An assessment of GRAI Grids and their use in the Strathclyde Integration Method

The purpose of this paper is to present a critical assessment of GRAI Grids as a tool for improved manufacturing integration. GRAI Grids, a key component of the GRAI approach, form an integral part of the Strathclyde Integration Method SIM for manufacturing integration. The contribution of the paper is thus to provide a 'third party' view of the effectiveness of GRAI Grids as a modelling tool. The paper presents a brief overview of the GRAI approach, concentrating particularly on the Grids, and an overview of SIM, showing how GRAI Grids are used. The main section of the paper presents an assessment and critique of GRAI Grids. Several benefits and limitations of the Grid as used in SIM and some suggestions for extensions are presented. The paper concludes that the use of the GRAI Grid, within a methodology, provides a unique insight into the behaviour and design of manufacturing information systems and that those who criticize the technique perhaps do so from a lack of awareness of its concepts, principles and advantages.     

Decision Making Under Risk: A Comparison of Bayesian and Fuzzy Set Methods

A classical decision problem is considered where a decision maker is to choose one of a number of actions each offering different consequences. The outcome from a choice of action is uncertain because it depends on the existing state of Nature. Also, the outcome, once an action and state of Nature are specified, may be a vector or a random vector. The decision maker employs both Bayesian methods and fuzzy set techniques to handle the uncertainties. The decision maker is also allowed to use multiple, possibly conflicting, goals in order to determine his best strategy. The Bayesian method produces a set of undominated strategies to choose from, whereas the fuzzy set technique usually produces a unique optimal strategy.     

A 14-h night-shift in the control room of a fire brigade

All 29 operators in the control room of a fire brigade performed test sessions during work and leisure time at 2-h intervals on a day with a 14-h night-shift, a day off and a day with a 10-h morning shift. The test sessions consisted of a visual search choice reaction time test and two Sternberg memory search tests (1 or 5 letters had to be memorized). Furthermore, the operators recorded their oral temperature and their subjective alertness before each test session. The subject also kept a diary of work and sleep times for 14 days. The circadian rhythm of body temperature was hardly changed by a single night-shift. Parallel to the body temperature, the subjective alertness fell significantly during the night-shift reaching a minimum value at 06:00 h. The mean reaction times increased non-significantly at the end of the night-shift and the results of the two Sternberg memory search tests showed no significant trends. The sleep of the operators after the night-shift was on average reduced to 5 hs 34 min. The results of subjective rating of alertness and reaction time test are interpreted as effects of the combined influences of circadian rhythmicity, sleep loss and time on professional task. Most results support the conclusion that a 14-h night-shift without extensive breaks is not acceptable.     

ORTHOGONAL INFORMATION STRUCTURES—A MODEL TO EVALUATE THE INFORMATION PROVIDED BY A SECOND OPINION

The paper discusses the value of information when a number of independent sources provide information related to a common set of states of nature. The starting point is the information economic model of information structures. The model is augmented to represent independence of informational sources by means of orthogonality of the information structures. A new mathematical operator, orthogonal product, is defined and its properties are probed. It is shown that this operator maintains some mathematical properties such as closure, association, unity element, null element, and so forth. It is demonstrated how the orthogonal product represents the notion of multisource information. The paper proves that an orthogonal product is generally more informative than its multipliers, namely, if cost is not considered a constraining factor, then there is a nonnegative value to obtaining a second opinion. An appendix to the paper expands this result to a case of partially dependent signals. The paper concludes with a numerical example and a discussion of the model's applicability for practical problems such as cost estimates.     

A physician's view from the Hill

Rarely do physicians have the opportunity to participate in our political system on a day-to-day basis. The Robert Wood Johnson Health Policy Fellowship, a one-year program for mid-career medical professionals, provides just such an experience. The Fellows begin with a two- to three-month orientation phase before selecting a congressional work assignment. As a member of a congressional staff, a Fellow has the opportunity to learn from, as well as contribute to, the legislative process. The health policy experience provides another tool to complement the clinical and management expertise of the physician executive.     

