In the warehouse of a large cosmetics company, a mechanized order picker is restocked from nearby shelving, and the shelving is restocked from bulk storage, forming a three-tier inventory system. We consider such multi-tier inventory systems and determine the storage areas to which to assign items, and the quantities in which to store them, in order to minimize the total cost of picking items and restocking storage locations. With this research, we increase the number of inventory systems for which simple search algorithms find a provably near-optimal solution. The model and method were tested on data from the Avon Products distribution center outside Atlanta; the solution identified by the model reduced picking and restocking costs there by 20%. The sales forecasts of items stored in the warehouse may change, however, and new items will be introduced into the inventory system and others removed. To account for these changes, some warehouses may periodically reassign items to storage areas and recompute their storage quantities. These reassignment activities account for additional costs in the warehouse. The second focus of this research examines these costs over several time periods in a simple multi-tier inventory system. We develop heuristics to determine the storage areas to which to assign items and the quantities in which to store them in each time period, in order to minimize the total cost of picking items, restocking storage locations, and reassigning skus over multiple periods.

Cost-effectiveness analysis is widely conducted in the economic evaluation of new treatment options. In many clinical and observational studies of costs, data are often censored. Censoring brings challenges to both medical cost estimation and cost-effectiveness analysis. Although methods have been proposed for estimating the mean costs with censored data, they are often derived from theory and it is not always easy to understand how these methods work. We provide an alternative method for estimating the mean cost more efficiently based on a replace-from-the-right algorithm, and show that this estimator is equivalent to an existing estimator based on the inverse probability weighting principle and semiparametric efficiency theory. Therefore, we provide an intuitive explanation to a theoretically derived mean cost estimator. In many applications, it is also important to estimate the survival function of costs. We propose a generalized redistribute-to-the right algorithm for estimating the survival function of costs with censored data, and show that it is equivalent to a simple weighted survival estimator of costs based on inverse probability weighting techniques. Motivated by this redistribute-to-the-right principle, we also develop a more efficient survival estimator for costs, which has the desirable property of being monotone, and more efficient, although not always consistent. We conduct simulation to compare our method with some existing survival estimators for costs, and find the bias seems quite small. Thus, it may be considered as a candidate for survival estimator for costs in a real setting when the censoring is heavy and cost history information is available. Finally, we consider one special situation in conducting cost-effectiveness analysis, when the terminating events for survival time and costs are different. Traditional methods for statistical inference cannot deal with such data. We propose a new method for deriving the confidence interval for the incremental cost-effectiveness ratio under this situation, based on counting process and the general theory for missing data process. The simulation studies show that our method performs very well for some practical settings. Our proposed method has a great potential of being applied to a real setting when different terminating events exist for survival time and costs.

The purpose of this study was to compare the cost-effectiveness between the 2 types of general anesthesia, namely, laryngeal mask (LMA) and endotracheal intubation (ETT). The study included 353 patients who received general anesthesia during operation in a medical center in Kaohsiung City. Of these, 183 patients were assigned to the LMA group, while the remaining 170 were assigned to the ETT group. The norm of cost adopted by this study was calculated as the average expense per hour incurred by using the anesthetic and hygienic materials for medicinal use. The indices of effectiveness were physical reactions that were tracked at 2 h and 8¡V10 h postoperatively; these indices were acute pain, dizzyness, sore throat, nausea, and vomiting. These 5 indices were rated on a scale of 0¡V10. A low score was considered to represent lesser side-effects and greater effectiveness of the anesthetic. Besides, the shorter the recovery time of the patient was, the higher the effectiveness would be. The conclusion showed that the cost of the average expense per hour produced by the anesthesia and hygienic materials of medicinal use in the LMA group was 531 dollars while in the ETT group was 1,017 dollars. In the LMA group, at 2 h postoperatively, the mean tracking score for acute pain was 2.9 ¡Ó 2.6; for dizzyness, 1.4 ¡Ó 1.9; for sore throat, 0.4 ¡Ó 1.1; for nausea, 0.5 ¡Ó 1.4; and for vomiting, 0.2 ¡Ó 0.9. In the LMA group, at 8¡V10 h postoperatively, the mean tracking score for acute pain was 0.9 ¡Ó 1.5; for dizzyness, 0.6¡Ó1.3; for sore throat, 0.2 ¡Ó 0.7; for nausea, 0.1 ¡Ó 0.6; and for vomiting, 0.07 ¡Ó 0.4. In the ETT group, at 2 h postoperatively, the mean tracking score for acute pain was 4.9 ¡Ó 3.2; for dizzyness, 2.6 ¡Ó 2.5; for sore throat, 2.0 ¡Ó 2.1; for nausea, 1.3 ¡Ó 2.4; and for vomiting, 0.7 ¡Ó 1.9. In the ETT group, at 8¡V10 h postoperatively, the mean tracking score for acute pain was 2.82¡Ó 2.5; for dizzyness, 1.9 ¡Ó 1.9; for sore throat, 1.3 ¡Ó 1.9; for nausea, 1.1 ¡Ó 2.1; and for vomiting, 0.7 ¡Ó 1.9. The mean postoperative recovery time of the patients in the LMA group was 11.5¡Ó13.2 min and that for the patients in the ETT group was 25.9¡Ó16.0 min. T-test was performed to examine the hypothesis that LMA is more cost-effective than ETT when the same variables as those mentioned above are used; the results of all variables support the hypothesis that the p-value of every index was .000. Results of stepwise regression showed that LMA plays a significant positive role in every cost-effectiveness index.

