Siting Bio-Samplers in Buildings

We describe a probabilistic approach to siting samplers for detecting accidental or intentional releases of biological material. In the face of uncertainty and variability in the release conditions, we place samplers in order to maximize the probability of detecting a release from among a suite of realistic scenarios. The scenarios may differ in any unknown, for example, the release size or location, weather, mode of building operation, etc. In an illustrative example, we apply the algorithm to a hypothetical 24-room commercial building, finding optimal networks for a variety of assumed sampler types. The results show how sampler characteristics, most importantly the detection limit, affect the network performance. This suggests using the probabilistic approach to guide the priorities of sampler designers, as well as to site samplers in specific buildings.     

Application Development Using Fault Data

We develop a general model for software development process and propose a policy to manage system coordination using system fault reports (e.g., interface inconsistencies, parameter mismatches, etc.). These reports are used to determine the timing of coordination activities that remove faults. We show that under an optimal policy, coordination should be performed only if a “threshold” fault count has been exceeded. We apply the policy to software development processes and compare the management of those projects under different development conditions. A series of numerical experiments are conducted to demonstrate how the fault threshold policy needs to be adjusted to changes in system complexity, team skill, development environment, and project schedule. Moreover, we compare the optimal fault threshold policy to an optimal release‐based policy. The release‐based policy does not take into account fault data and is easier to administer. The comparisons help to define the range of project parameters for which observing fault data can provide significant benefits for managing a software project.     

Anticipating or Accommodating to Public Concern? Risk Amplification and the Politics of Precaution Reexamined

Regulatory use of the precautionary principle (PP) tends to be broadly characterized either as a responsible approach for safeguarding against health and environmental risks in the face of scientific uncertainties, or as “state mismanagement” driven by undue political bias and public anxiety. However, the “anticipatory” basis upon which governments variably draw a political warrant for adopting precautionary measures often remains ambiguous. Particularly, questions arise concerning whether the PP is employed preemptively by political elites from the “top down,” or follows from more conventional democratic pressures exerted by citizens and other stakeholders from the “bottom up.” This article elucidates the role and impact of citizen involvement in the precautionary politics shaping policy discourse surrounding the U.K. government's “precautionary approach” to mobile telecommunications technology and health. A case study is presented that critically reexamines the basis upon which U.K. government action has been portrayed as an instance of anticipatory policy making. Findings demonstrate that the use of the PP should not be interpreted in the preemptive terms communicated by U.K. government officials alone, but also in relation to the wider social context of risk amplification and images of public concern formed adaptively in antagonistic precautionary discourse between citizens, politicians, industry, and the media, which surrounded cycles of government policy making. The article discusses the sociocultural conditions and political dynamics underpinning public influence on government anticipation and responsiveness exemplified in this case, and concludes with research and policy implications for how society subsequently comes to terms with the emergence and precautionary governance of new technologies under conflict.     

Some Limitations of Qualitative Risk Rating Systems

Qualitative systems for rating animal antimicrobial risks using ordered categorical labels such as “high,”“medium,” and “low” can potentially simplify risk assessment input requirements used to inform risk management decisions. But do they improve decisions? This article compares the results of qualitative and quantitative risk assessment systems and establishes some theoretical limitations on the extent to which they are compatible. In general, qualitative risk rating systems satisfying conditions found in real‐world rating systems and guidance documents and proposed as reasonable make two types of errors: (1) Reversed rankings, i.e., assigning higher qualitative risk ratings to situations that have lower quantitative risks; and (2) Uninformative ratings, e.g., frequently assigning the most severe qualitative risk label (such as “high”) to situations with arbitrarily small quantitative risks and assigning the same ratings to risks that differ by many orders of magnitude. Therefore, despite their appealing consensus‐building properties, flexibility, and appearance of thoughtful process in input requirements, qualitative rating systems as currently proposed often do not provide sufficient information to discriminate accurately between quantitatively small and quantitatively large risks. The value of information (VOI) that they provide for improving risk management decisions can be zero if most risks are small but a few are large, since qualitative ratings may then be unable to confidently distinguish the large risks from the small. These limitations suggest that it is important to continue to develop and apply practical quantitative risk assessment methods, since qualitative ones are often unreliable.     

