Optimal Operating Policy for a Random Additional Service Facility

1982 ◽  
Vol 33 (9) ◽  
pp. 837
Author(s):  
K. Bidhi Singh
Keyword(s):  
Optimal Operating ◽  
Service Facility ◽  
Operating Policy ◽  
Additional Service ◽  
Optimal Operating Policy

Modular Simulation to Determine the Optimal Operating Policy of a Batch Reactor for the Enzymatic Fructose Reduction to Mannitol with the in situ Continuous Enzymatic Regeneration of the NAD Cofactor

2017 ◽  
Vol 68 (9) ◽  
pp. 2196-2203 ◽  
Author(s):  
Mara Crisan ◽  
Gheorghe Maria
Keyword(s):  
Batch Reactor ◽  
Production Capacity ◽  
Optimization Procedure ◽  
Enzymatic Reactions ◽  
Mannitol Dehydrogenase ◽  
Optimal Operating ◽  
Operating Policy ◽  
Enzymatic Reduction ◽  
Optimal Operating Policy

Novel coupled enzymatic systems reported important applications in the industrial bio-catalysis. Multi-enzymatic reactions can successfully replace complex chemical syntheses, using milder reaction conditions, and generating less waste. For such systems acting simultaneously, the model-based engineering calculations (design, reactor operation optimization) are difficult tasks, because they must account for interacting reactions, differences in enzymes optimal activity domains and deactivation kinetics. The determination of the optimal operating mode (enzyme ratios, enzyme feeding policy, temperature, pH) often turns into a difficult multi-objective optimization problem with multiple constraints to be solved for every particular system. The paper focuses on applying a modular screening procedure that can identify the optimal operating policy of an enzymatic reactor, which minimizes the enzyme consumption, given the process kinetic model, and an imposed production capacity. Following an optimization procedure, the process effectiveness is evaluated in a systematic approach, by including simple batch reactor (BR), batch with intermittent addition of the key-enzyme following certain optimal policies (BRP). Exemplification is made for the case of the enzymatic reduction of D-fructose to mannitol by using suspended MDH (mannitol dehydrogenase) and NADH (Nicotinamide adenine dinucleotide) cofactor, with the in-situ continuous regeneration of the cofactor by the expense of formate degradation in the presence of suspended FDH (Formate dehydrogenase).

scholarly journals Incorporating Outsourcing Strategy and Quality Assurance into a Multiproduct Manufacturer–Retailer Coordination Replenishing Decision

Mathematics ◽  
2020 ◽  
Vol 8 (12) ◽  
pp. 2212
Author(s):  
Yuan-Shyi Peter Chiu ◽  
Victoria Chiu ◽  
Tsu-Ming Yeh ◽  
Hua-Yao Wu
Keyword(s):  
Quality Assurance ◽  
Cycle Time ◽  
Cost Effective ◽  
Managerial Decision ◽  
Optimal Operating ◽  
Supply Chain System ◽  
Operating Policy ◽  
Multiproduct Manufacturing ◽  
The Impact ◽  
Optimal Operating Policy

This study explores the multiproduct manufacturer-retailer coordination replenishing decision featuring outsourcing strategy and product quality assurance. Globalization has generated enormous opportunities. Consequently, transnational firms now face tough competition in global markets. To stay competitive, a firm should meet the client’s multi-item and quality requirements under capacity constraints and optimize the intra-supply chain system to allow the timely distribution of finished goods under minimum system cost. The outsourcing option is considered to release machine loadings and reduce cycle time effectively. All items fabricated are screened for quality, and reworkable and scrap items are separated. Any reworked items that fail the quality reassurance screening are discarded, whereas all outsourced products are quality-guaranteed by the provider. A fixed-quantity multi-shipment plan is used when the whole finished lot is quality-ensured to help present-day transnational firms gain competitive advantage by making efficient and cost-effective multiproduct manufacturing and delivering decisions. Mathematical modeling is built to portray the system’s characteristics, and conventional differential calculus is used to solve and derive the optimal operating policy for the proposed problem. Simultaneously, we find the optimal delivery frequency and common cycle time for the problem mentioned above. A simulated numerical example and sensitivity analysis demonstrate the research result’s capability and applicability. Our precise analytical model can reveal/highlight the impact of deviations in quality- and outsourcing-related features on the optimal operating policy and several performance indicators that help managerial decision-making.

Stochastic Model for Machining Processes—Optimal Decision-Making and Control

1971 ◽  
Vol 93 (2) ◽  
pp. 593-602 ◽  
Author(s):  
S. M. Wu ◽  
J. G. Dalal
Keyword(s):  
Stochastic Model ◽  
Cost Model ◽  
Planning Horizon ◽  
Optimal Decision ◽  
Machine Process ◽  
Machining Processes ◽  
Optimal Operating ◽  
Operating Policy ◽  
Screw Machine ◽  
Optimal Operating Policy

An automatic screw machine process is used as an example to investigate machining operations. Experiments were conducted and a stochastic model for the time series on observed performance of the machine was identified. With the stochastic model, it is possible to forecast the future performance. A simple cost model is assumed for the machining operation and an operating criterion of minimum expected cost per period of operation is used to determine the optimal operating policy. A rolling policy method was used to obtain the optimal operating policy for an indefinite planning horizon. The automatic screw machine process was simulated on a digital computer to determine its performance. The stochastic portion of the deviations from the target was corrected, and the extent of correction was shown to be determined by the cost parameters.

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