Branch and Price Solution Approach for Order Acceptance and Capacity Planning in Make-to-Order Operations

The increasing emphasis on mass customization, shortened product lifecycles, synchronized supply chains, when coupled with advances in information system, is driving most firms towards make-to-order (MTO) operations. Increasing global competition, lower profit margins, and higher customer expectations force the MTO firms to plan its capacity by managing the effective demand. The goal of this research was to maximize the operational profits of a make-to-order operation by selectively accepting incoming customer orders and simultaneously allocating capacity for them at the sales stage. For integrating the two decisions, a Mixed-Integer Linear Program (MILP) was formulated which can aid an operations manager in an MTO environment to select a set of potential customer orders such that all the selected orders are fulfilled by their deadline. The proposed model combines order acceptance/rejection decision with detailed scheduling. Experiments with the formulation indicate that for larger problem sizes, the computational time required to determine an optimal solution is prohibitive. This formulation inherits a block diagonal structure, and can be decomposed into one or more sub-problems (i.e. one sub-problem for each customer order) and a master problem by applying Dantzig-Wolfe’s decomposition principles. To efficiently solve the original MILP, an exact Branch-and-Price algorithm was successfully developed. Various approximation algorithms were developed to further improve the runtime. Experiments conducted unequivocally show the efficiency of these algorithms compared to a commercial optimization solver. The existing literature addresses the static order acceptance problem for a single machine environment having regular capacity with an objective to maximize profits and a penalty for tardiness. This dissertation has solved the order acceptance and capacity planning problem for a job shop environment with multiple resources. Both regular and overtime resources is considered. The Branch-and-Price algorithms developed in this dissertation are faster and can be incorporated in a decision support system which can be used on a daily basis to help make intelligent decisions in a MTO operation

Hierarchical Multi-Project Planning and Supply Chain Management: an Integrated Framework

This work focuses on the need for new knowledge to allow hierarchical multi-project management to be conducted in the construction industry, which is characterised by high uncertainty, fragmentation, complex decisions, dynamic changes and long-distance communication. A dynamic integrated project management approach is required at strategic, tactical and operational levels in order to achieve adaptability. The work sees the multi-project planning and control problem in the context of supply chain management at main contractor companies. A portfolio manager must select and prioritise the projects, bid and negotiate with a wide range of clients, while project managers are dealing with subcontractors, suppliers, etc whose relationships and collaborations are critical to the optimisation of schedules in which time, cost and safety (etc) criteria must be achieved. Literature review and case studies were used to investigate existing approaches to hierarchical multi-project management, to identify the relationships and interactions between the parties concerned, and to investigate the possibilities for integration. A system framework was developed using a multi-agent-system architecture and utilising procedures adapted from literature to deal with short, medium and long-term planning. The framework is based on in-depth case study and integrates time-cost trade-off for project optimisation with multi-attribute utility theory to facilitate project scheduling, subcontractor selection and bid negotiation at the single project level. In addition, at the enterprise level, key performance indicator rule models are devised to align enterprise supply chain configuration (strategic decision) with bid selection and bid preparation/negotiation (tactical decision) and project supply chain selection (operational decision). Across the hierarchical framework the required quantitative and qualitative methods are integrated for project scheduling, risk assessment and subcontractor evaluation. Thus, experience sharing and knowledge management facilitate project planning across the scattered construction sites. The mathematical aspects were verified using real data from in-depth case study and a test case. The correctness, usefulness and applicability of the framework for users was assessed by creating a prototype Multi Agent System-Decision Support System (MAS-DSS) which was evaluated empirically with four case studies in national, international, large and small companies. The positive feedback from these cases indicates strong acceptance of the framework by experienced practitioners. It provides an original contribution to the literature on planning and supply chain management by integrating a practical solution for the dynamic and uncertain complex multi-project environment of the construction industry

Analysing the implementation of a material requirements planning (MRP) system into an engineer-to-order (ETO) company ; the case of National Oilwell Varco Norway (NOVN)