This research provides an example delay calculation for long-haul single unit and combination trucks on Interstate-75 (I-75) in Georgia. Truck profiles on Georgia interstates are used to calculate the value of freight by truck type and commodity moved. Determining the types of trucks and commodities moved within the state of Georgia allows the researcher to monetize the effect of recurring congestion by location in addition to the cost of lost time. A more accurate calculation of delay based on truck type and commodity moved will better inform the Georgia Department of Transportation about the performance of Georgia's major truck routes and its potential effect on the local economy. A review of past research on this topic found that the calculated cost of delay in previous studies varied widely based on truck and commodity type. The identification of the types of commodities moved can assist in better monetizing the value of truck freight. Using forecast data on future truck traffic volume increases in the corridor, the growing importance of putting a value on different types of truck freight delay costs are demonstrated.

<p>In electricity markets evolving towards liberalisation and internationalisation, green certificates are seen as an important tool to promote production of renewable energy. In a green certificate market producers sell certificates received per unit of electricity generated from renewable energy. Trade in renewability is thereby decoupled from the the physical electricity trade. Tradable green certificates in combination with renewables obligation are implemented or planned in several EU member states. Integration at EU leveland the creation of a common certificate market seem like a possible next step. Using a simple model, the effects of an EU system for tradable green certificates, compared to national implementation, are tested for the period 2000–2010. The simulations show a clear increase of cost effectiveness and large changes in the geographical balance of renewable energy when reaching the EU 22 per cent target. Less competitive technologies, such as solar power, are not deployed at all. The situation is however similar without international trade. Rather than implementing a certificate market with all EU member states, but with different support schemes, a smaller market, only with countries that combine the certificate market with renewables obligation, is recommended.</p>

<p>The purpose of this thesis is to develop a model for assessing cost effectiveness of applying lean tools. The</p><p>model consists of eight phases: it starts by understanding customers' requirements using Voice of Customer</p><p>(VOC) and Quality Function Deployment (QFD) tools. In phase 2, the current state of plant is assessed</p><p>using lean profile charts based on Balanced Scorecard (BSC) measures. In phase 3 and phase 4,</p><p>identification of critical problem(s) and generating of improvement suggestion(s) are performed. Phase 5</p><p>provide evaluation of the cost effectiveness of implementing the suggested lean methods based on life cycle</p><p>cost analysis (LCCA) and phase 6 prefers the right alternative based on multiple criteria decision making</p><p>(MCDM). In phase 7 the selected alternative is supposed to be implemented and finally the user should</p><p>monitor and control the process to make sure that the improvement is going as planned. The model was</p><p>verified successfully using a case study methodology at one Swedish sawmill called Södra Timber in</p><p>Ramkvilla, one part of Södra group. Results obtained from the study showed that the production and human</p><p>resources perspectives are the most critical problem areas that need to be improved. They got the lowest</p><p>scores in the lean profile, 63% and 68%, respectively. Using value stream mapping (VSM) it was found that</p><p>the non value added (NVA) ratios for the core and side products are 87.4% and 90.4%, respectively. Using</p><p>the model, three improvement alternatives were suggested and evaluated using LCCA and MCDM.</p><p>Consequently, implementing 5S got the highest score, second came redesigning the facility layout.</p><p>However, it was estimated that 4.7 % of NVA for the side product would be reduced by redesigning the</p><p>facility layout. The recommendations were suggested for the company to improve their performance. The</p><p>novelty of the thesis is based on the fact that it addresses two main issues related to lean manufacturing:</p><p>firstly, suggesting lean techniques based on assessment of lean profile that is based on BSC and QFD, and</p><p>secondly assessing the cost effectiveness of the suggested lean methods based on LCCA and MCDM. This</p><p>thesis provides a generalized model that enables the decision-maker to know and measure, holistically, the</p><p>company performance with respect to customer requirements. This will enable the company to analyze the</p><p>critical problems, suggest solutions, evaluate them and make a cost effective decision. Thus, the company</p><p>can improve its competitiveness.</p>

