The implementation of lean manufacturing concepts has shown significant impacts on various industries. Numerous tools and techniques have been developed to tackle specific problems in order to eliminate wastes and carry out lean concepts. With the focus on "how to make a system leaner," little effort has been made on determining "how lean the system is." Lean assessment surveys evaluate the current status of a system qualitatively against predefined lean indicators. Lean metrics are developed to quantify performance of improvement initiatives, but each metric only focuses on one specific area. Value Stream Maps demonstrate the current and future states graphically with the emphasis on time-based performance only. A truly quantitative and synthesized measure for overall leanness has not been established. In some circumstances, being lean may not be the only goal for manufacturers. In order to compete in the rapidly changing marketplace, manufacturing systems should also be agile to respond quickly to uncertain demands. Nevertheless, being extremely agile may increase the cost of regular operations and reduce the leanness of the system. Similarly, being extremely lean may reduce flexibility and lower the agility level. Therefore, a manufacturing system should be agile enough to handle the uncertainty of demands and meanwhile be lean enough to deliver goods with competitive prices and lead time. In order to achieve the appropriate leanness level, a leanness measure is needed to address not only "how lean the system is" but also "how lean it should be." In this research, a methodology is proposed to quantitatively measure leanness level of manufacturing systems using the Data Envelopment Analysis (DEA) technique. The production process of each work piece is defined as a Decision Making Unit (DMU) that transforms inputs of Cost and Time into output Value. Using a Slacks-Based Measure (SBM) model, the DEA-Leanness Measure is developed to quantify the leanness level of each DMU by comparing the DMU against the frontier of leanness. A Cost-Time-Value analysis is developed to create virtual DMUs to push the frontier towards ideal leanness so that an effective benchmark can be established. The DEA-Leanness Measure provides a unit-invariant leanness score valued between 0 and 1, which is an indication of "how lean the system is" and also "how much leaner the system can be." With the help of Cost-Time Profiling technique, directions of potential improvement can be identified by comparing the profiles of DMUs with different leanness scores. The leanness measure can also be weighted between Cost, Time and Value variables. The weighted DEA-Leanness Measure provides a way to evaluate the impacts of improvement initiatives with an emphasis on the company's strategic focus. Performing the DEA-Leanness measurement requires detailed cost and time data. A Web-Based Kanban is developed to facilitate automated data collection and real-time performance analysis. In some circumstances where detailed data is not readily available but a Value Stream Maps (VSM) has been constructed, the applications of DEA-Leanness Measure based on existing VSM are explored. Besides pursuing leanness, satisfying a customer's demand pattern requires certain level of agility. Based on the DEA-Leanness Measure, appropriate leanness targets can be identified for manufacturing systems considering sufficient agility level. The Online-Delay and Offline-Delay Targets are determined to represent the minimum acceptable delays considering inevitable waste within and beyond a manufacturing system. Combining the two targets, a Lean-Agile Performance Index can then be derived to evaluate if the system has achieved an appropriate level of leanness with sufficient agility for meeting the customers' demand. Hypothetical cases mimicking real manufacturing systems are developed to verify the proposed methodologies. An Excel-based DEA-Leanness Solver and a Web-Kanban System have been developed to solve the mathematical models and to substantiate potential applications of the leanness measure in real world. Finally, future research directions are suggested to further enhance the results of this research. / Ph. D.

A tendência de aumento de mix e redução do ciclo de vida de produtos está se ampliando em diversos setores da economia e a imprevisibilidade de demanda resultante gera novos desafios para o gerenciamento da cadeia de suprimentos que deve buscar maximizar a disponibilidade dos produtos ao mesmo tempo em que a sobra é minimizada. Apesar dessa tendência ainda não estar consolidada, a relevância de setores que já enfrentam esses desafios (principalmente as indústrias relacionados à moda e à tecnologia) e a importância da adequação dos processos da empresa a esse novo ambiente para a lucratividade do negócio constituem os motivadores dessa pesquisa. Dessa forma, o principal objetivo deste trabalho é identificar quais práticas de melhoria de manufatura podem ser utilizadas para lidar com os desafios inerentes a esse ambiente. Além disso, propõe-se caracterizar tais desafios formalmente, explicitando mais detalhadamente a relação entre eles, às práticas de manufatura e alguns resultados operacionais e financeiros das empresas. Para isso são utilizadas a revisão bibliográfica e a pesquisa-ação em uma indústria de vestuário de moda como os dois principais procedimentos técnicos de pesquisa. Os resultados positivos obtidos permitem concluir que práticas de melhoria provenientes da manufatura enxuta e da manufatura ágil podem ser utilizadas em conjunto para adequar o processo de planejamento e produção aos desafios desse novo cenário, permitindo a obtenção de melhores resultados operacionais. / The trend of increased mix and shorter product life cycle is expanding in several sectors of the economy and the resulting demand unpredictability generates new challenges for the supply chain management, which needs to find new ways to maximize products availability and minimize inventory obsolescence. Despite this trend is not yet consolidated, the relevance of sectors already facing this challenges (especially industries related to fashion and technology) and the importance of processes adaptation to this new environment for business profitability are the motivators of this research. Thus, the main objective of this work is to identify which manufacturing improvement techniques can be used to deal with this environment challenges. Furthermore, it is proposed to formally characterize those challenges, explaining in more detail the relationship between them, the manufacturing practices and some operational and financial results of companies. To achieve this goal, literature review and action research in a fashion apparel industry are used as the two main research procedures. The positive results obtained indicate that improvement practices from lean manufacturing and agile manufacturing can be used together to tailor production and the planning process to this new scenario, allowing for better operational results.