Lot‐sizing Decisions Under Limited‐time Price Reduction*

We consider the optimal lot‐sizing policy for an inventoried item when the vendor offers a limited‐time price reduction. We use the discounted cash flow (DCF) approach in our analysis, thereby eliminating the sources of approximation found in most of the earlier studies that use an average annual cost approach. We first characterize the optimal lot‐sizing policies and their properties, then develop an algorithm for determining the optimal lot sizes. We analytically demonstrate that the lot sizes derived using an average annual cost approach for the different variants of the problem are, in general, larger than the DCF optimum. While DCF analysis is more rigorous and yields precise lot sizes, we recognize that the associated mathematical models and the solution procedure are rather complex. Since simple and easy‐to‐understand policies have a strong practical appeal to decision makers, we propose a DCF version of a simple and easy‐to‐implement heuristic called the “Early Purchase” (EP) strategy and discuss its performance. We supplement our analytical developments with a detailed computational analysis and discuss the implications of our findings for decision making.     

The economic case for “High performance buildings”

A well-planned approach to building design and development can lead to the construction of facilities that are green “both ways”—that is, facilities that are not only more environmentally-benign, but also facilities that are more economically-beneficial for their owners and operators than those based on more traditional designs, processes, and materials. “Green buildings,” or “high performance buildings” as they are increasingly being called, are being commissioned in growing numbers. As more of these facilities come on line, the data supporting the economic case for them is also growing, and that case is very compelling. In this article, the author examines comparisons between traditional and “high performance” buildings to highlight the long-term competitive advantage.     

Using case studies as an approach for conducting agribusiness research

Case study research is increasingly important in agricultural economics as a means of collecting data, and building and testing theory. Case study research has a prescribed set of objectives, espitemology, methodology, and methods that have been developed and tested in a wide range of scholarly and problem-solving situations. This article reviews these fundamentals and then demonstrates the case study approach within the context of an agribusiness research project. This application exemplifies how case study research is capable of generating a robust, comprehensive array of “knowledge” about complex, highly interdependent and dynamic economic and social phenomena.     

Simultaneous Search

We introduce and solve a new class of “downward‐recursive” static portfolio choice problems. An individual simultaneously chooses among ranked stochastic options, and each choice is costly. In the motivational application, just one may be exercised from those that succeed. This often emerges in practice, such as when a student applies to many colleges or when a firm simultaneously tries several technologies. We show that such portfolio choice problems quite generally entail maximizing a submodular function of finite sets—which is NP‐hard in general. Still, we show that a greedy algorithm finds the optimal set, finding first the best singleton, then the best single addition to it, and so on. We show that the optimal choices are “less aggressive” than the sequentially optimal ones, but “more aggressive” than the best singletons. Also, the optimal set in general contains gaps. We provide some comparative statics results on the chosen set.     

Conceptualizing Effects of Office Information Systems: A Methodology and Application for the Study of Alpha,Beta, and Gamma Changes*

This article applies the concepts of alpha, beta, and gamma changes to test whether the implementation of a new office information system with networking capabilities changes the way organizational members conceptualize office work. The traditional approach (t-test) was used to measure alpha change and indicated little change in how effectively the respondents felt they performed eight generic office activities before implementation (T1) and nine months after implementation (T2). However, considerable change was detected between effectiveness reported at T1 and a retrospective assessment of T1 effectiveness reported at T2 (called “then” assessments). Strong change was also detected between “then” assessments and T2 effectiveness reported at T2, indicating beta change. Multiple hierarchical tests showed that most of the change was actually gamma change; the T2 and the “then” factor structures and covariances differed significantly. This study supports propositions that using computers to accomplish organizational work may be associated with different conceptualizations of work, which may create ambiguity and uncertainty if training and management policies do not respond appropriately. Finally, this study provides an expanded version of a prior solution to detecting alpha, beta, and gamma changes.     

The Value of Environmental Information without Control of Subsequent Decisions

The standard value of information approach of decision analysis assumes that the individual or agency that collects the information is also in control of the subsequent decisions based on the information. We refer to this situation as the “value of information with control (VOI‐C).” This paradigm leads to powerful results, for example, that the value of information cannot be negative and that it is zero, when the information cannot change subsequent decisions. In many real world situations, however, the agency collecting the information is different from the one that makes the decision on the basis of that information. For example, an environmental research group may contemplate to fund a study that can affect an environmental policy decision that is made by a regulatory organization. In this two‐agency formulation, the information‐acquiring agency has to decide, whether an investment in research is worthwhile, while not being in control of the subsequent decision. We refer to this situation as “value of information without control (VOI‐NC).” In this article, we present a framework for the VOI‐NC and illustrate it with an example of a specific problem of determining the value of a research program on the health effects of power‐frequency electromagnetic fields. We first compare the VOI‐C approach with the VOI‐NC approach. We show that the VOI‐NC can be negative, but that with high‐quality research (low probabilities of errors of type I and II) it is positive. We also demonstrate, both in the example and in more general mathematical terms, that the VOI‐NC for environmental studies breaks down into a sum of the VOI‐NC due to the possible reduction of environmental impacts and the VOI‐NC due to the reduction of policy costs, with each component being positive for low environmental impacts and high‐quality research. Interesting results include that the environmental and cost components of the VOI‐NC move in opposite directions as a function of the probability of environmental impacts and that VOI‐NC can be positive, even though the probability of environmental impacts is zero or one.     

