چارچوب جامع برای مدیریت زنجیره تامین کوتاه مدت به منظور یکپارچه سازی تولید و برنامه ریزی مالی شرکت

Traditional approaches for SCM usually focus on process operations and neglect the financial side of the problem. In this work we present a novel approach for holistically optimizing the combined effects of operations and finances in SCM. To achieve such integration between different business areas, it is derived an integrated model for SCM, which incorporates process operations as well as budgetary constraints. The novelty of this formulation lies not only in the insertion of financial aspects within a SC planning formulation, but also in the choice of a financial performance indicator, i.e. the change in equity, as the objective to be optimized in the integrated model. The main advantages of this mathematical formulation are highlighted through a case study, in which the results obtained by the integrated model are compared with those computed by the traditional sequential strategy, in which the operations are firstly computed and the finances are fitted afterwards. The obtained results show the importance of devising broader modeling systems for SCM leading to increased overall earnings and providing further insights on the interactions between operations and finances.

The concept of supply chain management (SCM), which appeared in the early 1990s, has recently raised a lot of interest since the opportunity of an integrated management of the supply chain (SC) can reduce the propagation of unexpected/undesirable events through the network and can influence decisively the profitability of all the members. SCM looks for the integration of a plant with its suppliers and its customers to be managed as a whole, and the co-ordination of all the input/output flows (materials, information and finances) so that products are produced and distributed at the right quantities, to the right locations, and at the right time (Simchi-Levi et al., 2000). A large body of literature exists on SC analysis and optimization (Bok et al., 2000, Tsiakis et al., 2001 and Cheng et al., 2003; Guillén et al., 2005a, Guillén et al., 2005b, Guillén et al., 2005c and Guillén et al., 2006). Traditional SC models focus solely on determining the profit or revenue-maximizing, or cost-minimizing production schedule in a SC that runs from suppliers to manufacturing plants to distribution facilities and finally to retail outlets. These models neglect the cash-flow consequences of the optimal production schedule, such us opportunity costs associated with missed investment opportunities, interest on debt, etc. Until today, process operations and finances have been treated as separate problems and the modeling approaches supporting them have been traditionally implemented in independent environments. Although the need to account for financial aspects when constructing process operations models has been pointed out in the literature (Applequist et al., 2000, Shapiro, 2001 and Shah, 2005), the integration of both areas has so far received little attention and is currently waiting for further study. However, the works of Romero et al. (2003) and Badell et al. (2004), which address the integration of financial aspects with short-term planning in the batch chemical process industry (CPI) are appreciated contributions to the field. At the design level, Yi and Reklaitis (2004) have also presented an integrated analysis of production and financing decisions regarding the optimal design of batch-storage networks. An integrated tool for SCM would allow managers to “play” with different planning alternatives taking into account all the available information and having a clear idea of the consequences of each alternative being tested. With this aid, it is possible to properly assess the impact of the process operations decisions on the financial area and to shift the slave/blind position of the business level towards a more prevalent role in SCM. This new philosophy will make managers gain a competitive advantage compared with those that check neither the feasibility nor the optimality of the process operations decisions from the financial viewpoint. The purpose of the present paper is to introduce budgetary considerations into a basic SC model and direct the management's attention in the production-planning process to the more general objective of maximizing the firm's net equity. The paper is organized as follows. First, a standard deterministic SC scheduling–planning model is presented. Then, budgeting models are reviewed, and a budgeting model suitable for SCM is described. Next, the integrated deterministic model, which merges SC operations and finances, is presented. Finally, a motivating example is introduced and the results computed by means of the integrated model are compared with those determined by the traditional sequential approach, in which the SC planning model is firstly computed and the finances are fitted afterwards.

This paper has addressed the importance of integrating planning and budgeting models in SCM. To achieve the integration, a standard SC planning formulation has been extended through the insertion of budgeting constraints that explore the financial area of the SC. The change in equity, which is related to the shareholders’ value (SHV) of the firm, has been chosen as the objective to be optimized in the integrated SC planning/budgeting model. The advantages of our approach have been highlighted through a case study, in which the results obtained by the integrated model have been compared with those determined by the sequential strategy, in which operations are firstly decided and finances are fitted afterwards. Results indicate that the sequential approach leads to poorer solutions, in terms of change in equity, than the integrated formulation. This illustrates the inadequacy of treating process operations and finances in isolated environments and pursuing as objective myopic performance indicators such as profit or cost. The implications for production scheduling, for the firm's cash flow, and for stockholder equity that incorporating financial considerations into a SC analysis can have, may well differ from firm to firm, depending upon the specifics of the situation. We believe that the PSE community must enlarge the scope of the currently narrow approaches for SCM and extend the underlying concepts and ideas to offer a wider perspective of the whole business at all the decision-support levels (operational, tactical and strategic). It is a fact that the tight profit margins under which the chemical industry will operate in the future will make managers pay more and more attention to the financial area. Thus, the approach of this work will become more relevant in the course of time, not only in the academic world but also in the industrial community.