DSpace
 

Researchspace >
General science, engineering & technology >
General science, engineering & technology >
General science, engineering & technology >

Please use this identifier to cite or link to this item: http://hdl.handle.net/10204/5378

Title: Novel technique for prediction of time points for scheduling of multipurpose batch plants
Authors: Seid, R
Majozi, T
Keywords: Time points
State sequence network
Multipurpose batch plants
Chemical engineering science
Issue Date: Jan-2012
Publisher: Elsevier
Citation: Seid, R and Majozi, T. 2012. Novel technique for prediction of time points for scheduling of multipurpose batch plants. Chemical Engineering Science, Vol 68(1), pp 54-71
Series/Report no.: Workflow request;7603
Abstract: This paper presents a mathematical technique for prediction of the optimal number of time points in short-term scheduling of multipurpose batch plants. The mathematical formulation is based on state sequence network (SSN) representation. The developed method is based on the principle that the optimal number of time points depends on how frequent the critical unit is used throughout the time horizon. In the context of this work, a critical unit refers to a unit that is most frequently used and it is active for most of the time points when it is compared to other units. A linear model is used to predict how many times the critical unit is used. In conjunction with knowledge of recipe, this information is used to determine the optimal number of time points. The statistical R2 value obtained between the predicted and actual number of optimal time points in all the problems considered was 0.998, which suggests that the developed method is accurate in determining optimal number of time points. Consequently this avoids costly computational times due to iterations. In the model by Majozi and Zhu (2001) the sequence constraint that pertains to tasks that consume and produce the same state, the starting time of the consuming task at time point p must be later than the finishing time of the producing task at the previous time point p-1. This constraint is relaxed by the proposed models if the state is not used at the current time point p. This relaxation gives a better objective value as compared to previous models. An added feature of the proposed models is their ability to exactly handle fixed intermediate storage (FIS) operational philosophy, which has proven to be a subtle drawback in published scheduling techniques.
Description: Copyright: 2012 Elsevier. This is an ABSTRACT ONLY
URI: http://www.sciencedirect.com/science/article/pii/S0009250911006178
http://hdl.handle.net/10204/5378
ISSN: 0009-2509
Appears in Collections:Advanced mathematical modelling and simulation
General science, engineering & technology

Files in This Item:

File Description SizeFormat
Seid_2011_ABSTRACT ONLY 1.pdf14.66 kBAdobe PDFView/Open
View Statistics

Items in DSpace are protected by copyright, with all rights reserved, unless otherwise indicated.

 

Valid XHTML 1.0! DSpace Software Copyright © 2002-2010  Duraspace - Feedback