38 documents found, page 1 of 4
Material flow control in make-to-stock production systems: an assessment of ord...
Thürer, Matthias; Fernandes, Nuno O.; Lödding, Hermann; Stevenson, MarkMaterial Flow Control (MFC) is a key element of production planning and control. The literature typically categorizes different MFC methods according to how material flow control is realized. This distinction overlooks that MFC decisions can be subdivided into three independent tasks that are executed as orders progress through the system: (i) order generation, (ii) order release, and (iii) production authoriza...
Comparative analysis of Multicriteria Decision‐Making methods for bus washing p...
Ávila, Paulo; Mota, Alzira; Oliveira, Eliana; Castro, Hélio; Ferreira, Luís Pinto; Bastos, João; Fernandes, Nuno O.; Moreira, JoaquimWater is at the core of sustainable development, and its use for human activities, including vehicle washing, should be done in a sustainable way. There are several technical solutions for washing buses offering different performances, making it difficult to choose the one that best meets the requirements of each specific case. The literature on the topic hardly analyzes the choice of the best technical solutio...
DDMRP relative priority for production execution: an assessment by simulation
Fernandes, Nuno O.; Thürer, Matthias; Silva, Sílvio do CarmoDemand-Driven Material Requirements Planning (DDMRP) was designed to improve supply chain performance in complex and uncertain environments. Literature on the topic suggests that production replenishment orders should be dispatched for execution based on the buffers’ penetration ratio of the products ordered, which is a measure of protection against stock depletion. However, the actual performance impact of thi...
Industry 4.0 in the automotive sector: development of a decision support tool f...
Bessa, Ruben; Ferreira, Luís Pinto; Fernandes, Nuno O.; Ávila, Paulo; Ramos, Ana L.The concept of Industry 4.0 promises to transversally revolutionise industries. Simulation, as one of the main pillars of Industry 4.0, allows improvements in the organisational and production processes of companies. This research work develops a decision support tool based on system dynamics, that address the problem of car dealership sales forecast and evolution depending on the commercial strategies adopted....
Demand driven material requirements planning: using the buffer status to schedu...
Fernandes, Nuno O.; Guedes, Nelson; Thürer, Matthias; Ferreira, Luís Pinto; Ávila, Paulo; Silva, Sílvio do CarmoDemand Driven Material Requirements Planning argues that production re-plenishment orders should be scheduled on the shop floor according to the buffers’ on-hand inventory. However, the actual performance impact of this remains largely unknown. Using discrete event simulation, this study com-pares scheduling based on the on-hand inventory, with scheduling based on the inventory net flow position. Results of our...
A simulation study of aircraft boarding strategies
Moreira, Hélio; Ferreira, Luís Pinto; Fernandes, Nuno O.; Silva, Francisco J.G.; Ramos, Ana L.; Ávila, PauloTo ensure the safety of passengers concerning virus propagation, such as COVID-19, and keep the turnaround time at low levels, airlines should seek efficient aircraft boarding strategies in terms of both physical distancing and boarding times. This study seeks to analyze the impact of different boarding strategies in the context of the International Air Transport Association’s recommendations during the pandemi...
Planeamento e controlo da produção em ambientes dinâmicos : DDMRP
Fernandes, Nuno O.; Silva, Sílvio do CarmoFlexibilidade, eficiência e eficácia ao nível da atividade produtiva são importantes vantagens competitivas para as empresas industriais responderem à volatilidade dos mercados atuais. Os sistemas tradicionais de Planeamento e Controlo da Produção, ainda largamente usados na indústria, não foram desenvolvidos para operar adequadamente neste contexto. A abordagem recentemente proposta, conhecida como Demand-Driv...
Improving urgency-based backlog sequencing of jobs: an assessment by simulation
Fernandes, Nuno O.; Thürer, Matthias; Stevenson, Mark; Carmo-Silva, S.When order release is applied, jobs are withheld in a backlog from where they are released to meet certain performance targets. The decision that selects jobs for release is typically preceded by a sequencing decision. It was traditionally assumed that backlog sequencing is only responsible for releasing jobs on time, whereas more recent literature has argued that it can also support load balancing. Although th...
POLCA Control in Two-Stage Production Systems
Fernandes, Nuno O.; Thürer, Matthias; Mirzaei, Nima; Ferreira, Luís Pinto; Silva, Francisco J. G.; Carmo-Silva, SílvioPOLCA (Paired-cell Overlapping Loops of Cards with Authorization) is a decision support system for material flow control under Quick Response Manufacturing. It operates in the context of low-volume, high-mix, and cellular manufacturing. While there is an increasing literature on POLCA performance, current studies usually assume full availability of components (or parts) at assembly stations, neglecting parts ma...
Workload control and optimised order release: an assessment by simulation
Fernandes, Nuno O.; Thürer, Matthias; Pinho, Tatiana; Torres, Pedro; Silva, Sílvio do CarmoAn important scheduling function of manufacturing systems is controlled order release. While there exists a broad literature on order release, reported release procedures typically use simple sequencing rules and greedy heuristics to determine which jobs to select for release. While this is appealing due to its simplicity, its adequateness has recently been questioned. In response, this study uses an integer li...