Workload Control and Order Release: A Lean Solution for Make‐to‐Order Companies

Protecting throughput from variance is the key to achieving lean. Workload control (WLC) accomplishes this in complex make‐to‐order job shops by controlling lead times, capacity, and work‐in‐process (WIP). However, the concept has been dismissed by many authors who believe its order release mechanism reduces the effectiveness of shop floor dispatching and increases work center idleness, thereby also increasing job tardiness results. We show that these problems have been overcome. A WLC order release method known as “LUMS OR” (Lancaster University Management School order release) combines continuous with periodic release, allowing the release of work to be triggered between periodic releases if a work center is starving. This paper refines the method based on the literature (creating “LUMS COR” [Lancaster University Management School corrected order release]) before comparing its performance against the best‐performing purely periodic and continuous release rules across a range of flow directions, from the pure job shop to the general flow shop. Results demonstrate that LUMS COR and the continuous WLC release methods consistently outperform purely periodic release and Constant WIP. LUMS COR is considered the best solution in practice due to its excellent performance and ease of implementation. Findings have significant implications for research and practice: throughput times and job tardiness results can be improved simultaneously and order release and dispatching rules can complement each other. Thus, WLC represents an effective means of implementing lean principles in a make‐to‐order context.     

As Public Goes Private, Social Emerges: The Rise of Social Enterprise

This article explores the relationship between social enterprise and a much-longer known set of arrangements generally comprehended as “public enterprise” (or “state-owned enterprise”). It considers the decline in some contexts in the use of, and interest in, public enterprise that reflects the impact of the privatization movement, and the rise of social enterprise as an alternative form—with speculation about cause-and-effect connections between these movements. An exploration of this sort may contribute in the longer term to a better understanding of the place of “public”, “social” and “community” values and structures within the general framework of governance.     

A Model of the Consumption Response to Fiscal Stimulus Payments

A wide body of empirical evidence finds that approximately 25 percent of fiscal stimulus payments (e.g., tax rebates) are spent on nondurable household consumption in the quarter that they are received. To interpret this fact, we develop a structural economic model where households can hold two assets: a low‐return liquid asset (e.g., cash, checking account) and a high‐return illiquid asset that carries a transaction cost (e.g., housing, retirement account). The optimal life‐cycle pattern of portfolio choice implies that many households in the model are “wealthy hand‐to‐mouth”: they hold little or no liquid wealth despite owning sizable quantities of illiquid assets. Therefore, they display large propensities to consume out of additional transitory income, and small propensities to consume out of news about future income. We document the existence of such households in data from the Survey of Consumer Finances. A version of the model parameterized to the 2001 tax rebate episode yields consumption responses to fiscal stimulus payments that are in line with the evidence, and an order of magnitude larger than in the standard “one‐asset” framework. The model's nonlinearities with respect to the rebate size and the prevailing aggregate economic conditions have implications for policy design.     

A Queueing Theoretic Approach to Set Staffing Levels in Time‐Dependent Dual‐Class Service Systems*

This article addresses the optimal staffing problem for a nonpreemptive priority queue with two customer classes and a time‐dependent arrival rate. The problem is related to several important service settings such as call centers and emergency departments where the customers are grouped into two classes of “high priority” and “low priority,” and the services are typically evaluated according to the proportion of customers who are responded to within targeted response times. To date, only approximation methods have been explored to generate staffing requirements for time‐dependent dual‐class services, but we propose a tractable numerical approach to evaluate system behavior and generate safe minimum staffing levels using mixed discrete‐continuous time Markov chains (MDCTMCs). Our approach is delicate in that it accounts for the behavior of the system under a number of different rules that may be imposed on staff if they are busy when due to leave and involves explicitly calculating delay distributions for two customer classes. Ultimately, we embed our methodology in a proposed extension of the Euler method, coined Euler Pri, that can cope with two customer classes, and use it to recommend staffing levels for the Welsh Ambulance Service Trust (WAST).     