A PAVEMENT MANAGEMENT DECISION SUPPORT SYSTEM

We present a pavement management expert system developed by the University of Wisconsin-Madison and implemented within a geographical information system for the Wisconsin Department of Transportation. The system uses pavement data regularly collected on the state's 12,000 miles of highway to assist engineers, planners, and budget analysts' management decisions about pavements to be included in 6-year improvement and 3-year maintenance programs. The system has a three-layer architecture. The lowest level suggests treatments for each of a large number of small segments of highway. The middle layer aggregates segments, suggests alternative treatments, and estimates the cost of each. The top layer prioritizes the projects and incorporates them into intermediate-range plans. The geographical information system environment enables integration of existing databases within the system using a topologically structured geographic database and specialized software.     

A Unique Solution for the Nucleolus in Accounting Allocations*

The nucleolus method has been suggested in the literature as a means for accounting decision makers to allocate joint costs in situations where entities share a common resource. The nucleolus has the advantage, vis-à-vis other methods, of maximizing the benefit to the least-well-off entity or groups of entities, and therefore reducing the possibility that one or more entities may desire to withdraw from the sharing arrangement. The nucleolus is basically a linear programming model. Because of its formulation, the nucleolus may yield multiple optimal solutions. No reformulation of the nucleolus seems to exist to overcome this problem The minimum total propensity to disrupt (MTPD) is suggested as an extension of the nucleolus to identify unique values for allocations with multiple solutions. The MTPD, while exhibiting deficiencies as a stand-alone method, is similar in overall objective to the nucleolus and its mathematical function possesses a unique minimum. It is therefore the logical method for identifying a unique nucleolus solution. The use of the MTPD extension is critically examined through a representative application.     

Decision Theory Applied to an Instrumental Variables Model

This paper applies some general concepts in decision theory to a simple instrumental variables model. There are two endogenous variables linked by a single structural equation; k of the exogenous variables are excluded from this structural equation and provide the instrumental variables (IV). The reduced‐form distribution of the endogenous variables conditional on the exogenous variables corresponds to independent draws from a bivariate normal distribution with linear regression functions and a known covariance matrix. A canonical form of the model has parameter vector (ρ, φ, ω), where φis the parameter of interest and is normalized to be a point on the unit circle. The reduced‐form coefficients on the instrumental variables are split into a scalar parameter ρand a parameter vector ω, which is normalized to be a point on the (k−1)‐dimensional unit sphere; ρmeasures the strength of the association between the endogenous variables and the instrumental variables, and ωis a measure of direction. A prior distribution is introduced for the IV model. The parameters φ, ρ, and ωare treated as independent random variables. The distribution for φis uniform on the unit circle; the distribution for ωis uniform on the unit sphere with dimension k‐1. These choices arise from the solution of a minimax problem. The prior for ρis left general. It turns out that given any positive value for ρ, the Bayes estimator of φdoes not depend on ρ; it equals the maximum‐likelihood estimator. This Bayes estimator has constant risk; because it minimizes average risk with respect to a proper prior, it is minimax. The same general concepts are applied to obtain confidence intervals. The prior distribution is used in two ways. The first way is to integrate out the nuisance parameter ωin the IV model. This gives an integrated likelihood function with two scalar parameters, φand ρ. Inverting a likelihood ratio test, based on the integrated likelihood function, provides a confidence interval for φ. This lacks finite sample optimality, but invariance arguments show that the risk function depends only on ρand not on φor ω. The second approach to confidence sets aims for finite sample optimality by setting up a loss function that trades off coverage against the length of the interval. The automatic uniform priors are used for φand ω, but a prior is also needed for the scalar ρ, and no guidance is offered on this choice. The Bayes rule is a highest posterior density set. Invariance arguments show that the risk function depends only on ρand not on φor ω. The optimality result combines average risk and maximum risk. The confidence set minimizes the average—with respect to the prior distribution for ρ—of the maximum risk, where the maximization is with respect to φand ω.     

Assessing Cross-Media Impacts: A Comparative Risk Approach

The Oregon Department of Environmental Quality has developed a Cross-Media Comparative Risk Assessment model to address certain regulatory concerns. The model generates a Human and Ecological Risk Index for a facility releasing toxins into the environment. The risk indices are based on chemical fate and transport predictions, toxicity, population density, and ecological sensitive areas. The model can be used to rank facilities for inspection or as a tool to assess the progress of pollution prevention programs. Regulatory permitting departments can use the model to address the cross-media transfer of pollutants from one environmental compartment to another. The versatility of the model allows adaptation to each specific users needs.     