<p>To stay competitive, companies are forced to improve their products continuously. Field data is a source of information that shows the actual performance of products during operation, and that information can be used to clarify the items in need of improvements. This master thesis aims at identifying the set of field data that is required for dependability improvements and to develop a working procedure that enables increased utilization of the field data in order to make cost-effective design improvements. To achieve this, a 12-step model called the Design Improvement Cycle (DIC) was developed and tested in a single case study. The field data need was identified using a top-down method and was included as a part of the DIC.</p><p>Testing of the model showed that it was practicable and each step could be carried through, even though the last steps only could be tested hypothetically during discussions with concerned personnel. The model implied a working procedure that should be aimed at, according to personnel with competence within the subject. As the DIC appeared to be very flexible it should be possible to use within several areas. It was discovered that field data was not a sufficient source of information to support design improvements but it could be used to indicate which items that should be focused on during further investigations. The quality of the field data had a big impact on the analysis possibilities and to point out which data quality issues that had to be amended to make the data more useful, the data need for dependability improvements could be used.</p>

Thesis (M.B.A.)--Naval Postgraduate School, December 2003. / "MBA professional report"--Cover. Joint authors: Robert K. DeGuzman Jr., Thomas S. Fulford III, Jesse E. Porter Sr. Thesis advisor(s): Donald R. Eaton, Kevin R. Gue, Mary A. Malina. Includes bibliographical references (p. 71-73). Also available online.

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Lack of affordable feeds is one of the major constraints facing small-scale fish farmers in Tanzania. This study evaluated the suitability of moringa leaf meal (MLM), cassava leaf meal (CLM) and cassava root meal (CRM) as novel ingredients in Nile tilapia, Oreochromis niloticus diets. Each of the ingredients was processed in an attempt to remove the most significant antinutritional factor. A series of five experiments was conducted in a recirculation system using juvenile O. niloticus. The fish were fed isonitrogenous (30g 100g-1), isolipidic (10g 100g-1) and isoenergetic (18 kJ g-1) diets containing graded levels of the processed ingredients to their apparent appetite but not exceeding 10% of their body weight for a period of 8 weeks. Processing led to the removal of 0.3% of saponin from MLM and 60% and 90% of hydrogen cyanide from CLM and CRM respectively. The contents of other inherent antinutritional factors such as phenols, tannins and phytic acid were little affected. Processed MLM, CLM and CRM had 31.1/29.0/1.5g 100g-1 of crude protein, 5.9/10.2/2.4g 100g-1 of crude fibre and 20.1/19.7/15.8k Jg-1 of gross energy. The content of sulphur amino acids was higher in CLM (0.47%) than in MLM (0.23%). Digestibe protein and digestible energy was higher in MLM (25.71g 100g-1/15.44kJ g-1) than in CLM (12.71g 100-1/9.16kJ g-1). CRM had a digestible energy content of 13.5kJ g-1. Inclusion of either of the leaf meals, even at the lowest level of 15g 100g-1 of total dietary protein, led to a significant reduction in feed intake, growth and feed utilisation. Liver and small intestine did not show any histopathological changes which could be linked to dietary treatment. Conversely, cassava root meal could replace up to 75% of wheat meal in the diet without significantly affecting performance. The performance of leaf meals was marginally improved by a combination of blending and feeding stimulants, whereby a blend containing 1 part MLM and 2 parts CLM could provide up to 20g 100g-1 of dietary protein without significantly reducing performance. Biological and economic performance of practical diets containing 30-50g 100g-1 of dietary protein from moringa and cassava blends (LMB) with feeding stimulants was significantly lower than a fishmeal-meal based diet (FM) but comparable to a soybean meal-based diet (SBM). The suitability of MLM and CLM as novel protein sources in O. niloticus diets will depend on 1) improving reduction/removal of inherent antinutritional factors in MLM and CLM as well as improving digestibility of CLM. On the other hand, the suitability of CRM as a carbohydrate energy source will depend on the availability of cost effective protein sources due to its low protein content.