Design problem retrofit

Multi-product batch plant Two cases (a) minimization of both investment and number of different sizes for each unit operation, and (b) minimization of investment, number of different sizes for each unit operation and number of campaigns to reach steady state or oscillatory regime. Multi-Objective GA (MOGA) Both design and retrofit problems were smdied. Dedieu et al. (2003)... 

Since the retrofit problem can be viewed as a particular case of the design problem with specific constraints that capture the existing situation of the plant, the conceptual batch process retrofit problem proposed by Reklaitis (1989) can be decomposed into four decision levels. 

Whatever the case of batch plants, either of multiproduct or multipurpose nature, few works have addressed the retrofit problem compared with the batch plant design problem. Most of the mathematical formulations used to model the retrofit problem usually lead to optimization-oriented problems. It must be also emphasized that scheduling is intrinsically associated with batch plant design/retrofit, and is part and parcel of the formulation of both issues. It can be considered as a sub-problem of the design/retrofit problem. As highlighted in the compared formulation of these companion problems, the retrofit problem appears to be a more constrained problem. Yet, the basic solution strategy involves the same mathematical approaches and tools. 

The discrete decisions involved in both design and retrofit situations (for example, equipment number and allocation, task allocation) lead to an inherent combinatorial aspect, which is challenging from the computational complexity point of view (Pekny and Reklaitis, 1998). These problems are identified as NP-hard (Non-deterministic Polynomial-time hard) problems (Garey and Johnson, 1979), so that there is no known algorithm that can solve the problem in a polynomial time. This feature makes stochastic methods particularly attractive to tackle such problems. 

The review paper by Barbosa-Pdvoa (2007) covered various approaches for both design and retrofit design problems. It is noteworthy that the approaches reported to the date of this publication took into account only retrofitting analysis regarding the scheduling of batch operations, and Barbosa-Pdvoa (2007) did not consider the benefits that can be achieved in terms of sustainable design. 

Part II presents mathematical models to approach the problem of integrating enterprise functionalities. Chapter2 addresses the design and retrofit of SCs taking into account financial concerns. The proposed framework applies MILP modeling... 

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