Designing Supply Contracts Considering Profit Targets and Risk

Managers at all stages of a supply chain are concerned about meeting profit targets. We study contract design for a buyer–supplier supply chain, with each party maximizing expected profit subject to a chance constraint on meeting his respective profit target. We derive the optimal contract form (across all contract types) with randomized and deterministic payments. The best contract has the property that, if the chance constraints are binding, at most one party fails to satisfy his profit target for any given demand realization. This implies that “least risk sharing,”that is, minimizing the probability of outcomes for which both parties fail to achieve their profit targets, is optimal, contrary to the usual expectations of “risk sharing.” We show that an optimal contract can possess only two of the following three properties simultaneously: (i) supply chain coordination, (ii) truth‐telling, and (iii) non‐randomized payments. We discuss methods to mitigate the consequent implementation challenges. We also derive the optimal contract form when chance constraints are incorporated into several simpler and easier‐to‐implement contracts. From a numerical study, we find that an incremental returns contract (in which the marginal rebate rate depends on the return quantity) performs quite well across a relatively broad range of conditions.     

„Opportunity coaching“: Ein ermutigender Weg in die Coaching-Zukunft

?Opportunity coaching“ — a powerful way into coaching future This article stresses a powerful coaching approach: to work on a client’s resources, on a client’s potential improvement, oriented at a client’s future possibilities, chances and “opportunities”. Starting from a dialectic “as well as” paradigm: seeing strength and weaknesses, past and future, problems and possibilities not being mutual exclusions but parts of an holistic entity, the author elaborates core aspects and approaches of “opportunity coaching” and reports examples out of his coaching experience.     

When Is a Risk Assessment Deficient According to an Uncertainty‐Based Risk Perspective?

The Petroleum Safety Authority Norway (PSA‐N) has recently adopted a new definition of risk: “the consequences of an activity with the associated uncertainty.” The PSA‐N has also been using “deficient risk assessment” for some time as a basis for assigning nonconformities in audit reports. This creates an opportunity to study the link between risk perspective and risk assessment quality in a regulatory context, and, in the present article, we take a hard look at the term “deficient risk assessment” both normatively and empirically. First, we perform a conceptual analysis of how a risk assessment can be deficient in light of a particular risk perspective consistent with the new PSA‐N risk definition. Then, we examine the usages of the term “deficient” in relation to risk assessments in PSA‐N audit reports and classify these into a set of categories obtained from the conceptual analysis. At an overall level, we were able to identify on what aspects of the risk assessment the PSA‐N is focusing and where deficiencies are being identified in regulatory practice. A key observation is that there is a diversity in how the agency officials approach the risk assessments in audits. Hence, we argue that improving the conceptual clarity of what the authorities characterize as “deficient” in relation to the uncertainty‐based risk perspective may contribute to the development of supervisory practices and, eventually, potentially strengthen the learning outcome of the audit reports.     

Selbstreflexivität – Annäherungen an eine zentrale Haltung in Coaching- und Beratungsprozessen

This article explores “self-reflexivity” as a key competence and general attitude in all contexts of coaching and supervision. Three main perspectives are used approaching self-reflexivity: the “where from”, “what for” and “how-to”. Thus starting from etymology the importance of the subject in the practice of coaches and counselors is explored. Based on two models it is shown what kind of interaction between client and coach is beneficial when wanting to activate self-reflexivity. The article is rounded up by a note on self-care—one important aspect of self-reflexivity.     

Beyond Positive Reinforcement

Abstract

This article comments on the need to recognize that OBM already is a “positive psychology” for many more reasons than just that it embraces positive reinforce as a cornerstone of workplace improvement. This paper suggests there are at least 10 ways in which OBM constitutes a distinctly “positive” and humanizing approach to management practices. These ways are enumerated and briefly reviewed.     

Cost‐Benefit Analysis of Passive Fire Protections in Road LPG Transportation

The cost‐benefit evaluation of passive fire protection adoption in the road transport of liquefied petroleum gas (LPG) was investigated. In a previous study, mathematical simulations of real scale fire scenarios proved the effectiveness of passive fire protections in preventing the “fired” boiling liquid expanding vapor explosion (BLEVE), thus providing a significant risk reduction. In the present study the economical aspects of the adoption of fire protections are analyzed and an approach to cost‐benefit analysis (CBA) is proposed. The CBA model is based on the comparison of the risk reduction due to fire protections (expressed in monetary terms by the value of a statistical life) and the cost of the application of fire protections to a fleet of tankers. Different types of fire protections were considered, as well as the possibility to apply protections to the entire fleet or only to a part of it. The application of the proposed model to a real‐life case study is presented and discussed. Results demonstrate that the adoption of passive fire protections on road tankers, though not compulsory in Europe, can be economically feasible, thus representing a concrete measure to achieve control of the “major hazard accidents” cited by the European legislation.