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This study proposes a genetic algorithm (GA)-based Material Handling Strategy Function (MHSF) method to increase the productivity of a TFT-LCD array fabrication to improve the traditional FIFO method in TFT-LCD fabrication by the reduction of the material handling for a Rail Guided Vehicle (RGV), because costs of material handling count up to about 50% of production costs. In this article, the MHSF is provided to help material handling commands choice, where a novel GA approach is used to adapt the weights of affecting factors in the function. Finally, to evaluate the performance of the proposed method, experiments using the data from a major TFT-LCD manufacturing plant in Taiwan have been carried out, and the results indicate that it can indeed reduce fabrication time and increase productivity. [ABSTRACT FROM AUTHOR]

This paper deals with local scheduling problems as part of a global process management policy. The industrial context is an automotive assembly plant. An automobile manufacturing process creates a list that schedules orders so as to optimize production costs. Such a list must respect the vast majority of shop-related constraints, notably those of the assembly shop, which are the hardest to schedule. This list also allows one to provide information to suppliers regarding the parts they are required to deliver to the assembly plant. PSA Peugeot-Citroën has set the ambitious objective of ensuring compliance with all list entries upon arrival at the assembly plant. This objective is equivalent to instituting a global first-in, first-out (FIFO) management policy for all operations upstream of the assembly line (i.e. body shop, paint shop) and in particular it enables one to make significant reductions in component inventories. However, FIFO-based flows are difficult to achieve. They first require setting up local production scheduling in the plant in order to satisfy constraints specific to each shop (body shop, paint shop, assembly line); this step will be referred to as 'local scheduling'. Moreover, a number of disturbances intervene to change the initial order. The aim of our work is to lay out a new policy for managing flows (called 'reorderable scheduling'). The premise is to define the maximum scheduling level allowed upon input into each shop so as to guarantee restoration of the initial list order (i.e. reordering) at the assembly entrance. We will start by studying, from a theoretical perspective, a very general base case and then we will characterize the maximum authorized local scheduling disturbance that enables us to fulfill the global management objective (i.e. FIFO). We will also show the implementation of this method in our industrial case within the context of an automotive assembly plant and finally perform the validation step by means of simulation. [ABSTRACT FROM AUTHOR]

Copyright of Contemporary Accounting Research is the property of Canadian Academic Accounting Association and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

This paper reports an investigation of some data and method effects on the predictive accuracy of LIFO/FIFO classification models. The methods compared were probit, ID3, and neural networks. Experiments were conducted to study the effect of data characteristics on classification accuracy and the situations under which a particular method performs better. Hold-out samples were used to calculate the predictive accuracy. The results indicate that (1) different methods identify different factors that affect the LIFO/FIFO choice and (2) in hold-out tests, neural network models have the highest average predictive accuracy, whereas ID3 models have the lowest. Neural network models are the best when dominant nominal variables are present; otherwise, probit models are the best. [ABSTRACT FROM AUTHOR]

The effect of two issuing policies, LIFO and FIFO, on the inventory level in a production lot size model for items with varying rate of deterioration is studied. An implicit form of inventory level under each policy is developed for each phase of a cycle which is shown to be consistent with known extreme cases. A numerical solution procedure employing the Runge-Kutta method and Simpson's Rule is developed to select a preferable policy in terms of the amount deteriorated per unit time. [ABSTRACT FROM AUTHOR]

In a computational experiment, two alternative finite-queue designs are subjected to three full-row operating procedures. For each alternative design certain factors are specified. The effective length of the unit load, the number of unit loads high, the shipment splitting rules and the product set must be included for each product. The actual row length and number of rows also must be detailed for each row type.
Statistical analysis is used to determine whether significant differences exist between alternative finite-queue designs for layouts of equal size. Results of the computational experiment indicate the existence of significant differences between alternative finite-queue designs for layouts of equal size as well as the dominance of the upward product set search full-row operating procedure. Since the experimental results are restricted to the characteristics of a particular set of products, the general result of this work is the development, of a viable computational model and statistical procedures which can be used by a block storage designer.
Certain policy decisions for the storage and retrieval of inventory are assumed. First, unit loads enter and leave the system on a first-in, first-out (FIFO) basis by shipment. Second, different products are not mixed in rows. Third, rows are selected under a space-available system. Fourth, a common queue is provided when entry to the row type is blocked. Fifth, unit loads do not generally have the same dimensions. Sixth, any materials-handling equipment normally used in block storage is acceptable. Seventh, physical constraints are present which limit storage row dimensions. [ABSTRACT FROM AUTHOR]