A new prototype system for optimized job shop scheduling

Optimal scheduling of shopfloor activities in an environment of discrete part manufacturing is discussed. The scheduling problem is a well known NP complete one. The main part, the sequencing problem, has been tackled using two techniques: virtual resources identification and taboo search heuristics. The first approach allowed the authors to reduce the complexity of the sequencing from a job shop to a general flow shop problem. On the other hand, the search for an optimal solution, with respect to a fixed strategy, has been achieved via the taboo search. A synthesis of the results of a large number of tests is presented as well as the results of an application to a real case. The latter is shown in comparison with the output of the system being presently used in the examined factory.     

A 14-h night-shift in the control room of a fire brigade

Abstract

All 29 operators in the control room of a fire brigade performed test sessions during work and leisure time at 2-h intervals on a day with a 14-h night-shift, a day off and a day with a 10-h morning shift. The test sessions consisted of a visual search choice reaction time test and two Sternberg memory search tests (1 or 5 letters had to be memorized). Furthermore, the operators recorded their oral temperature and their subjective alertness before each test session. The subject also kept a diary of work and sleep times for 14 days. The circadian rhythm of body temperature was hardly changed by a single night-shift. Parallel to the body temperature, the subjective alertness fell significantly during the night-shift reaching a minimum value at 06:00 h. The mean reaction times increased non-significantly at the end of the night-shift and the results of the two Sternberg memory search tests showed no significant trends. The sleep of the operators after the night-shift was on average reduced to 5 hs 34 min. The results of subjective rating of alertness and reaction time test are interpreted as effects of the combined influences of circadian rhythmicity, sleep loss and time on professional task. Most results support the conclusion that a 14-h night-shift without extensive breaks is not acceptable.     

Zur Integration ehrenamticher Mitarbeiter/innen in Organisationen

The integration of volunteers in organizations On the background of the current changes in the general work conditions, a professional volunteer management in organizations is necessary. The author demonstrates, that in organizations a professional staff with management competences is a precondition. The peculiarities in leading volunteers are explained. The focus of the article are suggestions to a personnel development, in order to instruct and to attend individual employees or larger organizational units for a successful cooperation with volunteers. A special training as well as coaching and organizational development are delineated.     

Key success factors when implementing a green-manufacturing system

This study proposes a three-layer assessment model to evaluate the performance of a green-manufacturing system (GMS) and identify the key success factors of its real-world implementation. The top layer of the model includes three dimensions – green design, green-manufacturing process and green packaging. The second and third layers include ten strategic subjects and 74 assessment factors, respectively. The weights in each layer are collected via a questionnaire and calculated using the analytical network process (ANP). Based on the ANP, the five key success factors for implementing the GMS in a company are proportion of non-toxic materials, compliance with eco-ordinances, proportion of biodegradable materials, environmental pollution per product and extent of process pollution. The practicality of the proposed model is demonstrated by evaluating three companies that produce similar products and share similar business models. The proposed model provides a valuable reference for real-world implementation of the GMS.     

Consolidation and fragmentation in environmental scanning: A review and research agenda

Environmental scanning is a broadly defined concept, having first received attention from scholars in the late 1960s. Over the years a number of similar and overlapping constructs have emerged in management literature. The aim of this study, via a systematic review and thematic analysis of relevant empirical research, is to consolidate foundation environmental scanning knowledge, demonstrate how scanning research has developed and fragmented over time, and propose an agenda for future research. The first contribution of our review is a new typology of environmental scanning research made up of five discrete research views, which provides a more comprehensive and contemporary overview of the field than previous studies. The second is a proposed agenda for future research that explicitly acknowledges the role of technology, an area that is presently underdeveloped in foundation scanning literature. The third contribution is to signpost future directions for research on scanning and organisational performance using a number of theoretical perspectives. The overall outcome of our review is to move scanning research on from increasingly incremental contributions concerned with context to a place where the changing role of technology and the mechanisms through which environmental scanning contributes to competitive advantage can be more thoroughly understood.     