A tendência de aumento de mix e redução do ciclo de vida de produtos está se ampliando em diversos setores da economia e a imprevisibilidade de demanda resultante gera novos desafios para o gerenciamento da cadeia de suprimentos que deve buscar maximizar a disponibilidade dos produtos ao mesmo tempo em que a sobra é minimizada. Apesar dessa tendência ainda não estar consolidada, a relevância de setores que já enfrentam esses desafios (principalmente as indústrias relacionados à moda e à tecnologia) e a importância da adequação dos processos da empresa a esse novo ambiente para a lucratividade do negócio constituem os motivadores dessa pesquisa. Dessa forma, o principal objetivo deste trabalho é identificar quais práticas de melhoria de manufatura podem ser utilizadas para lidar com os desafios inerentes a esse ambiente. Além disso, propõe-se caracterizar tais desafios formalmente, explicitando mais detalhadamente a relação entre eles, às práticas de manufatura e alguns resultados operacionais e financeiros das empresas. Para isso são utilizadas a revisão bibliográfica e a pesquisa-ação em uma indústria de vestuário de moda como os dois principais procedimentos técnicos de pesquisa. Os resultados positivos obtidos permitem concluir que práticas de melhoria provenientes da manufatura enxuta e da manufatura ágil podem ser utilizadas em conjunto para adequar o processo de planejamento e produção aos desafios desse novo cenário, permitindo a obtenção de melhores resultados operacionais. / The trend of increased mix and shorter product life cycle is expanding in several sectors of the economy and the resulting demand unpredictability generates new challenges for the supply chain management, which needs to find new ways to maximize products availability and minimize inventory obsolescence. Despite this trend is not yet consolidated, the relevance of sectors already facing this challenges (especially industries related to fashion and technology) and the importance of processes adaptation to this new environment for business profitability are the motivators of this research. Thus, the main objective of this work is to identify which manufacturing improvement techniques can be used to deal with this environment challenges. Furthermore, it is proposed to formally characterize those challenges, explaining in more detail the relationship between them, the manufacturing practices and some operational and financial results of companies. To achieve this goal, literature review and action research in a fashion apparel industry are used as the two main research procedures. The positive results obtained indicate that improvement practices from lean manufacturing and agile manufacturing can be used together to tailor production and the planning process to this new scenario, allowing for better operational results.

A challenge in Lean Construction is how to make it applicable when there is a high degree of complexity and uncertainty. In many construction projects there are changing project requirements, unique products and a need for actions that are highly focused on meeting customer/client expectations. Such scenarios require management methods that are characterised by being flexible and able to react to change. The aim of this thesis is to introduce a method that has such characteristics. Project Management, Lean and Agile paradigms are merged through the application of the fission and fusion approach of nuclear physics. This research is facilitated through a sequential explorative method. In the first instance, interviews with 22 practitioners in the fields of construction project management, Lean and Agile have been conducted. Then a quantitative self-administered questionnaire with 213 useful responses has been utilised to validate the transferability of the interview findings. It is concluded that Lean is not ideally suited to dealing with the dynamic nature of construction projects. Agile methods, which were developed to cope with the high levels of uncertainty inherent to IT projects, are more flexible and able to react to change. Hence utilising Agile-based methods might be the key to the successful utilization of Lean in construction. Therefore a management method based on combining Lean and Agile approaches has potential. Such an approach needs creative thinking to develop a solution that is different to that of “Leagile”. Leagile uses Lean and Agile methods in the execution phase sequentially, through using a decoupling point model to separate the two. This thesis introduces a new paradigm in which such a decoupling or separation does not take place. Rather, project management, Lean and Agile have been merged together to develop a new holistic and strategic framework. The paradigm presented in this thesis is termed “AgiLean Project Management”.

