James R. Evans

Successful implementation of Six Sigma: benchmarking General Electric Company

The Six Sigma phenomenon has followed the TQM movement as the latest thrust for many companies seeking to improve their performance and effectiveness. The purpose of this paper is to review the basic concepts of Six Sigma, its benefits, and successful approaches for implementation. In particular, we benchmark the practices of the General Electric Company, one of the leaders and innovators in implementing the process. We conclude that keys for successful implementation include upper management support and involvement, organizational infrastructure, training, tools, and links to human resources‐based actions.

Aggregation and Disaggregation Techniques and Methodology in Optimization

A fundamental issue in the use of optimization models is the tradeoff between the level of detail and the ease of using and solving the model. Aggregation and disaggregation techniques have proven to be valuable tools for manipulating data and determining the appropriate policies to employ for this tradeoff. Furthermore, aggregation and disaggregation techniques offer promise for solving large-scale optimization models, supply a set of promising methodologies for studying the underlying structure of both univariate and multivariate data sets, and provide a set of tools for manipulating data for different levels of decision makers. In this paper, we develop a general framework for aggregation and disaggregation methodology, survey previous work regarding aggregation and disaggregation techniques for optimization problems, illuminate the appropriate role of aggregation and disaggregation methodology for optimization applications, and propose future research directions.

Heuristic “Optimization”: Why, When, and How to Use It

The pressing need of real-world problems for quick, simple, and implementable solutions coupled with a recently increased research productivity on improved and rigorously evaluated heuristic methods are rapidly increasing the need, usage, and respect for heuristics. This paper presents a framework for heuristic “optimization” by systematically examining this change in attitudes towards heuristics, their desirable features and proper usage.

Validating Key Results Linkages in the Baldrige Performance Excellence Model

The Malcolm Baldrige National Quality Award Criteria for Performance Excellence represent a framework for high-performance management systems. Although the criteria have evolved based on the collective wisdom of quality experts and management practitioners throughout the United States, little empirical research has been performed to validate the criteria and its core concepts and values. One of the key linkages in the criteria is the relationship between external results and internal performance metrics, which reflect the processes and management systems that drive results in an organization. The authors use a large empirical data set to explore these linkages, and apply canonical correlation to uncover significant relationships between variables, such as between employee satisfaction and process performance, and between work system improvement and productivity. These results: 1) validate some of the key linkages; 2) support long-standing beliefs and anecdotal evidence by practitioners of the relationships among endogenous and exogenous results for business performance; and 3) lend credibility to causal hypotheses that improving internal management practices leads to improvements in external results. As such, they provide new evidence of the validity of the Baldrige model and its examination/self-assessment process that seeks to validate strong business results as an outcome of high-performance management practices.

Heuristic methods and applications: A categorized survey

An extensive search of journal publications on heuristic methods and applications produced 442 articles published in 37 journals during the last sixteen years. A scheme is employed to categorize each article according to 12 classes of heuristic approaches and 144 areas of applications (the latter taken from the OR/MS subject classification codes). An analysis of these data reveals some interesting historical patterns and directions for future work. This categorized survey should be helpful to students, teachers, researchers and practitioners interested in heuristics.

An efficient implementation of the Wagner-Whitin algorithm for dynamic lot-sizing

Abstract We consider an N-period planning horizon with known demands D t ordering cost A t , procurement cost, C t and holding cost H t in period t. The dynamic lot-sizing problem is one of scheduling procurement Q t in each period in order to meet demand and minimize cost. The Wagner-Whitin algorithm for dynamic lot sizing has often been misunderstood as requiring inordinate computational time and storage requirements. We present an efficient computer implementation of the algorithm which requires low core storage, thus enabling it to be potentially useful on microcomputers. The recursive computations can be stated as follows: M jk =A j +C j Q j + ∑ k−1 t=j H t ∑ k r=t+1 D r F k = min 1⩽j⩽k [F j +M jk ]; F 0 =0 where M jk is the cost incurred by procuring in period j for all periods j through k, and F k is the minimal cost for periods 1 through k. Our implementation relies on the following observations regarding these computations: M j,k =A j +C j D j M j,k+1 =M jk +D k+1 (C j + ∑ k t=j H t , k⩽j Using this recursive relationship, the number of computations can be greatly reduced. Specifically, 3 2 N 2 − 1 2 N 2 additions and 1 2 N 2 + 1 2 N multiplications are required. This is insensitive to the data. A FORTRAN implementation on an Amdahl 470 yielded computation times (in 10 −3 seconds) of T = −.249 + .0239N + .00446N 2 . Problems with N = 500 were solved in under two seconds.

Corporate social responsibility: Implications for performance excellence

Corporate social responsibility has been an element of the Malcolm Baldrige Criteria for Performance Excellence since its inception in 1988. The Baldrige Criteria provide a framework for the design and improvement of high-performing organisations; as such, it implies that corporate social responsibility is an important factor for achieving performance excellence. Corporate social responsibility has garnered much attention from researchers over the past several decades, with most questions focusing on whether a company that is socially responsible is more likely to be financially successful. This paper examines the underlying corporate social responsibility value proposition within the Baldrige Criteria in comparison with current academic thought. We frame corporate social responsibility in terms of the underlying theories of firm management, review current academic thought and research, and draw conclusions on the relevance of corporate social responsibility for performance excellence in the Baldrige criteria. We conclude that even without direct, measurable empirical evidence, there is support in the literature that engaging in corporate social responsibility has a significant impact on performance.

Maximum flow in probabilistic graphs‐the discrete case

Frank and Frisch have considered the problem of determining the maximum flow probability distribution in networks where each branch has capacity that is a continuous random variable. In this paper, we consider the branch capacity distributions to be discrete and investigate some theoretical properties of the problem under this assumption.

Critical Linkages in the Baldrige Award Criteria: Research Models and Educational Challenges

In this article, a causal model that describes the key linkages in the Baldrige Award criteria for performance excellence framework is proposed. This model provides significant research opportunities for further theoretical modeling and empirical testin..

Methylprednisolone acetate does not cause inflammatory changes in the epidural space.

Few studies have examined the possible adverse effects that epidural injection of depot corticosteroid preparations may have on meningeal membranes and nervous tissue. Thirty-six healthy adult white rabbits received 0.3 ml/kg epidural injections of either lactated Ringers solution (negative control group), 1% lidocaine containing methylprednisolone acetate (study group), or normal saline containing talc (positive control group). Animals were killed either 4 or 10 days after injection and stained sections of the spinal cord and meningeal membranes were examined by light microscopy. In all animals that received either lactated Ringers solution or lidocaine with methylprednisolone acetate, microscopic examination of specimens taken from the L5-L6 interspace revealed no white cell infiltrates and no fibroblastic activity. All animals that received epidural injections of normal saline containing talc had marked infiltration of tissue macrophages in the epidural space. There was no thickening of the meningeal membranes or nerve roots in any animal. The complete lack of inflammatory changes and meningeal thickening demonstrated in this pilot study helps to confirm the safety of methylprednisolone acetate when injected into the epidural space.