Masteroppgave økonomi og administrasjon- Universitetet i Agder, 2014A material requirements planning (MRP) system is a computer-based planning and control system whose main objectives are to provide the right part at the right time, and to meet the schedules for completed products. The development of these systems revolutionised the manufacturing industry, and lead to it being adopted by many companies. The expectations of the systems were high, both from academia and industry in the subject area of production planning and control. However, the widespread use of the system has uncovered several failures, mainly because the systems are implemented under the assumption that “one-size-fits-all”, and thus do not differentiate between various operations strategies. Prior research has already identified MRP systems as successful production planning and control systems in several operations strategies. Despite its importance, the previous research on MRP systems has not thoroughly addressed the systems strategic fit with an engineer-to-order (ETO) operations strategy. This thesis therefore focuses on the use of an MRP system in an ETO environment, and the overall objective is to investigate if implementation of an MRP system supports the operations strategy of an ETO company. To help investigate the overall objective, a literature review and a case study has been conducted. The literature review was carried out to provide a theoretical base for the research and a foundation for the future work of the research. A case study was conducted to help get a better understanding of an MRP system’s strategic fit in an ETO company to draw parallels between theory and practice. Numerical data has been collected to conduct statistical analysis. The case study company is a large ETO company that is about to implement an MRP system and that previously have used a similar system in some of its departments. Qualitative data from the case study have mainly been conducted through interviews and informal conversations with key informants employed in the case study company. The result of this research shows that there is a clear misalignment between the decision support provided by an MRP system and the decision support required by an ETO company. The product-, market- and process characteristics of an ETO company are too much of a constraining factor for the MRP system, which may lead to reduced competitiveness. Furthermore, the research suggests that organisational factors, such as education level of employees, company size and culture have significant impacts on implementation of an MRP system. The results gathered from the research have a foundation from relevant theory, which strengthens the quality of the thesis. The thesis has therefore contributed with increased knowledge and provides a better understanding of the use of an MRP system in an ETO company. In particular the definitions in the thesis, the identified variables, and the frameworks should be of interest for researchers, management, and consultant in the area of production planning and control (PPC). The research also has important implications for top management and policy makers in implementing an MRP system, as these stakeholders need to communicate effectively with their organisation about their MRP adoption intentions. Case study findings suggest that MRP systems are not suitable for ETO products, and that MRP implementation is influenced by, but not necessarily bound by, existing national and organisational factors. The findings of this study aid the management of organisations that are implementing MRP systems to gain a better understanding of the likely challenges they may face and enables them to put in place appropriate measures to mitigate the risk of implementation failures

Proceedings of the inaugural construction management and economics ‘Past, Present and Future’ conference CME25, 16-18 July 2007, University of Reading, UK

This conference was an unusual and interesting event. Celebrating 25 years of Construction Management and Economics provides us with an opportunity to reflect on the research that has been reported over the years, to consider where we are now, and to think about the future of academic research in this area. Hence the sub-title of this conference: “past, present and future”. Looking through these papers, some things are clear. First, the range of topics considered interesting has expanded hugely since the journal was first published. Second, the research methods are also more diverse. Third, the involvement of wider groups of stakeholder is evident. There is a danger that this might lead to dilution of the field. But my instinct has always been to argue against the notion that Construction Management and Economics represents a discipline, as such. Granted, there are plenty of university departments around the world that would justify the idea of a discipline. But the vast majority of academic departments who contribute to the life of this journal carry different names to this. Indeed, the range and breadth of methodological approaches to the research reported in Construction Management and Economics indicates that there are several different academic disciplines being brought to bear on the construction sector. Some papers are based on economics, some on psychology and others on operational research, sociology, law, statistics, information technology, and so on. This is why I maintain that construction management is not an academic discipline, but a field of study to which a range of academic disciplines are applied. This may be why it is so interesting to be involved in this journal. The problems to which the papers are applied develop and grow. But the broad topics of the earliest papers in the journal are still relevant today. What has changed a lot is our interpretation of the problems that confront the construction sector all over the world, and the methodological approaches to resolving them. There is a constant difficulty in dealing with topics as inherently practical as these. While the demands of the academic world are driven by the need for the rigorous application of sound methods, the demands of the practical world are quite different. It can be difficult to meet the needs of both sets of stakeholders at the same time. However, increasing numbers of postgraduate courses in our area result in larger numbers of practitioners with a deeper appreciation of what research is all about, and how to interpret and apply the lessons from research. It also seems that there are contributions coming not just from construction-related university departments, but also from departments with identifiable methodological traditions of their own. I like to think that our authors can publish in journals beyond the construction-related areas, to disseminate their theoretical insights into other disciplines, and to contribute to the strength of this journal by citing our articles in more mono-disciplinary journals. This would contribute to the future of the journal in a very strong and developmental way. The greatest danger we face is in excessive self-citation, i.e. referring only to sources within the CM&E literature or, worse, referring only to other articles in the same journal. The only way to ensure a strong and influential position for journals and university departments like ours is to be sure that our work is informing other academic disciplines. This is what I would see as the future, our logical next step. If, as a community of researchers, we are not producing papers that challenge and inform the fundamentals of research methods and analytical processes, then no matter how practically relevant our output is to the industry, it will remain derivative and secondary, based on the methodological insights of others. The balancing act between methodological rigour and practical relevance is a difficult one, but not, of course, a balance that has to be struck in every single paper

