Gonzalo Guillén

Simultaneous optimization of process operations and financial decisions to enhance the integrated planning/scheduling of chemical supply chains

Abstract This paper addresses the integrated planning/scheduling of chemical supply chains (SC) with multi-product, multi-echelon distribution networks taking into account financial management issues and suggests a novel approach for enterprise wide management. In order to tackle this problem, it is derived a mathematical formulation combining a scheduling/planning model with a cash flow and budgeting formulation. To motivate the use of such integrated model, a sequential scheme representing traditional enterprise practices is firstly applied. Within this strategy, scheduling and planning decisions are taken firstly, and finances are fitted afterwards considering the cash flows associated to the scheduling/planning decisions previously computed as input parameters. The comparison between the results of the sequential approach and those of the integrated model highlight the advantages of the latter option, in which scheduling/planning and cash management decisions are optimized in unison with a common objective of maximizing the change in equity achieved by the company. The modeling approach developed in this paper and the obtained results suggest that a new conceptual strategy in enterprise management systems consisting of the integration of the financial models of the enterprise with those dealing with the operative area is a must to improve the firm’s performance and its overall earnings and ensuring also healthy cash flow management.

An agent-based approach for supply chain retrofitting under uncertainty

In this work, decisions that have a long lasting effect on the supply chain (SC) such as the design and retrofit of a production/distribution network are considered. The retrofitting tasks are accomplished by using a SC agent-oriented simulation system, which model each entity belonging to the SC as an independent agent. The starting point is a set of possible design options for the existing SC. For each design alternative a performance index is obtained through the agent-based framework by looking for the best value of the operational variables associated to the resulting network. The proposed methodology allows to address the design of complex SCs which are hard to be modelled otherwise, for example by means of standard mathematical programming tools. Specifically, the multi-agent system is suitable for SCs that are either driven by pull strategies or operate under uncertain environments, in which the mathematical programming approaches are likely to be inferior due to the high computational effort required. The advantages of our approach are highlighted through a case study comprising several plants, warehouses and retailers.

Empowering financial tradeoff with joint financial and supply chain planning models

The concept behind improved enterprise systems is the overall integration of its whole functionality through optimised financial links. This paper addresses the implementation of financial cross functional links through the integration of production scheduling and planning with financial management in a modelling framework aimed at chemical process industries. Altogether models must play a more active role, recommending besides schedules and plans, the optimal budgetary decisions for each new scenario. The platform built combines a deterministic cash flow management model with a MILP formulation of process operation. The advantages of this approach are highlighted through case studies.

Integrating pricing policies and risk management into scheduling of batch plants

Abstract In this work a new strategy for integrating pricing decisions and market share information with the schedule of batch plants is introduced. Several parameters such as product demand and the relationship between prices and demand are considered uncertain and a two-stage stochastic programming model is used. Financial risk is managed.

Integrating short-term budgeting into multi-site scheduling

Abstract In this work a novel approach is applied with the aim to improve the operation of supply chains with embedded multi-purpose batch chemical plants. The major contribution of this work with respect to previous approaches is that it includes a corporate financial planning model within the mathematical formulation applied for optimizing scheduling/planning decisions variables regarding the supply chain management. Such model maximizes the change in equity of the company and provides the budgetary guidelines for the planned period. This consideration exhibits two main advantages compared to the existing methodologies. In first place, it allows to check the feasibility of the resulting planning decisions from the financial viewpoint thus ensuring that the production and distribution activities to be carried out through the different nodes of the network do not spend more cash than the available one. In second place, it leads to better overall economic performance than in previous methodologies since the model properly evaluates the impact of financial expenses and earnings derived from the SC operation thus integrating production and financial corporate decisions. Such integration also makes the difference when considering the opportunity of investing the idle cash.

Integrating production and transport scheduling for supply chain management under market uncertainty

Abstract In this work, a novel approach to increase Supply Chain (SC) competitiveness is introduced. The proposed strategy helps to co-ordinate the production/distribution tasks of the nodes embedded in a SC by integrating the plant production scheduling with the transport scheduling to final markets Uncertainty in the demands is considered and the problem is formulated as a two-stage stochastic optimisation approach. The mathematical model looks for the detailed global schedule (production and transport) that maximises the expected benefit. A motivating example is used to illustrate the above strategy