Learning in and from projects: the learning modes and a learning capability model

Abstract

The notion of ‘project delivery’ is well embedded in and across the management and organizational sciences literature – generating a narrative that reflects and recognizes the instrumental nature of projects and programmes in strategy execution. Project management, as a distinct and well-established body of research enquiry, has increasingly sought to focus our attention on the impacts of complexity, risk and uncertainty in projects; the corollary being a desideratum to strengthen our theoretical understanding of how insight and learning from projects may influence improvements to organizational efficiency. The wider literature suggests that organizational learning remains a challenging proposition, particularly in the context of organizations operating in environments of high complexity. In this paper, we enhance the conversation on organizational learning through a series of case studies, generating evidence of thirteen ‘learning modes’. The paper proposes that mature organizations tend to exhibit a greater number of learning modes and that there is a tendency to capture and socialize knowledge with a greater emphasis on the context of the learning situation rather than the learning artefact in isolation. The empirical evidence gathered in this paper forms the basis of a capability model, characterized by the thirteen modes of learning. The model intimates that learning occurs, and is more effective, when knowledge and information are enacted in practice through the learning modes which form a nucleus of the organizational learning capability. The research concludes with a 'call to action' that emphasizes the strategic importance of learning practices and routines in project oriented-organizations.     

A decision support methodology for strategic planning in maritime transportation

This paper presents a decision support methodology for strategic planning in tramp and industrial shipping. The proposed methodology combines simulation and optimization, where a Monte Carlo simulation framework is built around an optimization-based decision support system for short-term routing and scheduling. The simulation proceeds by considering a series of short-term routing and scheduling problems using a rolling horizon principle where information is revealed as time goes by. The approach is flexible in the sense that it can easily be configured to provide decision support for a wide range of strategic planning problems, such as fleet size and mix problems, analysis of long-term contracts and contract terms. The methodology is tested on a real case for a major Norwegian shipping company. The methodology provided valuable decision support on important strategic planning problems for the shipping company.     

A 14-h night-shift in the control room of a fire brigade

All 29 operators in the control room of a fire brigade performed test sessions during work and leisure time at 2-h intervals on a day with a 14-h night-shift, a day off and a day with a 10-h morning shift. The test sessions consisted of a visual search choice reaction time test and two Sternberg memory search tests (1 or 5 letters had to be memorized). Furthermore, the operators recorded their oral temperature and their subjective alertness before each test session. The subject also kept a diary of work and sleep times for 14 days. The circadian rhythm of body temperature was hardly changed by a single night-shift. Parallel to the body temperature, the subjective alertness fell significantly during the night-shift reaching a minimum value at 06:00 h. The mean reaction times increased non-significantly at the end of the night-shift and the results of the two Sternberg memory search tests showed no significant trends. The sleep of the operators after the night-shift was on average reduced to 5 hs 34 min. The results of subjective rating of alertness and reaction time test are interpreted as effects of the combined influences of circadian rhythmicity, sleep loss and time on professional task. Most results support the conclusion that a 14-h night-shift without extensive breaks is not acceptable.     

The evolution and problems of model management research

Models are a key resource for organizational decision making. The diversity, complexity, and reusability of this resource result in the need for model management systems. The construction of a model management system involves a modeling task dimension and a design level dimension. The modeling task dimension consists of model formulation, model representation, and model processing. The design level dimension addresses the architectural requirements of a system from a user's standpoint and a computer system's standpoint.The numerous architectures suggested in the model management systems literature address isolated areas identified by these dimensions. The research surveyed in this paper indicates that the primary focus has been on the system view of model representation. Before model management systems can be widely used in organizations, model management researchers must explore systems that address all areas of the task and design level dimensions.In this paper, we identify and justify the necessary dimensions of model management research. Next, the existing model management research is critically reviewed. Finally, neglected research areas are discussed, and investigations necessary for the development of integrated model management systems are suggested.     

摩擦市场中允许卖空的最优投资组合选择

资本市场的一个重要特征就是存在不确定因素,为了衡量其导致的风险,本文提出基于绝对偏差的新型函数,在一个存在摩擦的资本市场中构造均值-绝对离差(mean-absolute deviation,MAD)投资组合选择模型.该模型结构特殊性使其转化为线性规划问题,从而可利用单纯型法求解.实证分析比较了不同风险函数下投资组合的有效前沿,并验证了该方法的有效性.