This paper considers a setting in which managers have private information about the values of their firms and can communicate it to uninformed investors through the use of two signals: capital structure and inventory accounting method. We show conditions under which a separating equilibrium with debt alone does not exist. The two-signal equilibrium involves a partitioned separation in which the highest quality firms choose FIFO and the lower quality firms choose LIFO, and all firms then distinguish themselves within these two partitions through capital structure choices. The analysis helps to explain the many observed empirical regularities about firms' capital structure choices and LIFO/FIFO choices and, in addition, produces numerous testable predictions about the relation between capital structure and inventory accounting method. [ABSTRACT FROM AUTHOR]

The LIFO inventory valuation method has received a great deal of attention as a means of postponing taxes. At the same time the tax consequences of a LIFO inventory liquidation have been virtually ignored. This research indicates that LIFO layer liquidations do occur and can, therefore, cause cash flow problems for corporations in the form of higher federal income tax payments. A hypothesis that LIFO layer liquidations is specific to certain cyclical industries was tested and affirmed. A survey indicated that two factors, cost of capital and income tax expense, were the more critical in the LIFO layer liquidation decision. [ABSTRACT FROM AUTHOR]

The widespread decision of small companies to avoid using LIFO is discussed as a function of the difficulties that companies have in complying with LIFO requirements. 1983 survey estimates indicate that small companies face considerably higher costs in switching to LIFO than do large companies. Both large and small companies could save a large proportion of their LIFO conversion costs if LIFO regulations were modified to permit use of government price indexes in determining price changes. [ABSTRACT FROM AUTHOR]

The article suggests that the adoption of selected U.S. Internal Revenue Service proposals for the use of the last-in, first-out (LIFO) method will cause accounting problems. As an interim solution, the Securities and Exchange Commission will likely provide guidance for publicly held companies or maybe impose a moratorium on switches from LIFO to the first-in, first-out (FIFO) method. The LIFO method looks to the cost flows rather than physical flows of goods by assuming that the most recently received goods are the ones sold. In times of rising prices, LIFO reflects profits available for distribution better than does FIFO because LIFO profits have been charged with costs incurred to replace the inventory while this added cost is not charged in determining FIFO earnings.

This paper presents a stylized game-theoretic model in which inventory accounting choices of firms convey proprietary information to their competitors, and hence those choices are strategically made. The model provides a rationale for the use of FIFO by some firms, foregoing significant amounts of tax benefits which could be captured by the use of LIFO. An explanation is also given for negative market reactions to LIFO adoptions documented by most of the empirical studies of LIFO/FIFO decisions. A further result obtained is that, given a certain condition, the use of FIFO (thus foregoing the LIFO tax benefit) would be more frequently observed in industries with high barriers to entry. Some extensions and limitations of the model are also discussed. [ABSTRACT FROM AUTHOR]

The article comments on the paper by Chi-Wen Jevons Lee about the inventory accounting and earnings/price (E/P) ratios entitled "Inventory Accounting and Earnings/Price Ratios: A Puzzle." The author questions the validity of use of 'ceteris paribus' in Lee's conclusions. The paper compares long-time last in, first out (LIFO) users with non-LIFO firms, or first in, first out (FIFO), and found that LIFO users tend to be larger and more capital intensive with less variable inventories. Companies which adopt LIFO tend to be larger and with less variable inventories and inventory growth. The paper's multivariate model expresses E/P ratios as functions of LIFO and other possible determinants of earnings over price.