How to Make the Most Productive Intervention in a Complex Economic System

Information about supply and demand propagates through supply chains in a queueing network with people and computers as batch information processors. As each batch processor delays propagation of information whilst pursuing optimal local decisions, the effect is delay and distortion of the information that is used to commit resources to actions in the supply chain. This thesis investigates the effect of delay and imperfect information as a source of error, to establish the case for change in research focus from optimal exploitation of physical constraints to optimal exploitation of information. In the context of real world supply chains, the thesis asks "How does one make the most productive intervention in a complex economic system?" and pursues a meta-intervention which perpetually minimises the discovered error-term. Evidence from literature indicates that agent-based modelling permits real-time peer-to-peer communication and distributed optimisation. Based on the literature the research project designs and develops an agent-based model which operates in real-time without batch-processes and can perform incremental multi-objective optimisation under realistic (chronologically progressive) conditions for decision making. The agent based model is then used to investigate two real-world supply chains, as case studies, which reveals a significant improvement of profitability and order-fulfilment. The thesis concludes that agent-based modelling is a very promising direction for "making the most productive intervention" as it reduces delay to a minimum. Finally it recommends that continuous improvement of decision making methods is a role better suited for humans, rather than operational decision making where computers cope much better with the high amount of detailed information

Merchant banks and corporate acquisitions

The aim of this dissertation is to provide a comprehensive analysis of how British merchant banks organise and approach contested bids within the institutional framework of the City.To this end., a number of exploratory hypotheses were derived from a pilot study with five merchant banks in the City as well as discussions with the project supervisor. Interviews were the carried out with 30 leading UK merchant banks belonging to either the Accepting or Issuing houses associations regarding their role, organisational structure, approaches to bidding and defensive issues related to contested bids. The main perceptions and empirical findings from this major survey are then compared with results to analysis of 30 case studies spanning the 1979-81 period (supported by analysis of another 10 cases with respect to some issues)and the results are then discussed and analysed in chapters 8 and 9. To obtain an overview: of how self regulation prescribes bid behaviour and practices, interviews were also held with various City bodies. Volume 1 of this dissertation is divided into 5 parts. Part i outlines the research objectives, methodology and literature survey. Part II then examines the results of a survey of opinion of merchant bankers. In Part III, main results of the literature survey and merchant banking field work are compared with evidence derived . from the case studies. Important research findings pertaining to organisational structure of leading UK merchant banks, approaches to strategies and related issues are then identified and highlighted. Contemporary takeover issues which became apparent during this research project are then analysed and possible reforms suggested (Part IV). The final section i.e., Part V considers some for corporate advisory work relating to takeovers in the 1980s. In the discussion, details of 40 case studies are used to illustrate the main trends. Volume 2, which is not to be generally available to readers gives a cross section of'transcripts of the interviews held with more than 90 merchant bankers, stockbrokers, takeover specialists, American investment bankers, merchant banking analysts, authors, foreign were chant bankers, officials of self-regulatory bodies as well as relevant financial and non-financial data of the merchant banks interviewed during this survey, Findings of this study are numerous and it has illustrated the fact that UK merchant banks approached their takeover assignments through team work with a minimum of 2, a favored norm of 3 and the maximum team size is dependent on the size, time factor and complexity of the transaction itself. Their approach to contested bids which are invariably multi-disciplinary and complicated should not be viewed purely from the financial perspective alone. In both bidding and defending capacities, the merchant subscribe to the hypotheses that while there are general financial and non-financial principles guiding their approaches,flexibility and creativity are essential. Although the bidder has more control over timing in the takeover Did, however, the findings of this survey have shown that in a number of cases, this factor [nay not always favour the buyer because of the emergence of rival bidders. *Moreover . timing is but one element of a bidding/offensive strategy. In essence, the defensive posture is necessarily a response appropriate to the offensive strategy. The share ownership structure of the defending company plays a crucial role in the final outcome of the bid. Generally, the merchant banks perceive that it is relatively easier to defend a client when the ownership is spread amongst the small investors who are thought to be more loyal to their boards. This is particularly important, for the main defensive thrust is often an appeal to shareholders' loyalty. This is but one aspect of defensive strategies for, although the literature of corporate finance tends to dwell on. only a few defensive strategies, this study finds that their range is wide. Another important finding was the fact that UK stockbrokers (as agents) work very closely with the merchant banks ('as principals) in advising on contested bids. The former are normally consulted for their market expertise. One of the leading stockbroking firms interviewed served 8 of the 17 ACH (Accepting Houses Committee) members. Owing to this special relationship between these two types of financial institutions and possibly their lack of financial power comparable to that of the merchant banks, the stockbrokers are generally constrained from acting as prinicpal advisors in takeover situations. However, with the impending structural changes in the stockbroking business in the mid 1980s, there is a possibility that either the merchant bank or stockbroking firm assuming dual capacity. Finally, UK merchant banks in the 1980s will be characterised by a trend towards conglomeracy and the development of fee-based international merchant banking activities especially in the USA and. the Asia/Pacific regions in view of the constriction and competition in domestic corporate financial advisory activities

