Concepts,Theory, and Techniques DISTRIBUTED COMPUTER SYSTEM DESIGN: A MULTICRITERIA DECISION-MAKING METHODOLOGY*

The design of distributed computer systems (DCSs) requires compromise among several conflicting objectives. For instance, high system availability conflicts with low cost which in turn conflicts with quick response time. This paper presents an approach, based on multi-criteria decision-making techniques, to arrive at a good design in this multiobjective environment. An interactive procedure is developed to support the decision making of system designers. Starting from an initial solution, the procedure presents a sequence of non-dominated vectors to designers, allowing them to explore systematically alternative possibilities on the path to a final design. The model user has control over trade-offs among different design objectives. This paper focuses on the details of the mathematical model used to provide decision support. Accordingly, a formulation of DCS design as a multicriteria decision problem is developed. The exchange search heuristic used to generate nondominated solutions also is presented. We argue that multicriteria models provide a more realistic formulation of the DCS design problem than the single-criterion models used widely in the literature. While obtaining a clear definition of design objectives (single or multiple) is an important activity, by explicitly acknowledging the trade-offs among multiple objectives in the design process, our methodology is more likely to produce a better overall design than methods addressing a single criterion in isolation.     

The Present Value Issue in a Sequential Selection Problem*

This note shows that, due to the misapplication of the present value concept, the Chun and Platt (CP) formulation of a sequential selection problem, which intends to improve on the Kwan and Yuan (KY) analysis, is flawed and the decision criterion thus obtained is invalid. In the context of capital budgeting, we make necessary corrections to the CP analysis and establish a decision criterion which is more refined than the KY case. The refined decision criterion enables us to evaluate the KY analysis objectively and to refute CP's argument about its suboptimality. We also address the managerial implications of the refined decision criterion.     

Formulating the mess: The role of decision aids in problem formulation

Analytic decision aids have been criticized by some practitioners for their inability to address questions of problem formulation. These aids typically begin with the assumption that a problem has been recognized and stated, and that the task of the sequential step-wise analysis process is to indicate the optimal strategy in terms of a specified choice criterion. Writers such as Ackoff, Mason & Mitroff and Raiffa have argued that this approach may lead to solving the wrong problem, particularly when applied to ill-structured, complex organizational decision problems. The purpose of this paper is to provide a more thorough understanding of the nature of problem formulation and the use of techniques for assisting decision-makers in this process. The paper attempts first to develop an understanding of the process of organizational problem formulation through the examination of current literature and research. This is seen to be a necessary prerequisite for discussing the value of decision aids for problem formulation. Second, attention is focused on aids to problem formulation. Included is discussion about the matching of problem to problem type, creativity stimulants, dialectical inquiry and devil's advocate approaches, as well as the role of formal analysis as a stimulant for a policy dialogue process. Finally, the relationships between the various approaches are examined and a synthetic model for their use in problem formulation is suggested.     

On the effectiveness of cognitive feedback from an interface agent

The objective of this study was to determine the impact of task information (TI) provided by an interface agent during the idea evaluation and integration step of the problem formulation stage of the problem solving process. The effectiveness assessment was based on solving diagnostic decision problems in the domain of complex industrial machinery. Ten domain experts participated in this study. Decision support was provided by a case-based reasoning system. Findings suggest that TI provided by the interface agent had no effect on the decision maker's performance, nor on the associated cognitive effort. However, a verbal protocol analysis revealed that the ten subjects used the interface agent to verify their decision processes. The results and their implications are discussed with respect to current findings in the area of decision support systems.     

基于OWG算子的不同形式偏好信息 的群决策方法

具有不同形式偏好信息的群决策是决策分析及群决策支持系统研究的一个新课题,它对 于进一步提高群决策支持系统的实用性和灵活性方面具有重要意义. 针对这类群决策分析,提 出了一种具有效用值、序关系值、模糊互补判断矩阵、互反判断矩阵等4 种形式偏好信息的群 决策方法. 在该方法中,首先给出了将不同形式的偏好信息均转化为互反判断矩阵形式的计算 公式;然后基于OWG算子将各决策者的偏好信息集结为群的偏好并进行方案的优选;最后给 出了一个算例.     

EDUCATION

The power of an integer programming approach—and more particularly a 0,1 programming approach—to resource allocation problems is not widely appreciated. Recent developments in mathematical programming and in problem formulation enable decision makers to deal explicitly with the special conditions which characterize real world problems in capital budgeting, scheduling, and facilities planning. In this paper, somewhat tutorial in nature, we seek to demonstrate formulation and solution of an equipment selection resource allocation problem with several special conditions. The problem can be solved on any reasonably equipped computer system. Sensitivity studies are also performed and discussed.     

