The distribution of lead time demand is essential for determining reorder points in inventory systems. Usually, the distribution of lead time demand is approximated directly. However, in some cases it may be worthwhile to take the demand per unit time and lead time into account, particularly when specific information is available. This paper deals with the situation where a supplier, who produces on order in fixed production cycles, provides information on the status of the coming production run. The retailer can use this information to gain insight into the lead-time process. A fixed order (svQ) strategy is presented, with a set of reorder points sv depending on the time t until the first possible delivery, which is determined by the information of the supplier. A Markov model that analyzes a given (svQ) strategy is used to quantify the value of the information provided by the supplier. Some numerical examples show that the approach may lead to considerable cost savings compared to the traditional approach that uses only one single reorder point, based on a two-moments approximation. Using this numerical insight, the pros and cons of a more frequent exchange of information between retailers and suppliers can be balanced. 相似文献
The aim of a series of sessions on Company Case Studies, is to learn from practical experiences, to give feed back to researchers on applicability of theories, methods and techniques, and last but not least, to market ergonomics. In order to learn from case material, reports need to be easy accessible and well structured. System ergonomics provides such a structure. Usually a project is not done twice, i.e. with and without ergonomics. Therefore, it is not possible to make comparisons and determine the impact of ergonomics directly. A different approach is needed. It has been suggested at the IEA2006 World Congress, to compile a database of published case studies, each case to be reported in a fixed report format and critically reviewed to enable generalizing the outcomes. This paper proposes such a format. At the IEA2012 World Congress 40 case studies have been accepted, representing applied ergonomics cases in manufacturing, process industries, aviation and logistic systems. 相似文献
As most epidemiological surveys on sexual problems have not included assessment of associated distress, the principal aim of this study was to provide prevalence estimates of both DSM-IV-TR-defined (American Psychiatric Association [APA], 2000 American Psychiatric Association . ( 2000 ). Diagnostic and statistical manual of mental disorders , (4th ed., text rev.) . Washington , DC : Author .[Crossref], [Google Scholar]) and less commonly assessed sexual difficulties and dysfunction (e.g., lack of responsive sexual desire, lack of subjective arousal). A secondary aim was to obtain information about comorbidity between sexual desire and sexual arousal difficulties/dysfunction. This study comprised an online survey completed by 35,132 heterosexual Flemish men and women (aged 16 to 74 years). Results indicated that sexual dysfunctions were far less common than sexual difficulties, and some uncommonly assessed sexual problems (e.g., “lack of responsive desire” in women; “hyperactive sexual desire” in men) were quite prevalent. In women, there was a high comorbidity between “lack of spontaneous sexual desire” and “lack of responsive sexual desire”; between “lack of genital arousal” and “lack of subjective sexual arousal”; and between sexual desire and sexual arousal difficulties/dysfunctions. The implications of these findings for epidemiological research on sexual dysfunction and for the newly defined DSM-5 Female Sexual Interest/Arousal Disorder (APA, 2013 American Psychiatric Association . ( 2013 ). Diagnostic and statistical manual of mental disorders , (5th ed.) . Washington , DC : Author .[Google Scholar]) are discussed. 相似文献
Motivated by a case study of a company that produces car parts, we study the multi‐product economic lot scheduling problem for a hybrid production line with manufacturing of new products and remanufacturing of returned products. For this economic lot scheduling problem with returns (ELSPR), we consider policies with a common cycle time for all products, and with one manufacturing lot and one remanufacturing lot for each product during a cycle. For a given cycle time, the problem is formulated as a mixed integer linear programming (MIP) problem, which provides the basis for an exact solution. The application of this model for one of the core products of the case study company indicates a 16% reduction in cost compared to the current lot scheduling policy. 相似文献
The 1980s and 1990s have been decades of quitegood economic growth in North America and muchof Western Europe. But how have the fruits ofgrowth been shared? This paper reviews changingincome distributions in the U.S., Germany and theNetherlands. These three countries may be takenas exemplars and leading economic performers in``the three worlds of welfare capitalism''(Esping-Andersen, 1990). The U.S. is a liberalwelfare-capitalist state, Germany a corporatiststate, and the Netherlands (less clearly) asocial democratic welfare-capitalist state. Thepaper focuses particularly on income changes inthe bottom, middle and top quintiles and takesa ten year period into account.Previous analyses have shown that labor andmarket income dispersion are increasing, withincreased returns to human capital. Thepotential impact of government through thetax-transfer system has been largely ignored.All three governments redistribute income fromthe rich to the poor. However, the paper showsthat only the Dutch government hasredistributed sufficiently to ensure that thebottom quintile has gained along with others.In Germany and the U.S. the poorest quintile wasconsiderably worse off in absolute terms at theend of the decade.than the beginning. TheGerman government somewhat counteracted thetrend towards greater income dispersion byredistributing to the poorest quintile, so theloss of market income was partly compensated. In the U.S. the impact of government on thepoorest quintile stayed about the same, so thisgroup ended up with about the same decrease indisposable income as market income.The U.S., Germany and the Netherlands are theonly three countries for which ten or moreconsecutive years of panel data are available.The data come from the PSID-GSOEP EquivalentFile 1980-97 and from a comparable fileconstructed from the Dutch SEP data.