As the Army transitions to the Army Force Generation (ARFORGEN) deployment cycle, it must adjust its many operations in support of ARFORGEN. Specifically, the Initial Military Training (IMT) must be able to adjust the scheduling of its classes for newly enlisted service members to finish training such that they fulfill Brigade Combat Team (BCT) requirements within their common due windows. We formulate this problem as a lot streaming problem. Lot streaming splits a batch of jobs into sublots,which are then processed over the machines in an overlapping fashion. To schedule classes for the IMT, there are two stages that must be coordinated: Basic Training (BT) and Advanced Individual Training (AIT). For the Army Force Generation problem, the classes are considered as sublots that are streamed from one stage to the next. For this process, the model formulation must address determination of class sizes and scheduling of soldiers and classes at the two stages such that (1) the start times of the soldiers at Stage 2 are greater than their completion times at Stage 1, and (2) the assignment of requisite number of soldiers is made to each BCT, so as to minimize the total flow time. We propose a decomposition-based approach for the solution of this problem. In an effort to decompose the problem, the original lot streaming problem is reformulated such that the master problem selects an optimal combination of schedules for training classes and assigning soldiers to BCTs. A complete schedule selected in the master problem includes the assignments of soldiers to classes in BT, AIT, and their assignments to the BCTs, so as to minimize the total flow time as well as earliness and tardiness for regular Army units. Earliness and Tardiness are defined as the length of the time a soldier waits before and after the due date, respectively, of the BCT to which he or she is assigned. Our decomposition-based method enables solution of larger problem instances without running out of memory, and it affords CPU time reductions when compared with the CPU times required for these problem instances obtained via direct application of CPLEX 12.1. Our investigation into the structure of the problem has enabled further improvement of the proposed decomposition-based method. This improvement is achieved because of a result, which we show, that the first and second-stage scheduling problems need not be solved as one combined subproblem, but rather, they can be solved sequentially, the first stage problem followed by the second stage problem. The combination of Stage 1 and Stage 2 problems as one subproblem creates several additional enumerations of possible schedules the model must generate. By reducing this number of enumerations, the computational effort involved in solving the model reduces significantly, thereby allowing reductions in CPU time. In the Sequential approach, the completion times of soldiers determined at Stage 1 are passed to Stage 2 as bounds on their completion times at Stage 2. We prove that solving the combined subproblem sequentially as two subproblems is optimal when the first stage has no limit on the batch size and the ready times of the soldiers at Stage 1 are the same. For the Army Force Generation problem, we use unequal ready times, and therefore, solving the scheduling problems for the first two stages as sequential subproblems can lead to suboptimal solutions. Our experimental investigation shows efficacy of solving larger-sized problem instances with this method. We also recommend various potential additions to improve the Sequential approach for application to the overall Army problem. We have also demonstrated the use of our methodology to a real-life problem instance. Our methodology results in schedules for IMT with an estimated 28% reduction in mean flow time for soldiers over what is currently experienced in practice. We apply this Sequential approach to various extensions of the problem on hand that pertain to hybrid flow shop and agile manufacturing environments. Results of our computational investigation show the effectiveness of using the Sequential approach over direct solution by CPLEX from the viewpoint of both optimality gap and the CPU time required. In particular, we consider two different model configurations for a hybrid flow shop and three different model configurations for an agile manufacturing facility. / Ph. D.

Current global business competition has resulted in significant challenges for manufacturing and production sectors focused on shorter product lifecyc1es, more diverse and customized products as well as cost pressures from competitors and customers. To remain competitive, manufacturers, particularly in automotive industry, require the next generation of manufacturing paradigms supporting flexible and reconfigurable production systems that allow quick system changeovers for various types of products. In addition, closer integration of shop floor and business systems is required as indicated by the research efforts in investigating "Agile and Collaborative Manufacturing Systems" in supporting the production unit throughout the manufacturing lifecycles. The integration of a business enterprise with its shop-floor and lifecycle supply partners is currently only achieved through complex proprietary solutions due to differences in technology, particularly between automation and business systems. The situation is further complicated by the diverse types of automation control devices employed. Recently, the emerging technology of Service Oriented Architecture's (SOA's) and Web Services (WS) has been demonstrated and proved successful in linking business applications. The adoption of this Web Services approach at the automation level, that would enable a seamless integration of business enterprise and a shop-floor system, is an active research topic within the automotive domain. If successful, reconfigurable automation systems formed by a network of collaborative autonomous and open control platform in distributed, loosely coupled manufacturing environment can be realized through a unifying platform of WS interfaces for devices communication. The adoption of SOA- Web Services on embedded automation devices can be achieved employing Device Profile for Web Services (DPWS) protocols which encapsulate device control functionality as provided services (e.g. device I/O operation, device state notification, device discovery) and business application interfaces into physical control components of machining automation. This novel approach supports the possibility of integrating pervasive enterprise applications through unifying Web Services interfaces and neutral Simple Object Access Protocol (SOAP) message communication between control systems and business applications over standard Ethernet-Local Area Networks (LAN's). In addition, the re-configurability of the automation system is enhanced via the utilisation of Web Services throughout an automated control, build, installation, test, maintenance and reuse system lifecycle via device self-discovery provided by the DPWS protocol.

