Imperial College London
Alternate

Professor Nilay Shah OBE FREng

Faculty of Engineering, Department of Chemical Engineering

Professor of Process Systems Engineering
 
 
 
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Contact

 

+44 (0)20 7594 6621n.shah

 
 
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Assistant

 

Miss Jessica Baldock +44 (0)20 7594 5699

 
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Location

 

ACEX 522ACE ExtensionSouth Kensington Campus

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Summary

 

Publications

Publication Type
Year
to

677 results found

Margono E, Samsatli N, Shah N, 2007, Generic Modelling and Simulation of Stock Levels in Supply Chains, 17th European Symposium on Computer Aided Process Engineering (ESCAPE-17), Publisher: ELSEVIER SCIENCE BV, Pages: 775-780, ISSN: 1570-7946

Conference paper

Rodriguez-Fernandez M, Kucherenko S, Pantelides C, Shah Net al., 2007, Optimal experimental design based on global sensitivity analysis, 17th European Symposium on Computer Aided Process Engineering (ESCAPE-17), Publisher: ELSEVIER SCIENCE BV, Pages: 63-68, ISSN: 1570-7946

Conference paper

Stefansson H, Jensson P, Shah N, 2006, An efficient procedure to increase robustness of production plans embedded in an integrated multi-scale planning and scheduling approach, AIChE Annual Meeting, Conference Proceedings

In these presentation records we propose a procedure to increase robustness of production plans embedded in a modelling approach based on integrated multi-scale optimization models and solution methods for planning and scheduling of a make to order production process under uncertain and varying demand conditions. As an inspiration we have a large real world problem originating from a complex pharmaceutical enterprise. The approach is based on a hierarchically structured moving horizon algorithm. On each level in the algorithm we propose optimization models to provide support for the relevant decisions and the models are solved with decomposition heuristics. The levels are diverse regarding the time scope, aggregation, update rate and availability of data at the time applied. The maximum effective time horizon of the multi-scale approach is one year and we use sales forecasts as input demands instead of actual orders which are usually only available 3 months ahead in time although raw materials need to be procured up to one year in advance. The sale forecasts have historically proven to be rather uncertain and to increase the robustness of our long-term plans we use an iterative procedure where the first step is to use a MILP model to obtain a solution based on the sale forecasts. In the next step we generate a number of alternative demand scenarios and run LP models to test the robustness of the MILP solution for each of the demand scenarios. If the long-term production plan is feasible for enough of the demand scenarios, depending on our robustness criteria, then we use the current plan, but if not then we change the demand forecast and run the MILP model again iteratively until the robustness criterion has been met. The demand samples are generated with tailor-made methods based on statistical error analysis. The approach has been tested and implemented with industrial data from a pharmaceutical enterprise and has proved to be capable of obtaining realistic and pr

Journal article

Stefansson H, Shah N, Jensson P, 2006, Multiscale planning and scheduling in the secondary pharmaceutical industry, AICHE JOURNAL, Vol: 52, Pages: 4133-4149, ISSN: 0001-1541

Journal article

Almansoori A, Shah N, 2006, Design and operation of a future hydrogen supply chain - Snapshot model, CHEMICAL ENGINEERING RESEARCH & DESIGN, Vol: 84, Pages: 423-438, ISSN: 0263-8762

Journal article

Tsang KH, Samsatli NJ, Shah N, 2006, Modelling and planning optimization of a complex flu vaccine facility, FOOD AND BIOPRODUCTS PROCESSING, Vol: 84, Pages: 123-134, ISSN: 0960-3085

Journal article

Hung WY, Samsatli NJ, Shah N, 2006, Object-oriented dynamic supply-chain modelling incorporated with production scheduling, 6th International Conference on Industrial Engineering and Production Management, Publisher: ELSEVIER, Pages: 1064-1076, ISSN: 0377-2217

Conference paper

Stefansson H, Jensson P, Shah N, 2006, Integration of multi-scale planning and scheduling problems, Joint Conference Event of the 9th Symposium on Process Systems Engineering (PSE 2006)/16th European Symposium on Computer Aided Process Engineering (ESCAPE-16), Publisher: ELSEVIER SCIENCE BV, Pages: 2111-2116, ISSN: 1570-7946

