the knowledge base. A prescriptive method of validation was devised specifically for this study, involving both experts that had provided expertise for the system, and external experts.

The study is concerned with the management of refurbishment work within the UK construction industry, from a contractors' perspective. It investigates the main difficulties and problems which managers face in refurbishment work, together with the management skills and knowledge which they need and bring to their work. Management education and training needs of the organisation is also considered. The methodology is a combination of both semi-structured interviews and a postal questionnaire. A total of 142 completed questionnaires from senior, middle and junior managers of 32 large refurbishment (general and specialist) organisations, formed the data base for the quantitative analysis. The quantitative data was augmented by qualitative information derived from semi-structured interviews with 32 training officers and 22 refurbishment managers. Analysis of both quantitative and qualitative data determined the relative degree of difficulty associated with managing refurbishment tasks, and the qualities and attributes associated with successful management of refurbishment projects. It also allowed for the evaluation of management education and training provisions within refurbishment, together with education and training backgrounds of managers. Course duration, location and factors affecting their selection and attendance also received consideration. The major characteristics and difficulties associated with managing refurbishment works have been established. Results of the study show that refurbishment work is complex, highly specialised and contains elements of work which are unique to the refurbishment sector. The educational background of refurbishment managers indicates that majority of refurbishment managers have a trades background, coming through the ranks mainly as joiners and bricklayers. A skills and knowledge inventory for refurbishment management has also been devised. The study also demonstrates that there is little, if any, management courses, inhouse or external, directly geared towards refurbishment. The study recommends that guidelines advocating "how best" to overcome refurbishment problems and difficulties" for different types of refurbishment projects, and refurbishment works across industrial sectors, i.e. defence, hotel and health service sectors, be produced. Similarly, research to establish the core management skills/knowledge associated with successful accomplishment of the various types of refurbishment projects, and refurbishment works across industrial sectors is needed. Further research needs to be conducted on personal qualities and attributes of refurbishment managers who are associated with successful accomplishment of various types of refurbishment projects. Research to establish the extent and degree of involvement of the client, contractor and the rest of the design team, especially refurbishment managers, in carrying out refurbishment work is recommended. Further research to establish management education and training needs of medium and small size refurbishment organisations is suggested. Following the development of a model for postgraduate and continuing professional development (CPD) management education and training programmes, research into "how best" refurbishment management education can be successfully and widely introduced into undergraduate curricular is needed.