This thesis is focused on the application of Component-Based (CB) technology to shop floor devices using a Service Oriented Architecture (SOA) and Web Services (WS) for the purpose of realising future generation agile manufacturing systems. The environment of manufacturing enterprises is now characterised by frequently changing market demands, time-to-market pressure, continuously emerging new technologies and global competition. Under these circumstances, manufacturing systems need to be agile and automation systems need to support this agility. More specifically, an open, exible automation environment with plug and play connectivity is needed. Technically, this requires the easy connectivity of hardware devices and software components from different vendors. Functionally, there is a need of interoperability and integration of control functions on different hierarchical levels ranging from field level to various higher level applications such as process control and operations management services. A potential solution is to realise a modular and reconfigurable automation system, based on a platform of reusable components; while simultaneously reducing the number of unique components. For designing such reusable components, a component-based technology has been used in current thesis. The automation components created are active and distributed entities interacting through their data, event and service ports. To communicate these entities, this thesis focuses on applying SOA and WS at device level. SOA and WS have already been proven successful in linking business applications. If SOA can be applied at shop floor using the embedded devices, it can enable entirely new automation architecture based on peer-to-peer interactions between autonomous devices. The adoption of this SOA-WS approach at shop floor level would enable a seamless integration of higher level business applications and shop- floor level system. This will also provide a loosely coupled message-oriented service in embedded device networks and geographically distributed automation system. SOA can be implemented using Web Services on the embedded devices, which will provide even greater exibility and interoperability because WS is platform neutral. This SOA-WS approach will enable end users to operate and maintain the supplied system easily. A key aim of this thesis is to examine if the adoption of SOA-WS at the embedded control devices can provide the same level of message speed and reliability as the current control systems. It is expected that the desired distributed, loosely coupled and reconfigurable automation system can be formed by a network of these collaborative autonomous SOA-WS based devices using an open control platform. This approach has been experimentally evaluated both in terms of quantity and quality using various parameters involved in the design, implementation, evaluation and recon guration of SOA-WS based automation systems. This has been done using the Ford Festo test rig located at the Manufacturing System Integration Research Institute of Loughborough University. The mechanisms on this test rig represent control problems typically associated in engine assembly and handling machines. Therefore, the result of experimental studies performed on this test rig can be considered applicable to real manufacturing applications.

A capacidade de customização de produtos é considerada atualmente um fator de competitividade muito importante para a sobrevivência das empresas. A interferência dos clientes na concepção e na fabricação dos produtos está cada vez mais intensa. Dentre as várias estratégias de customização, a tipologia de produção Engineer to Order (ETO), na qual o cliente é envolvido nas fases de design e desenvolvimento do produto, é considerada a mais complexa e ineficiente. Embora o número de organizações classificadas como ETO seja bastante elevado e os problemas associados a esta tipologia sejam bem conhecidos, não existem registros consolidados na literatura sobre qual é a melhor abordagem de gestão das cadeias produtivas destes ambientes. Além disso, as práticas de gestão sugeridas por alguns pesquisadores consideram a tipologia ETO um sistema homogêneo, no qual todas as empresas recebem as mesmas abordagens. No entanto, dentro do universo ETO existem empresas com diferentes tipos de customização. Algumas empresas fabricam produtos completamente novos, desenvolvidos para clientes específicos. Outras empresas fornecem produtos com estrutura híbrida, na qual alguns componentes são padronizados e outros são customizados. A grande diferença entre os sistemas produtivos ETO exige que cada ambiente receba uma abordagem específica para o seu modelo de negócio. Com o intuito de preencher esta lacuna, o presente trabalho propõe uma classificação da tipologia ETO com recomendações das melhores práticas de manufatura para cada subtipologia ETO definida. A classificação proposta foi baseada em estudos de caso com implementações de projetos de melhoria em diferentes ambientes ETO. / The ability of customizing products is considered a very important competitive factor for the survival of nowadays companies. The power of customers influence on products conception and manufacturing is increasing. Among the various customization strategies, the Engineer to Order (ETO) production typology, in which customers are involved at product design and development stages, is considered the most complex and inefficient. Although there are many organizations classified as ETO and the problems associated with this typology are very known, there is a lack of agreement in literature about the best practices for the value chain management of these environments. Furthermore, the practices suggested by some researchers consider the ETO typology as a homogeneous system where all the companies receive the same approach. However, the companies of the ETO universe show different customization approaches. Some companies produce products completely new and designed for specific customers. Other companies provide products with a hybrid structure which is formed by standardized and customized components. The big difference found between all kinds of ETO production systems implies that specific approaches have to be applied for each business model. In order to fill this gap, this work offers a classification for the ETO typology with some recommendations of the best manufacturing practices for each ETO sub typology defined. The proposed classification was based on cases of improvement projects implemented in different ETO environments.