Conference paper

See-Toh YC, Walsh SPK, Shah N, 2006, Multi-Period Capacitated Lot Sizing with Variable Batch Sizes, Joint Conference Event of the 9th Symposium on Process Systems Engineering (PSE 2006)/16th European Symposium on Computer Aided Process Engineering (ESCAPE-16), Publisher: ELSEVIER SCIENCE BV, Pages: 1949-1954, ISSN: 1570-7946

Conference paper

Shah N, Samsatli NJ, Ashe R, Barker R, Morris Det al., 2005, A modelling and experimental study of constant flux heat transfer for improved process development and process operation, 7th World Congress of Chemical Engineering, GLASGOW2005, incorporating the 5th European Congress of Chemical Engineering

Despite countless improvements in heat exchanger design, the fundamental approach to controlling heat transfer has remained unchanged for over 100 yr. A very recent development in the field is the concept of constant flux heat transfer technology. Apart from offering better temperature control, the constant flux method allows the user to measure heat changes in the process with great accuracy. This gives rise to three significant benefits in process development and operation, i.e., improved calorimetry at the small scale for rapid elucidation of reaction kinetics; improved temperature control during operation; and improved end-point detection in batch processes. Model- and experiment-based studies, which quantify the benefits of constant flux in these three areas are presented using common chemical reaction schemes to support the analysis. This is an abstract of a paper presented at the 7th World Congress of Chemical Engineering (Glasgow, Scotland 7/10-14/2005).

Journal article

Moggridge G, Shah N, 2005, Special issue - 7th World Congress of Chemical Engineering, CHEMICAL ENGINEERING RESEARCH & DESIGN, Vol: 83, Pages: 559-560, ISSN: 0263-8762

Journal article

Roe B, Papageorgiou LG, Shah N, 2005, A hybrid MILP/CLP algorithm for multipurpose batch process scheduling, 14th European Symposium on Computer Aided Process Engineering (ESCAPE-14), Publisher: PERGAMON-ELSEVIER SCIENCE LTD, Pages: 1277-1291, ISSN: 0098-1354

Conference paper

Shah N, 2005, Process industry supply chains: Advances and challenges, 14th European Symposium on Computer Aided Process Engineering (ESCAPE-14), Publisher: PERGAMON-ELSEVIER SCIENCE LTD, Pages: 1225-1235, ISSN: 0098-1354

Conference paper

Jaimoukha IM, El-Zobaidi H, Limebeer DJN, Shah Net al., 2005, Controller reduction for linear parameter-varying systems with a priori bounds, AUTOMATICA, Vol: 41, Pages: 273-279, ISSN: 0005-1098

Journal article

Gjerdrum J, Samsatli NJ, Shah N, Papageorgiou LGet al., 2005, Optimisation of policy parameters in supply chain applications, International Journal of Logistics Research and Applications, Vol: 8, Pages: 15-36, ISSN: 1367-5567

In this paper, three approaches for finding optimal parameters for supply chain systems are described and evaluated. The first approach is based on rigorous mixed integer linear programming concepts. Although using this approach guarantees finding the optimal solution for the policy parameters, the drawback of applying such a model to supply chain networks is the excessive computational requirements. The second approach is to combine a detailed stochastic simulation model with a simulated annealing algorithm. While optimality is no longer guaranteed with this approach, far larger problems should be tractable. Finally, a gradient-based approach is suggested, in which a higher-level optimiser utilises the results from the same detailed stochastic simulation model to obtain the optimal parameters. Results obtained when introducing small deviations to the policy parameters are used to estimate the gradients, which are used by the higher-level model. Two case studies are considered: a simple reorder-point warehouse example and an industrial-scale multi-site production distribution problem. The first example is used to compare the effectiveness of the simulated annealing and gradient-based approaches with the rigorous mixed integer linear programming (MILP) formulation. In the industrial example, only simulated annealing and simple gradient-based methods are applied, as the MILP model becomes intractable. Here, dynamic safety stock levels and order quantities are primarily investigated.

Journal article

Shah N, McDonald CM, 2005, Supply-chain management, Batch Processes, Pages: 463-514, ISBN: 9780824725228

A supply chain encompasses a firm’s or several firms’ facilities and resources and the relationships between the facilities and resources required to plan, manage, and execute: • The sourcing of materials • The making of intermediate and final products • The delivery of end products to customers.