Profit‐maximizing firm owners who incentivize their managers with a bonus for process improvement create an intentional misalignment of their own objective and management attention. From the viewpoint of a single firm, such a local misalignment can never be profitable, but in this study we take a wider strategic perspective by investigating cost‐reducing process improvements of two firms competing in a Cournot market. We find that the use of a process improvement bonus (by firm A) can be profitable, by affecting the competitor's decision making. Informed about the reward structure at firm A, which provides an incentive for process improvement and thereby for increased production at that firm, the manager of the competing firm (B) is inclined to produce less if the owner of firm B only rewards profit. This leads to a higher profit for firm A. However, we also show that firm B's best strategy is to also offer a process improvement bonus, even if that firm is a cost laggard (with higher costs for process improvement), and that this leads to reduced profit for both firms in many situations unless one of them is sufficiently superior in its ability to improve processes. These results are robust for uncertain process improvement outcomes, multidimensional process improvement decisions, and information asymmetry in the owner–manager relationship. 相似文献
The purpose of the paper is to assess the theory that the downside risk insurance provided by more generous welfare states
generates long run efficiency gains, which counterbalance the short run efficiency losses caused by work disincentives in
these states (Feldstein 1974, 1976; Sinn 1995, 1996). Testing downside risk theory requires long term data, so the paper makes
use of the three longest running national socio-economic panel surveys. These are the American Panel Study of Income Dynamics
(PSID, 1968-), the German Socio-Economic Panel (1984-) and the Dutch Socio-Economic Panel (SEP, 1984-). The paper focusses
on prime age households (heads 25–59) and assesses their participation in and returns to adult education and job training.
Our results indicate some support for the theory in so far as Dutch and German prime age adults, living in more generous welfare
states, were much more likely than Americans to take the risk of foregoing current earnings and investing in additional education.
In all three countries returns on investment were substantial.
Consumers select a decision strategy in a purchase situation that best meets their goals for that situation. One of those possible goals is to obtain closure. The dimension need for closure (NFC) (vs. avoidance) reflects the desire for clear, definite, or unambiguous knowledge that will guide perception and action, as opposed to the undesirable alternative of ambiguity and confusion. The purpose of this study is to identify the influence of NFC on choice behaviour in a low involvement purchase situation. Both high (N=71) and low (N=71) NFC participants participated in a shopping experiment. In a simulated environment, participants were asked to choose repetitively between different brands within two low involvement product categories. We found significant differences between high and low NFC participants with regard to the amount of information sought, the amount of information used, the use of decision rules and the level of confidence in their decisions made. Marketing implications, limitations and directions for future research are also provided. 相似文献
Introduction of classical swine fever virus (CSFV) is a continuing threat to the pig production sector in the European Union. A scenario tree model was developed to obtain more insight into the main risk factors determining the probability of CSFV introduction (P(CSFV)). As this model contains many uncertain input parameters, sensitivity analysis was used to indicate which of these parameters influence model results most. Group screening combined with the statistical techniques of design of experiments and meta-modeling was applied to detect the most important uncertain input parameters among a total of 257 parameters. The response variable chosen was the annual P(CSFV) into the Netherlands. Only 128 scenario calculations were needed to specify the final meta-model. A consecutive one-at-a-time sensitivity analysis was performed with the main effects of this meta-model to explore their impact on the ranking of risk factors contributing most to the annual P(CSFV). The results indicated that model outcome is most sensitive to the uncertain input parameters concerning the expected number of classical swine fever epidemics in Germany, Belgium, and the United Kingdom and the probability that CSFV survives in an empty livestock truck traveling over a distance of 0-900 km. 相似文献