The article presents information on the effects of "last in first out" LIFO tax savings on stock price. Although a rise in stock price following announcement of LIFO use is well documented, the size of price increase is not relational with the tax savings. Inflation is the factor that makes utilizing LIFO an advantage and the author investigates the actual change of a firm's tax burden during an inflationary period. The author predicts that inflation will cancel out the tax benefits, making the rise in stock unjustified.

The article focuses on an analysis of the dynamic model of inventory accounting choice. It states that the change in inventory methods correlates with estimations identified of the dynamic model. It comments that an underlying continuous variable can be determined by an econometric threshold model. It states that last-in, first-out (LIFO) adopters revealed more variable rates for inventory growth than first-in, first out (FIFO) users for both postadoption and preadoption periods. It examines a dynamic model of accounting change which assumed changes of accounting states follow first-order Markov processes.

The article focuses on a discussion of the paper "The LIFO/FIFO Choice: An Asymmetric Information Approach," concerning last in, first out (LIFO) and first in, first out (FIFO) choice issues. It states that some firms choose FIFO over LIFO to signal better prospects and high quality, while LIFO has tax and cash-flow benefits. It suggests the demand for signalling behavior could be mitigated with alternative management compensation contracts, and that by increasing the options for potential signaling, FIFO may be less attractive as a signal as FIFO would possess no unique qualities as an effective signal.

The article focuses on the development of model explaining the first-in, first-out (FIFO) and last-in, first-out (LIFO) methods of valuing inventory in firms. It comments on how discretionary accounting change has a direct effect on a corporation's cash flows and possibly on corporate value as well. It mentions that empirical studies reveal a negative market reaction keeping corporations from switching to a LIFO method. It suggests that executives possess private information relevant to a corporation's future prospects and need to select an inventory cost-flow assumption that depends on current and future market prices. It comments that investors will observe LIFO/FIFO choices in deciding how to price a corporation's securities, which in turn influences executives' decision making process.

The article focuses on various systematic properties of companies utilizing last in, first out (LIFO) and first in, first out (FIFO) accounting numbers. It states that tax savings and inventory choice are related, but that the inability to reliably estimate costs and benefits associated with nontax explanations of inventory method choices made it difficult to determine if the data results were more consistent with the tax savings explanation. It suggested that there appeared to be a threshold level of tax savings that would need to be achieved before a company would decide to switch over to LIFO, which is why long-term users of FIFO had not switched to LIFO.

In the past decade, hundreds of firms switched to the LIFO accounting method for their inventories in response to high rates of inflation. Nevertheless, many others continue to use the FIFO method. Biddle [1980] estimated that each of the 105 FIFO firms in his study paid an average of nearly $26 million in additional federal income tax. What makes these FIFO firms so reluctant to switch accounting methods? A review of the literature provides three possible explanations for inventory accounting choices: political costs, agency costs, and divergent production and investment characteristics. Because the required economic variables to test these three alternative explanations are not observable, the empirical tests are based on examination of proxy variables. Many of the proxy variables of the first and third explanations are the same, so it is difficult to discriminate one from the other using univariate statistical methods. For example, there is consistent evidence of an association between size and inventory accounting choices. But size can serve as a proxy for either political costs, or divergent production and investment opportunities, or both. Similarly, there is also strong evidence that the type of industry is associated with inventory choice, which could also be consistent with both explanations. The major purpose of this paper is to test the three: explanations cited above in a simultaneous manner using multivariate probit methods. Probit is a useful statistical technique for discriminating between alternative hypotheses with overlapping proxy variables. For purposes of exposition, we term the third explanation a Ricardian hypothesis. The hypothesis is "Ricardian" in three senses. First, it assumes that all firms are endowed with different production-investment opportunity sets. Second, it assumes that there is perfect intrafirm congruence among the interests of manager, stockholders, and creditors and that there is no economic externality between the... [ABSTRACT FROM AUTHOR]