Book chapter

Stefansson H, Shah N, 2005, Multi-scale planning and scheduling in the pharmaceutical industry, 15th European Symposium on Computer Aided Process Engineering (ESCAPE-15), Publisher: ELSEVIER SCIENCE BV, Pages: 1003-1008, ISSN: 1570-7946

Conference paper

Sousa RT, Shah N, Papageorgiou LG, 2005, Global supply chain network optimisation for pharmaceuticals, Amsterdam, European Symposium on Computer-Aided Process Engineering-15, Publisher: Elsevier Science Bv, Pages: 1189-1194

Conference paper

Hung WY, Kucherenko S, Samsatli NJ, Shah Net al., 2004, A flexible and generic approach to dynamic modelling of supply chains, JOURNAL OF THE OPERATIONAL RESEARCH SOCIETY, Vol: 55, Pages: 801-813, ISSN: 0160-5682

Journal article

Shah N, 2004, Pharmaceutical supply chains: key issues and strategies for optimisation, International Conference on Foundations of Computer-Aided Process Operations, Publisher: PERGAMON-ELSEVIER SCIENCE LTD, Pages: 929-941, ISSN: 0098-1354

Conference paper

Roe B, Pagageorgiou LG, Shah N, 2004, A hybrid formulation for multipurpose batch process scheduling, 14th European Symposium on Computer Aided Process Engineering (ESCAPE-14), Publisher: ELSEVIER SCIENCE BV, Pages: 985-990, ISSN: 1570-7946

Conference paper

Shah N, 2004, Process industry supply chains: Advances and challenges, 14th European Symposium on Computer Aided Process Engineering (ESCAPE-14), Publisher: ELSEVIER SCIENCE BV, Pages: 123-138, ISSN: 1570-7946

Conference paper

Gatica G, Papageorgiou LG, Shah N, 2003, Capacity planning under uncertainty for the pharmaceutical industry, CHEMICAL ENGINEERING RESEARCH & DESIGN, Vol: 81, Pages: 665-678, ISSN: 0263-8762

Journal article

Shah N, 2003, Special topic issue - Process design, CHEMICAL ENGINEERING RESEARCH & DESIGN, Vol: 81, Pages: 505-505, ISSN: 0263-8762

Journal article

Hung WY, Kucherenko S, Samsatli NJ, Shah Net al., 2003, An efficient sampling technique for stochastic supply chain simulations

To enable a fair comparison of various supply chain initiatives, realistic supply chain simulation models need to capture the system dynamics and characteristics of individual supply chain members by modelling their physical and business activities. Of equal importance is the need to quantit' the supply chain performance under uncertainty. This requires detailed stochastic models that are usually very high in dimension and thus require extensive computation. In this paper we present an efficient sampling technique to reduce the number of simulations required to obtain accurate performance metrics. Latin Supercube Sampling (LSS) based on Sobol' subsets is applied to generate the sample points for the uncertain variables. Numerical experiments and a case study are used to illustrate the higher efficiency of this sampling method.

Other

Roe B, Shah N, Papageorgiou LG, 2003, A hybrid CLP and MILP approach to batch process scheduling, 8th International Symposium on Process Systems Engineering, Publisher: ELSEVIER SCIENCE BV, Pages: 582-587, ISSN: 1570-7946

Conference paper

Gjerdrum J, Shah N, Papageorgiou LG, 2002, Fair transfer price and inventory holding policies in two-enterprise supply chains, EUROPEAN JOURNAL OF OPERATIONAL RESEARCH, Vol: 143, Pages: 582-599, ISSN: 0377-2217

Journal article

Hamel JFP, Shah N, 2002, Model validation of soluble protein production., ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY, Vol: 224, Pages: U214-U214, ISSN: 0065-7727

Journal article

Huang HT, Adjiman CS, Shah N, 2002, Quantitative framework for reliable safety analysis, AICHE JOURNAL, Vol: 48, Pages: 78-96, ISSN: 0001-1541

Journal article

Feord D, Jakeman C, Shah N, 2002, Modelling multi-site production to optimise customer orders, 12th European Symposium on Computer Aided Process Engineering (ESCAPE-12), Publisher: ELSEVIER SCIENCE BV, Pages: 661-666, ISSN: 1570-7946

Conference paper

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