Improving spare parts inventory control at a repair shop

We study spare parts inventory control for an aircraft component repair shop. Inspection of a defective component reveals which spare parts are needed to repair it, and in what quantity. Spare part shortages delay repairs, while aircraft operators demand short component repair times. Current spare parts inventory optimization methods cannot guarantee the performance on the component level, which is desired by the operators. To address this shortfall, our model incorporates operator requirements as time-window fill rate requirements for the repair turnaround times for each component type. In alignment with typical repair shop policies, spare parts are allocated on a first come first served basis to repairs, and their inventory is controlled using (s, S) policies. Our solution approach applies column generation in an integer programming formulation. A novel method is developed to solve the related pricing problem. Paired with efficient rounding procedures, the approach solves real-life instances of the problem, consisting of thousands of spare parts and components, in minutes.A case study at a repair shop reveals how data may be obtained in order to implement the approach as an automated method for decision support. We show that the implementation ensures that inventory decisions are aligned with performance targets.     

Analysis of justification problems in CIMS review and projection

Attempts to study justification problems related to advanced manufacturing systems such as CIMS are made. Such systems conceptually promise industries many significant advantages, but many justification procedures that are used in appraising such system proposals remain ill-suited because of their failure to incorporate multifaceted strategic and tactical issues. The aim in this paper is to review some of these procedures and finally propose a total systems approach. The objective is to make a prognosis of the issues to prepare a projective base for organizational decision support. Two case studies from Indian industries where CIMS have been tried out are also described.     

Trust in Islamic Business-to-Business Relationships: Evidence from Indonesia

We examine the role of trust within Islamic culture in business-to-business relationships by exploring the link between credit officers’ trust in business customers and their financing decisions. In line with our framework, which is based on the fact that Islamic culture is characterized by a collectivistic approach and clan-based social structure, we find that value-based trust is more important than competence-based trust in explaining business relationships. The results support the argument that Islamic culture business relationships are grounded more on the principles, values and norms that a partner brings to the relationship than on business skills. Our results are robust to endogeneity and multilevel issues.     

A decision support approach for two-stage multi-objective index tracking using improved lagrangian decomposition

We present a decision support approach for a network structured stochastic multi-objective index tracking problem in this paper. Due to the non-convexity of this problem, the developed network is modeled as a Stochastic Mixed Integer Linear Program (SMILP). We also propose an optimization-based approach to scenario generation to protect against the risk of parameter estimation for the SMILP. Progressive Hedging (PH), an improved Lagrangian scheme, is designed to decompose the general model into scenario-based sub-problems. Furthermore, we innovatively combine tabu search and the sub-gradient method into PH to enhance the tracking capabilities of the model. We show the robustness of the algorithm through effectively solving a large number of numerical instances.     

The Precautionary Principle and/or Risk Assessment in World Trade Organization Decisions: A Possible Role for Risk Perception

Risk analysis has been recognized and validated in World Trade Organization (WTO) decision processes. In recent years the precautionary principle has been proposed as an additional or alternative approach to standard risk assessment. The precautionary principle has also been advocated by some who see it as part of postmodern democracy in which more power is given to the public on health and safety matters relative to the judgments of technocrats. A more cynical view is that the precautionary principle is particularly championed by the European Community as a means to erect trade barriers. The WTO ruling against the European Community's trade barrier against beef from hormone-treated cattle seemed to support the use of risk assessment and appeared to reject the argument that the precautionary principle was a legitimate basis for trade barriers. However, a more recent WTO decision on asbestos contains language suggesting that the precautionary principle, in the form of taking into account public perception, may be acceptable as a basis for a trade barrier. This decision, if followed in future WTO trade disputes, such as for genetically modified foods, raises many issues central to the field of risk analysis. It is too early to tell whether the precautionary principle will become accepted in WTO decisions, either as a supplement or a substitute for standard risk assessment. But it would undermine the value of the precautionary principle if this principle were misused to justify unwarranted trade barriers.     

Coping with Group Behaviors in Uncertain Quality Function Deployment

Quality function deployment (QFD) is a planning and problem‐solving tool gaining wide acceptance for translating customer needs (CNs) into technical attributes (TAs) of a product. It is a crucial step to derive the prioritization of TAs from CNs in QFD. However, it is not so straightforward to prioritize TAs due to two types of uncertainties: human subjective perception and user variability. The main focus of this article is to propose a group decision‐making approach to uncertain QFD with an application to a flexible manufacturing system design. The proposed approach performs computations solely based on the order‐based semantics of linguistic labels to eliminate the burden of quantifying qualitative concepts in QFD. Moreover, it incorporates the importance weights of users and the concept of fuzzy majority into aggregations of individual fuzzy preference relations of different TAs in order to model the group behaviors in QFD. Finally, based on a quantifier‐guided net flow score procedure, the proposed approach derives a priority ranking with a classification of TAs into important and unimportant ones so as to provide a better decision‐support to the decision‐maker. Due to the easiness in articulating preferential information, our approach can reduce the cognitive burden of QFD planning team and give a practical convenience in the process of QFD planning.     

