The increasing frequency of new product introductions force today's companies to continuously upgrade their production capacities. The frequent revision of production capacities and the capacity loss ...during the reconfiguration period increase the importance of ramp up duration in evaluating capacity investments. This paper aims to explore how a firm should optimally allocate its capacity investments among dedicated manufacturing systems (DMSs), flexible manufacturing systems (FMSs) and reconfigurable manufacturing systems (RMSs) considering the capacity evolution in ramp up period. The proposed model addresses a firm making multiple products for which demand is deterministic and has a specific life cycle. Furthermore, the duration of reconfiguration period is modeled as a function of the amount of capacity change.
This paper presents and analyzes a comprehensive model for the design of cellular manufacturing systems (CMS). A recurring theme in research is a piecemeal approach when formulating CMS models. In ...this paper, the proposed model, to the best of the authors’ knowledge, is the most comprehensive one to date with a more integrated approach to CMS design, where production planning and system reconfiguration decisions are incorporated. Such a CMS model has not been proposed before and it features the presence of alternate process routings, operation sequence, duplicate machines, machine capacity and lot splitting. The developed model is a mixed integer non-linear program. Linearization procedures are proposed to convert it into a linearized mixed integer programming formulation. Computational results are presented by solving some numerical examples, extracted from the existing literature, with the linearized formulation.
Sustainability is increasingly becoming a decisive issue in many aspects of life. While sustainability appears to be a popular research area in general, one cannot observe much emphasis on research ...in design issues of sustainable manufacturing systems presently. In wake of this, this article presents a simultaneous investigation of reconfigurable cellular manufacturing systems (CMSs) and hybrid manufacturing-remanufacturing systems and proposes an integrated approach in design optimization, analysis, and process planning aspects as an attempt to address to a number of design issues for “sustainable manufacturing systems.” A mixed integer linear programming (MILP) model, which considers a classical cell formation problem in CMSs, bridged with a production planning problem, in hybrid manufacturing-remanufacturing systems, while addressing to “reconfiguration” issues for the CMS for different production periods, has been developed. Numerical examples are provided. A detailed discussion of a numerical example is presented to illustrate the proposed model.
Most of the supply chain order management decision making models proposed in the literature are based mainly on the material flow and capacity constraints without any consideration to the ...profitability factor. In this paper, we develop a multi-objective mixed-integer programming (MIP) model which considers profitability in order to effectively manage order acceptance decisions in supply chains, subject to capacity constraints by using activity-based costing (ABC). While there are a numbers of decision-making models in literature integrating ABC in supply chains, this study expands the previous models with a more customer-oriented approach. The proposed model fulfils a desirable amount of orders completely and accepts selective number of orders partially with an objective of minimising the amount of residual capacity and increasing the profitability.
This article proposes one further step toward the design of Sustainable Manufacturing Enterprise. This article presents an integrated approach for designing a reverse logistics network by minimizing ...the carbon emissions and the transportation distances between different candidate centers while considering several system design and operational issues of a Hybrid Manufacturing-Remanufacturing System operating within the above-mentioned reverse logistics network. Accordingly, the article attempts to integrate various sustainability aspects indoctrinated in the
Sustainable Manufacturing
philosophy. In view of this, a mixed integer programming model for designing a reverse logistics network is developed. The model considers the carbon foot print, facility location, and the material flow aspects of the reverse logistics network; in which a hybrid manufacturing-remanufacturing system is integrated. A detailed discussion of a numerical example is presented to illustrate the proposed model. The model has potential applications for supply chain managers designing a reverse logistics networks as well as for production managers at the operations level.
•We incorporate the ramp-up characteristics in capacity planning decisions.•We model the ramp-up duration and partial capacity loss.•We examine the tradeoff between response speed and customer ...service level.
The objective of this paper is to investigate the optimal allocation of capacity investments at the tactical decision-making level by incorporating the configuration characteristics of selected system alternatives comprising Dedicated Manufacturing Systems (DMS) and Reconfigurable Manufacturing Systems (RMS). Particularly, sequencing of stages in a series or a parallel configuration impacts the responsiveness in addressing capacity change requirements. We analyze what type of configuration is more suitable for a manufacturer in terms of service level and cost. We propose a mixed integer programming model by incorporating various ramp-up time patterns, which define system scalability lead time. By solving the MIP model to optimality, we aim to see how capacity is allocated to RMS and DMS based on system cost, system responsiveness, and reconfiguration speed. A discrete event simulation model is used to validate the MIP results under uncertain demand scenarios.
Due to the stringent awareness toward the preservation and resuscitation of natural resources and the potential economic benefits, designing sustainable manufacturing enterprises has become a ...critical issue in recent years. This presents different challenges in coordinating the activities inside the manufacturing systems with the entire closed-loop supply chain. In this paper, a mixed-integer mathematical model for designing a hybrid-manufacturing-remanufacturing system in a closed-loop supply chain is presented. Noteworthy, the operational planning of a cellular hybrid manufacturing-remanufacturing system is coordinated with the tactical planning of a closed-loop supply chain. To improve the flexibility and reliability in the cellular hybrid manufacturing-remanufacturing system, alternative process routings and contingency process routings are considered. The mathematical model in this paper, to the best of our knowledge, is the first integrated model in the design of hybrid cellular manufacturing systems which considers main and contingency process routings as well as reliability of the manufacturing system.
The design of a supply chain network is of great importance as it aims at optimizing costs throughout the supply chain. Traditionally, this optimization has considered operations related costs such ...as sourcing, production, transportation, inventory at each site in the network. Quality related costs were either ignored or considered indirectly. In a previous work, we showed how Cost of Quality (COQ) functions can be used as a viable indicator of the level of quality at each site and integrated in supply chain network design (SCND) models. This results in a non-linear MIP model, which poses challenges to solve. In this work, we develop a gradient-search based solution procedure to solve the model effectively for practical implications. The integration of COQ functions allows managers to explicitly consider the maturity levels of both internal sites (plants) and external partners such as suppliers or subcontractors. More importantly, it can be used as an additional metric by which the partners are measured during the annual evaluation process to see if they have progressed in their maturity levels, i.e. in mastering the costs of quality. COQ also opens a new avenue of research in SCND as the model and hence the solution procedure will vary based on the different ways COQ functions are incorporated in the model.
The traditional capacitated warehouse location problem consists of determining the number and the location of capacitated warehouses on a predefined set of potential sites such that the demands of a ...set of customers are met. A very common assumption made in modeling this problem in almost all of the existing research is that the total capacity of all potential warehouses is sufficient to meet the total demand. Whereas this assumption facilitates to define a well‐structured problem from the mathematical modeling perspective, it is in fact restrictive, not realistic, and hence rarely held in practice. The modeling approach presented in this paper breaks away from the existing research in relaxing this very restrictive assumption. This paper therefore investigates the generalized problem of locating warehouses in a supply chain setting with multiple commodities with no restriction on the total capacity and the demand. A new integer programming formulation for this problem is presented, and an algorithm based on Lagrangean relaxation and decomposition is described for its solution. Three Lagrangean heuristics are proposed. Computational results indicate that reasonably good solutions can be obtained with the proposed algorithms, without having to use a general purpose optimizer.
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