A capacidade de customização de produtos é considerada atualmente um fator de competitividade muito importante para a sobrevivência das empresas. A interferência dos clientes na concepção e na fabricação dos produtos está cada vez mais intensa. Dentre as várias estratégias de customização, a tipologia de produção Engineer to Order (ETO), na qual o cliente é envolvido nas fases de design e desenvolvimento do produto, é considerada a mais complexa e ineficiente. Embora o número de organizações classificadas como ETO seja bastante elevado e os problemas associados a esta tipologia sejam bem conhecidos, não existem registros consolidados na literatura sobre qual é a melhor abordagem de gestão das cadeias produtivas destes ambientes. Além disso, as práticas de gestão sugeridas por alguns pesquisadores consideram a tipologia ETO um sistema homogêneo, no qual todas as empresas recebem as mesmas abordagens. No entanto, dentro do universo ETO existem empresas com diferentes tipos de customização. Algumas empresas fabricam produtos completamente novos, desenvolvidos para clientes específicos. Outras empresas fornecem produtos com estrutura híbrida, na qual alguns componentes são padronizados e outros são customizados. A grande diferença entre os sistemas produtivos ETO exige que cada ambiente receba uma abordagem específica para o seu modelo de negócio. Com o intuito de preencher esta lacuna, o presente trabalho propõe uma classificação da tipologia ETO com recomendações das melhores práticas de manufatura para cada subtipologia ETO definida. A classificação proposta foi baseada em estudos de caso com implementações de projetos de melhoria em diferentes ambientes ETO. / The ability of customizing products is considered a very important competitive factor for the survival of nowadays companies. The power of customers influence on products conception and manufacturing is increasing. Among the various customization strategies, the Engineer to Order (ETO) production typology, in which customers are involved at product design and development stages, is considered the most complex and inefficient. Although there are many organizations classified as ETO and the problems associated with this typology are very known, there is a lack of agreement in literature about the best practices for the value chain management of these environments. Furthermore, the practices suggested by some researchers consider the ETO typology as a homogeneous system where all the companies receive the same approach. However, the companies of the ETO universe show different customization approaches. Some companies produce products completely new and designed for specific customers. Other companies provide products with a hybrid structure which is formed by standardized and customized components. The big difference found between all kinds of ETO production systems implies that specific approaches have to be applied for each business model. In order to fill this gap, this work offers a classification for the ETO typology with some recommendations of the best manufacturing practices for each ETO sub typology defined. The proposed classification was based on cases of improvement projects implemented in different ETO environments.

El texto completo de este trabajo no está disponible en el Repositorio Académico UPC por restricciones de la casa editorial donde ha sido publicado. / This study proposes a production model that increases the manufacturing capacity in a small and medium-sized enterprise (SME) of garments with an aim to reduce the nonfulfillment of order deliveries. An assessment has been done and waiting times between production processes have been identified, along with defective products and inefficient work methods. This study proposes the design of a lean manufacturing model under the change management approach, whose methodology comprises five phases. In phase 0, awareness and training sessions are conducted (change management). Then, phase 1 reorganizes the work area (plant layout re-distribution and 5S) and phase 2 seeks better workload balances (line balance and Heijunka implementation). Later, phase 3 standardizes work methods (standardization). Finally, the proposed model will be validated to determine whether the selected operating tools are supported by the awareness that contributes to increasing production. © 2021, Springer Nature Switzerland AG. / Revisión por pares