Retail category management: State-of-the-art review of quantitative research and software applications in assortment and shelf space management

Retail requires efficient decision support to manage increasing product proliferation and various consumer choice effects with limited shelf space. Our goal is to identify, describe and compare decision support systems for category planning. This research analyzes quantitative models and software applications in assortment and shelf space management and contributes to a more integrated modeling approach. There are difficulties commonly involved in the use of commercial software and the implementation and transfer of scientific models. Scientific decision models either focus on space-dependent demand or substitution effects, whereas software applications use simplistic rules of thumb. We show that retail assortment planning models neglect space-elastic demand and largely also ignore constraints of limited shelf space. Shelf space management streams on the other hand, mostly omit substitution effects between products when products are delisted orout-of-stock, which is the focus of consumer choice models in assortment planning. Also, the problem sizes of the models are often not relevant for realistic category sizes. Addressing these issues, this paper provides a state-of-the-art overview and research framework for integrated assortment and shelf space planning.     

Choosing a diversification project in a regulated economy

Choosing a diversification project in a regulated economy involves consideration of a large number of micro and macro issues. In order to make an optimal choice of strategy, a formal approach to diversification planning is necessary. This article develops an approach which aims at breaking up the problem of identification and selection of projects into manageable components. The approach involves three steps: identification of broad industry groups: identification of specific projects within each broad industry group; and comprehensive feasibility study. The major benefit of this approach lies in providing a systematic mechanism for reducing the number of alternatives and in recognizing the link between the internal management processes of strategy formulation with the political and administrative processes in government and regulatory bodies. The article is based largely on the Indian experience.     

A system for decision support without explicit objective functions

This paper presents a conversational decision support system: Resource Allocation in Business Operation under Uncertain Worth (RAINBOW). The focus is placed on the loosely structured decision situation where the multiple objective functions are given only implicitly and should be locally approximated by the decision maker as the decision making process proceeds. Basically, RAINBOW supports the process of convergence to a preferred alternative by giving the decision maker information which will help him form consistent evaluations of the utility function, the objective functions and the solution for the decision problem.     

Robust optimization in distribution-based demand planning: a model for negotiation support

In this paper a model for negotiation support in tactical procurement planning is designed, which is based on a real planning problem from the liquid gas trade sector. The problem is modeled as an assignment problem and transformed into a robust form. Computational experiments using data from a practice partner are presented to demonstrate the effective decision support of our approach.     

考虑不确定履约率的全局鲁棒供应组合决策研究

生产和采购的全球化为供应链企业带来了更多的复杂性与不确定性。收集全面信息和使用有效的工具是控制决策风险、减少不确定性危害的有效途径。在供应商选择与订单分配管理中,供应商履约率是影响企业供应组合决策的主要因素,如何对其进行定量刻画是迫切需要解决的问题。已有的研究通常是由期望方法或鲁棒方法来刻画履约率。然而,期望履约率法往往忽略了履约率的波动性,从而造成需求损失;而鲁棒履约率法通常存在过于保守、退化过于迅速两个缺点,使企业承担不必要的成本。本文研究供应商选择与订单分配决策问题,使用全局鲁棒优化的两个不确定集合来刻画供应商履约率,同时给出了这一问题的确定性鲁棒表达和一种多项式时间求解算法。最后,通过仿真实验证实本文的全局鲁棒优化模型可克服期望模型和一般鲁棒模型的缺点。本文提出的算法能有效求解本文全局鲁棒优化等价确定性问题,为企业的供应商选择和订单分配决策提供更为灵活精确的辅助工具。     

基于信任关系和信息测度的概率语义社会网络群决策模型

设计专家权重和属性指标权重的计算模型已成为近年来备受关注的两个重要研究课题。针对评价信息为概率语义信任函数的社会网络群决策问题,提出一种基于信任关系和信息测度的概率语义社会网络群决策模型。首先,构建基于信任关系的概率语义决策空间,探究专家之间的信任传递模型,通过专家之间信任关系计算专家的权重;其次,引入概率语义信任函数的熵和相似度概念,并运用三角函数设计概率语义信任函数信息熵和相似度的衡量方法;最后,构建基于信任关系和信息测度的概率语义社会网络群决策模型,进而得到合理可靠的决策结果,同时将提出的社会网络群决策模型用于电动汽车供应商的选择实例,对比分析实验验证了模型的合理性和有效性。