This study attempted to determine whether the bonuses paid to executives of the firms which switched to LIFO (mostly in 1974) were adversely affected by the switch. The analyses lead to two observations. First, the results indicated that the switch to LIFO did not, on average, adversely affect the income-based performance bonus awards for those executives who elected to make the switch. The switch companies used in this sample apparently adapted their bonus pay to reflect the effect of the LIFO change on income by renegotiating their bonus contracts. Second, the results suggest that executives of the manager-controlled firms that retained FIFO had a relatively higher income-based bonus compared to the other firms. There are several limitations to the study which should be noted. Due to self-selection bias, the results cannot be generalized beyond the sample used here without further replication. Another limitation stems from the method used to measure executives' pay. The variable was measured by the sum of salary, cash bonus; and performance bonus granted in unrestricted stock. Although adding other components of compensation which are typically reported in proxy statements did not materially alter the findings (see Appendix A), the exclusion of stock options and changes in the market values of executives' stock holdings limit the generalizability of these results. Furthermore, bonus payments in any given year might be related to performance in prior years, especially when "total pay" is used. The one-period model used here does not capture these features. Although I do not know how to disentangle these components, a multi-period methodology might be appropriate to address this problem. I find some comfort in the fact that estimation of alternative models did not materially alter the results. [ABSTRACT FROM AUTHOR]

The article discusses last in, first out (LIFO) and first in, first out (FIFO) as they relate to inventory liquidation and negative tax effect. The idea that firms will liquidate inventory to enlarge its after-tax cash flow except when the inventory's costs are higher than historical costs is explored. It was found that firms would use LIFO to liquidate their inventory even though not doing so would have given the companies certain tax incentives. During those years when FIFO liquidations took place, LIFO companies also liquidated their inventory.

The article studies how firms make the decision to be either last in, first out (LIFO) or first in, first out (FIFO), particularly as this relates to inventory-costing decisions. Agency theory is one approach that can explain what things firms consider when making the LIFO/FIFO choice, while the relationship between investors and managers can also be a factor, and related costs and tax effects may also be an influence on the price of goods. The article concludes that tax incentives are a major force behind how firms decide to price their inventory.

The article discusses the additional evidence on the last-in, first-out (LIFO) and FIFO choice using replacement cost data. According to the author the tax savings to the firm adopting LIFO equals the difference between first-in, first-out cost of goods sold (CGS) and LIFO CGS times the firm's marginal tax rate. The distinction of the CGS difference (DIF) for both LIFO and FIFO firms uses an estimation algorithm that used wholesale price indices and assumed a uniform rate of purchases and exclusive use of LIFO or FIFO. The alternative means of estimating CGS DIF uses replacement cost data reported directly by the firms and footnote disclosures of FIFO inventories reported by LIFO firms. The alternative avoids the need to assume a particular pattern of purchases or choose price indices.

The article refers to a study by Biddle concerning inventory costing, managerial decisions, and the last in, first out (LIFO) and first in, first out (FIFO) inventory evaluation methods. Sampling bias in the selection of companies and the two hypotheses that were tested in the Biddle study are discussed. The anticipations hypothesis is where managers anticipate future inventory requirements before making a LIFO or FIFO choice. The incentives hypothesis is where managers are influenced by the tax incentives from LIFO and modify their inventory policy. Tax deferment requires management to maintain year-end inventory levels at the same or greater amount as those at the time that the LIFO method was adopted.

The article refers to a study by Biddle concerning inventory costing and managerial decisions and critiques an association between decisions to adopt the last in, first out (LIFO) and first in, first out (FIFO) accounting methods and year-end inventory levels. Scenarios in the study, which uses an experimental design, show that the anticipation and incentives hypotheses and LIFO tax incentives are based on a model developed by Cohen and Pekelman (1979). The results are uncertain because the model does not consider whether the ending inventory will be sold and covers only one period rather than several which is needed for hypothesis testing.

