Analysis of operating policies for manufacturing cells

Problem definition: Merchant commodity and energy production assets operate in markets with volatile prices and exchange rates. Plant closures adversely affect societal entities beyond the specific plant being shut down, such as the parent company and the local community. Motivated by an aluminum producer, we study if mitigating these hard-to-assess broader impacts of a shutdown is financially viable using the plant’s operating flexibility. Academic/practical relevance: Our social commerce perspective toward managing shutdown decisions deviates from the commonly used asset value maximization objective in merchant operations. Identifying operating policies that delay or decrease the likelihood of a shutdown without incurring a significant asset value loss supports socially responsible plant shutdown decisions. Methodology: We formulate a constrained Markov decision process to manage shutdown decisions and limit the probability of future plant closures. We provide theoretical support for approximating this intractable model using unconstrained stochastic dynamic programs with modified shutdown costs and explore two classes of operating policies. Our first policy leverages anticipated regret theory, and the second policy generalizes, using machine learning, production-margin heuristics used in practice. We compute the former and latter policies using a least squares Monte Carlo method and combining this method with binary classification, respectively. Results: Anticipated-regret policies possess desirable asymptotic properties absent in classification-based policies. On instances created using real data, anticipated-regret and classification-based policies outperform practice-based production-margin strategies. Significant reductions in shutdown probability and delays in plant closures are possible while incurring small asset value losses. Managerial implications: A plant’s operating flexibility provides an effective lever to balance the social objective to reduce closures and the financial goal to maximize asset value. Adhering to both objectives requires combining short-term commitments with external stakeholders to avoid shutdown with longer-term internal efforts to reduce the probability of plant closures.

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Concurrent scheduling and layout of virtual manufacturing cells considering assembly aspects

Proceedings of the Institution of Mechanical Engineers Part B Journal of Engineering Manufacture ◽

10.1177/0954405420980685 ◽

2020 ◽

pp. 095440542098068

Author(s):

Kamran Forghani ◽

S. M. T. Fatemi Ghomi ◽

Reza Kia

Keyword(s):

Mathematical Model ◽

Simulated Annealing ◽

Model Material ◽

Virtual Manufacturing ◽

Superior Performance ◽

Shop Floor ◽

Processing Route ◽

Manufacturing Cells ◽

Comparison Results ◽

Virtual Manufacturing Cells

Cell formation, scheduling, and facility layout are three main decisions in designing manufacturing cells. In this paper, we address the integration of these decisions in virtual manufacturing cells considering assembly aspects and process routing. We develop a mathematical model to determine the machine cells, the layout of machines and workstations on the shop floor, the processing route of parts, and the production sequence of operations on the machines. In this mathematical model, material handling costs and cycle time are minimized. To the best of our knowledge, this is the first paper that concurrently addresses the scheduling and layout of virtual manufacturing cells with assembly aspects and so-called criteria. To effectively solve the problem, a Population-based Simulated Annealing (PSA) combined with linear programming is proposed. The practical usability of the developed model is demonstrated in a case study. Finally, instances from the literature are solved to evaluate the performance of the PSA. The comparison results showed the superior performance of the PSA in comparison with CPLEX solver and standard simulated annealing.

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Deploying NSBA algorithm for bi-objective manufacturing cells considering percentage utilisation of machines

International Journal of Intelligent Systems Technologies and Applications ◽

10.1504/ijista.2020.108082 ◽

2020 ◽

Vol 19 (3) ◽

pp. 257

Author(s):

Tamal Ghosh ◽

Kristian Martinsen

Keyword(s):

Manufacturing Cells

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Design of control programs for efficient handling of errors in flexible manufacturing cells

IEEE International Conference on Robotics and Automation, 2004. Proceedings. ICRA '04. 2004 ◽

10.1109/robot.2004.1307400 ◽

2004 ◽

Cited By ~ 3

Author(s):

J. Richardsson ◽

K. Danielsson ◽

M. Fabian

Keyword(s):

Flexible Manufacturing ◽

Manufacturing Cells ◽

Control Programs ◽

Flexible Manufacturing Cells

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Manufacturing and Fractional Cell Formation Using a New Binary Digit Grouping Algorithm with a Pwavroid Solution Explorer Toolkit

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.933.97 ◽

2014 ◽

Vol 933 ◽

pp. 97-105

Author(s):

Hassan Mroue ◽

Thien My Dao

Keyword(s):

Group Technology ◽

Cell Formation ◽

Optimal Solution ◽

Binary Digit ◽

Final Solution ◽

Manufacturing Cells ◽

Additional Cell ◽

Exceptional Elements ◽

Grouping Algorithm ◽

Fractional Cell

A new algorithm is presented in order to search for the optimal solution of the manufacturing and fractional cell formation problem. In addition, this paper introduces a new toolkit, which is used to search for the various candidate solutions in a periodic and a waving (diversified) manner. The toolkit consists of 15 tools that play a major role in speeding up the obtainment of the final solution as well as in increasing its efficiency. The application of the binary digit grouping algorithm leads to the creation of manufacturing cells according to the concept of group technology. The nonzero entries, which remain outside the manufacturing cells, are called exceptional elements. When a lot of such elements is obtained, an additional cell called fractional (or remainder) cell may be formed; the aim of which is to reduce their number. This algorithm was tested by using illustrative examples taken from the literature and succeeded to give better or at least similar results when compared to those of other well-known algorithms.

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