Exploratory analysis of a systemic approach to study supply chain integration potential in the UK offshore wind industry

Emphasis has been placed on supply chain management (SCM) and supply chain integration (SCI) within the offshore wind (OSW) industry in the United Kingdom (UK). The UK government has shown an interest in developing a technologically advanced, skilful, and competitive domestic supply chain with the potential to support future OSW developments around the UK coast. The need to develop a more cost-effective and collaborative OSW supply chain has introduced the concept of SCI into discussions of the OSW industry. Notwithstanding the importance of SCM and SCI in the UK OSW industry, and despite the widespread use of these terms within the industry, little has been done to explain these concepts in relation to the context of OSW. The purpose of this thesis is to address this limitation by providing more detailed description of the OSW supply chain from a theoretical standpoint by empirically exploring SCI in the OSW industry to build a greater understanding of the nature and potential of SCI in the OSW. This research focuses on the development and construction phases of ‘fixed bottom’ OSW farms in the UK. Based on the existing SCM and project-based SCM literature, this thesis provides discussion of the OSW supply chain. The thesis also explores the literature on SCI and systems thinking to form a foundation for an empirical study of SCI in the OSW industry. It applies a systems thinking approach called the Viable System Model (VSM) to qualitatively explore the nature and potential of SCI in the OSW supply chain. This research draws upon Espinosa and Walker’s (2017) suggested ‘methodology to support self-transformation’ as a guideline for the application of the VSM, and conducts interviews with representatives of the OSW supply chain for the collection of primary data. The thesis proposes two SCI strategies based on the VSM; the ‘viable SCI strategy’ and the ‘strategic cluster integration strategy’, which demonstrate the potential of SCI within the OSW industry, including what improvements could be made to facilitate the performance of the whole supply chain. The research findings provide insights into the current nature of SCI within the OSW industry, ultimately suggesting that SCI is largely dependent upon the different approaches taken by OSW project developers when managing supply chains. In addition, this research identifies several facilitating and inhibiting factors of SCI. This thesis contributes to the existing body of knowledge by introducing a VSM inspired framework for the analysis of SCI within project-based environments. Furthermore, it proposes SCI strategies to show how OSW supply chains can be integrated and what improvements could be achieved as a result

Essays in applied microeconomic theory: crime and defence

The first part of this thesis is concerned with tax competition when the tax receipts fund an anti-crime measure. Both the capital and criminals are mobile between two jurisdictions. The resulting pure strategy Nash equilibrium tax rates are distorted from the optimal tax by the equilibrium migration response of the rich; if positive at the equilibrium then tax competition will result in taxes that are too high whilst if it is negative taxes will be too low compared to the optimum. The best response functions of the model are tested using data from England and Wales. The possibility that they engage in tax competition cannot be ruled out. It is possible for a central government to devolve tax raising powers without the distortion occurring if they can impose an optimal sanction. This, though, is independent of the harm caused by the crime and could be politically difficult to introduce. The second part looks at the Ministry of Defence’s procurement policy since 1985. The role of competition has increased but scant attention was played to the trade-off between maximising the benefits of current competition and obtaining future competition. The Ministry of Defence always chose to take the benefits in the short term arguing any loss of competition merely eliminated excess capacity which the Ministry of Defence would no longer have to pay for. Whilst the empirics suggest this is true during the 1990s, the problems encountered on the Type 45 project at the start of the millennium demonstrate the difficulties they have in procuring given the limited number of domestic firms they can contract with. An alternative mechanism of directed buys, with recourse to a competitive market off the equilibrium path, is suggested as a way in which the Ministry of Defence can preserve competition into the future