The article is a reply to comments concerning the author's article about inventory costing and managerial decisions. Two hypotheses are mentioned: the anticipations hypothesis where managers' choices about alternative accounting methods are based on predictions of future costs and benefits associated with each method; and the incentives hypothesis where managers react to the tax-related cash-flow incentives that result from last in, first out (LIFO) and first in, first out (FIFO) alternatives and operating decisions regarding year-end inventory levels. The conclusion is that both hypotheses predict identical associations between LIFO and FIFO decisions and the patterns of year-end inventories.

The article discusses the first-in, first out (FIFO) and last-in, first out (LIFO) accounting methods, inventory costing, tax incentives, and managerial decisions. The mathematical models for determining the dollar-unit measure of year-end inventory levels are based on monthly price indexes and annual price indexes and include FIFO-based cost of goods sold during the specified year. Characteristics of firms that voluntarily change their accounting methods, effects of LIFO-FIFO on cash flow and decision making, capital market efficiency, and stock price reaction to alternative methods are mentioned, as well as research concerning management's motives for changing accounting methods, and the smoothing hypothesis paradigm of management behavior.

The article refers to research on last in, first out (LIFO) and first in, first out (FIFO) inventory costing methods and examines the LIFO cost tradeoffs in a dynamic lot-size inventory model where production and purchase decisions are made. Factors in the planning model--which has the goal of maximizing after-tax profits--include LIFO tax, holding cost, demand forecast, purchase price of inventory, tax rate forecasts, an assumption that there are no stock-outs, and the assumption of a periodic inventory accounting system. Tax savings with the LIFO method during inflationary periods, the welfare perspective in stationary environments, and a nonlinear mathematical program are mentioned.

The article refers to the Warren (1975) study and reports on replicated research concerning the uniformity of auditing standards. The analysis includes two uniformity surrogates--which are the percentages of qualified opinions and different types of opinions to the total number of opinions issued--and nine auditor groupings, as well as three confounding or nuisance variables to control bias. Analysis of variance statistics for the original and replicated studies and data for the interactive effects of variables such as client size, industry, and auditor groupings are discussed. The fiscal year variable, first in, first out and last in, first out inventory methods, effects of recessionary decline, impact of extraordinary items, and Spearman correlation are mentioned.

The article refers to inflation accounting and general price level adjusted (GPLA) accounting and proposes that physical flows--rather than monetary flows--stay constant during periods of inflation. The first in, first out (FIFO) method for inventory evaluation, data from unrestated financial statements, and the calculation of GPLA inventory values and cost of goods sold are discussed. In GPLA, FIFO estimates the monetary flows using aggregate financial data. Functions for restating purchases, ending inventories, initial inventories, and cost of goods sold are explained and compared with GPLA computations. Formulas for restating financial data and evaluating approximation errors are mentioned.

The article refers to research by Jorgenson and Siebert (1968) and Elliott (1973) and examines the effect of accounting methods on the ranking of investment models. Four models of corporate investment behavior are discussed--neoclassical, liquidity, accelerator, and expected profits. Potential for distortion is studied via two inventory methods--first in, first out and last in, first out--and the three depreciation techniques of straight line depreciation, sum-of-years' digits method, and double-declining balance method. Ten firms in ten industries are mentioned, including Anaconda and R.J. Reynolds, as well as data for standard error, Kendall's coefficient of concordance, and a two-way comparison of each model's performance and rank after comparison.

The article examines the question of whether last in, first out versus first in, first out inventory alternatives affected the association between market-determined and accounting-determined risk measures. The study used the Spearman rank correlation model. The author performed the extension with the three independent variables, namely dividend payout, earnings variability and growth. The standard error of estimate is higher. The earnings variability has the bulk of the explanatory power and the t-values for the variable are fairly high. The difference in accounting methods is relevant using the instrumental variable approach for forecasting future market-determined risk measure.

The article presents an examination of two accounting methods for inventory valuation: first-in, first-out and last-in, first-out. The purpose of this study is to present procedures to estimate the difference between the net present value of tax payments under two inventory valuation methods. The assumption of year end inventories is relaxed to acquire the present value of cash-flow differences with changing inventory levels inventory within a framework. In a second extension, the rates of price changes are replaced by a stochastic process to compute the expected value of cash-flow differences. Third, the deterministic inventory level is removed and a stochastic process is implemented in order to compute the expected present value of cash-flow differences for a sequence of price changes.

The article discusses accounting ratio and market risks in term of Last In, First Out (LIFO) versus First In, First Out (FIFO) inventory alternative. The study was conducted in two stages, the first dealing with the issue of whether one should expect LIFO and FIFO methods to affect intercompany comparisons of accounting ratios, and the second being determined by whether the LIFO-FIFO choice influences the intercompany comparability of accounting ratios. The authors make predictions about the association between rankings based on accounting ratios with rankings based on the market beta. Data is used to test the co-relations between accounting ratios and the beta measure using data obtained from Moody's Investors Service Inc.

Copyright of International Journal of Production Research is the property of Taylor & Francis Ltd and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The article looks at the effect of inventory costing methods on full and direct costing in the U.S. The differences in profit under full and direct costing are analyzed in relation to the average cost, first-in, first-out, last-in, first-out, and standard cost methods. Critical factors that determine whether the direct or the full cost method yields greater profits will vary depending on inventory costing methods. The author notes that there is always more pressure to build up inventory under full than under direct costing depending on the level of profits financial managers wish to display. Differences in profit variance patterns between full cost and direct cost methods are analyzed.

Polar code has been proven to achieve the symmetric capacity of memoryless channels. However, the successive cancellation decoding algorithm is inherent serial in nature, which will lead to high latency and low throughput. In order to obtain high throughput, we design a deeply pipelined polar decoder and optimize the processing elements and storage structure. We also propose an improved fixed-point nonuniform quantization scheme, and it is close to the floating-point performance. Two-level control strategy is presented to simplify the controller. In addition, we adopt FIFO structure to implement the α_memory and β_memory and propose the 348-stage pipeline decoder. [ABSTRACT FROM AUTHOR]

The following online problem arises in network devices, e.g., switches, with quality of service (QoS) guarantees. In each time step, an arbitrary number of packets arrive at a single buffer and only one packet can be transmitted. The differentiated service concept is implemented by attributing each packet with a non-negative value corresponding to its service level. The goal is to maximize the total value of transmitted packets. We consider two models of this problem, the FIFO and the bounded-delay model. In the FIFO model, the buffer can store a limited number of packets and the sequence of transmitted packets has to be a subsequence of the arriving packets. In this model, a buffer management algorithm can reject arriving packets and preempt buffered packets. In the bounded-delay model, the buffer has unbounded capacity, but each packet has a deadline and packets can only be transmitted before their deadlines. Here, a buffer management algorithm determines the packet to be sent in each time step. We study comparison-based buffer management algorithms, i.e., algorithms that make their decisions based solely on the relative order between packet values with no regard to the actual values. This kind of algorithm proves to be robust in the realm of QoS switches. Kesselman et al. (SIAM J Comput 33(3):563–583, 2004) present two deterministic comparison-based online algorithms, one for each model, which are 2-competitive. For a long time, it has been an open problem, whether a comparison-based online algorithm exists, in either model, with a competitive ratio below 2. In the FIFO model, we present a lower bound of 1+1/2≈1.707 on the competitive ratio of any deterministic comparison-based algorithm and give an algorithm that matches this lower bound in the case of monotonic sequences, i.e., packets arrive in a non-decreasing order according to their values. In the bounded-delay model, we show that no deterministic comparison-based algorithm exists with a competitive ratio below 2. In the special s-uniform case, where the difference between the arrival time and deadline of any packet equals s, we present a randomized comparison-based algorithm that is 5 / 3-competitive. [ABSTRACT FROM AUTHOR]

We investigate a two-warehouse inventory model for non-instantaneous deteriorating items with partial backlogging and stock-dependent demand under inflationary conditions. Shortages are allowed. The backlogging rate is variable and depends on the waiting time for the next replenishment. This paper seeks to determine an optimal replenishment policy that minimizes the present value of the total cost per unit time. The necessary and sufficient conditions for the existence and uniqueness of the optimal solution are found. The corresponding problems are formulated and solved with particle swarm optimization. Numerical experimentation and post-optimality analysis are conducted. [ABSTRACT FROM AUTHOR]

We model how a judge schedules cases as a multiarmed bandit problem. The model indicates that a first-in-first-out (FIFO) scheduling policy is optimal when the case completion hazard rate function is monotonic. But there are two ways to implement FIFO in this context: at the hearing level or at the case level. Our model indicates that the former policy, prioritizing the oldest hearing, is optimal when the case completion hazard rate function decreases, and the latter policy, prioritizing the oldest case, is optimal when the case completion hazard rate function increases. This result convinced six judges of the Roman Labor Court of Appeals-a court that exhibits increasing hazard rates-to switch from hearing-level FIFO to case-level FIFO. Tracking these judges for eight years, we estimate that our intervention decreased the average case duration by 12% and the probability of a decision being appealed to the Italian supreme court by 3.8%, relative to a 44-judge control sample. [ABSTRACT FROM AUTHOR]

We theoretically and experimentally study the differential incentive effects of three well known queue disciplines in a strategic environment in which a bottleneck facility opens and impatient players decide when to arrive. For a class of three-player games, we derive equilibrium arrivals under the first-in-first-out (FIFO), last-in-first-out (LIFO), and service-in-random-order (SIRO) queue disciplines and compare these predictions to outcomes from a laboratory experiment. In line with our theoretical predictions, we find that people arrive with greater dispersion when participating under the LIFO discipline, whereas they tend to arrive immediately under FIFO and SIRO. As a consequence, shorter waiting times are obtained under LIFO as compared to FIFO and SIRO. However, while our theoretical predictions admit higher welfare under LIFO, this is not recovered experimentally as the queue disciplines provide similar welfare outcomes. [ABSTRACT FROM AUTHOR]

Background Although recent randomized controlled trials have not found increased risk of morbidity/mortality with older red blood cells ( RBCs), several large trials will be completed soon providing power to detect smaller risks if indeed they exist. Hence, there may still be a need for inventory management policies that could reduce the age of transfused RBCs without compromising availability or resulting in excessive outdates. Materials and Methods We developed a computer simulation model based on data from an acute care hospital in Hamilton, Ontario. We evaluated and compared the performance of certain practical ordering and allocation policies in terms of outdate rate, shortage rate and the distribution of the age of issued RBCs. Results During the 1-year period for which we analysed the data, 10349 RBC units were transfused with an average issue age of 20·7 days and six units were outdated (outdate rate: 0·06%). Adopting a strict first in, first out ( FIFO) allocation policy and an order-up-to ordering policy with target levels set to five times the estimated daily demand for each blood type, reduced the average issue age by 29·4% (to 14·6 days), without an increase in the outdate rate (0·05%) or resulting in any unmet demand. Further reduction of issue age without a significant increase in outdate rate was observed when adopting non- FIFO threshold-based allocation policies and appropriately adjusting the order-up-to levels. Conclusion A significant reduction of issue age could be possible, without compromising availability or resulting in excessive outdates, by properly adjusting the ordering and allocation policies at the hospital level. [ABSTRACT FROM AUTHOR]

This paper presents a case study on operating room scheduling in a small hospital in Chile. Patient flow was represented using a discrete-event simulation model that considered the randomness associated with the primary activities of the entire process, which includes pre- and posthospitalisation, surgery, surgery setup and recovery. A simulated annealing algorithm was implemented and connected to the simulation model to search for better patient schedules. Additionally, three dispatching rules, Shortest Processing Time (SPT), Longest Processing Time (LPT) and First-In, First-Out (FIFO) were used. The results showed that the simulated annealing approach, based on the Cmax objective function, obtained schedules that were 18 % better than the hospital's scheduling practices. The utilisation of dispatching rules also has a significant effect in the Cmax indicator. The SPT rule performed better than the hospital schedule in two of the three experiments considered in the study. [ABSTRACT FROM AUTHOR]