Development of a Decision Support Tool for the Process of Deciding Inventory Levels : A Study at The Absolut Company

Background: Supply Chain Management is receiving increased attention as companies are trying to remain competitive in a global and challenging environment. An important topic to consider when managing the supply chain is inventory control. Companies today have enormous investments in inventories, which means that there are potential improvements regarding tied up capital in raw materials, work-in-progress and finished goods. There are a variety of tools available in the theory to support the process of determining inventory levels, but these general tools are not suitable for every company. Problem description: This master thesis was conducted at The Absolut Company (TAC) – a large spirits manufacturer. They are responsible for the production of Absolut Vodka, a premium vodka brand. As for any manufacturing company it is crucial that the production constantly has material available to avoid stoppages in the lines. The inventory of the bottle cap, which is one of the materials used in the production process, has historically been kept high to ensure constant supply, but now TAC has started to question if these is managed correctly. Hence, there is a desire from TAC to develop a better understanding of what is affecting the inventory levels. There is also a need for an analytical tool that supports the decision making process related to the inventory levels of the bottle caps. Purpose:The purpose of this master thesis is to investigate which factors affect the inventory levels of bottle caps at TAC and to develop a decision support tool for the process of determining appropriate inventory levels for the bottle caps. Research questions: 1. What factors are affecting the inventory levels at TAC? 2. How do the identified factors affect the inventory levels of bottle caps at TAC? 3. How should a tool for deciding appropriate inventory levels of the bottle caps at TAC be designed? Methodology: The research approach for this thesis is a systems approach and the research is performed inductively. A case study has been chosen as research strategy and the design of the case is single case and single unit of analysis. The system is studied by analyzing both qualitative (interview and observations) and quantitative data (operational data from TAC’s ERP system). The quality of the research is evaluated based on the dimensions reliability and validity. Conclusion: During the analysis it was concluded that the factors affecting the inventory levels at TAC come from the cycle and safety inventory. The identified factors associated with the cycle inventory were supplier lead time, purchase batching and production batching, while the factors affecting the safety inventory were forecast accuracy, quality defects, delivery reliability and delivery dependability. From the analysis it was concluded that the factors purchase batching, forecast error and delivery reliability contributed the most to the inventory levels at TAC. The decision support tool was designed to suggest appropriate inventory levels and to give the user an overview of how much each factor contributes to the inventory. In the tool a baseline scenario, reflecting the current situation, and two alternative scenarios are presented. One scenario shows appropriate inventory levels to cover for the mean error and the other scenario is calculated to cover for the maximum error. The tool also gives the user an overview of all the factors affecting the inventory levels of caps that can be used to spread the information in the company and create understanding across departments. Furthermore, the decision support tool can be used to analyze how improvements or deteriorations of the factors affect the inventory levels, to support TAC’s supply chain department in deciding which improvement project should be prioritized

Disordered, strongly scattering porous materials as miniature multipass gas cells

Spectroscopic gas sensing is both a commercial success and a rapidly advancing scientific field. Throughout the years, massive efforts have been directed towards improving detection limits by achieving long interaction pathlengths. Prominent examples include the use of conventional multipass gas cells, sophisticated high-finesse cavities, gas-filled holey fibers, integrating spheres, and diffusive reflectors. Despite this rich flora of approaches, there is a continuous struggle to reduce size, gas volume, cost and alignment complexity. Here, we show that extreme light scattering in porous materials can be used to realise miniature gas cells. Near-infrared transmission through a 7 mm zirconia (ZrO2) sample with a 49% porosity and subwavelength pore structure (on the order of 100 nm) gives rise to an effective gas interaction pathlength above 5 meters, an enhancement corresponding to 750 passes through a conventional multipass cell. This essentially different approach to pathlength enhancement opens a new route to compact, alignment-free and low-cost optical sensor systems

Transport in quenched disorder: light diffusion in strongly heterogeneous turbid media

We present a theoretical and experimental study of light transport in disordered media with strongly heterogeneous distribution of scatterers formed via non-scattering regions. Step correlations induced by quenched disorder are found to prevent diffusivity from diverging with increasing heterogeneity scale, contrary to expectations from annealed models. Spectral diffusivity is measured for a porous ceramic where nanopores act as scatterers and macropores render their distribution heterogeneous. Results agree well with Monte Carlo simulations and a proposed analytical model.Comment: 12 pages, 9 figures (significant amount of supplemental information

Nanostructured micro particles as a low-cost and sustainable catalyst in the recycling of PET fiber waste by the glycolysis method

Magnetic Mg-Al-O@Fe3O4 micro particles were synthesized by coating nanosized Mg-Al double oxidesonto Fe3O4 micro particles. The formed hierarchical structure gave Mg-Al-O@Fe3O4 micro particles a highactive surface area, which enabled these micro particles to work efficiently as a catalyst in the glycolysisof poly(ethylene terephthalate) (PET). The bis(hydroxyethyl) terephthalate (BHET) yield reached above80 mol% in the presence of 0.5 wt% of Mg-Al-O@Fe3O4 micro catalyst in the reaction system within90 min at 240 C. After the reaction, Mg-Al-O@Fe3O4 micro catalyst was easily retrieved by a magneticdecantation and can be repetitively used for two times with a high catalytic efficiency. After that, thedeactivated Mg-Al-O@Fe3O4 micro catalyst can be regenerated by heat treatment. The regenerated Mg-Al-O@Fe3O4 micro catalyst displays a comparable catalytic performance as that of the virgin catalyst.In addition, the Mg-Al double oxides and Fe3O4 micro particles are low-cost and environmentally benign.Therefore, the Mg-Al-O@Fe3O4 micro catalyst may contribute to an economically and environmentallyimproved large-scale circular recycling of PET fiber waste

Wall-collision line broadening of molecular oxygen within nanoporous materials

Wall-collision broadening of near-infrared absorption lines of molecular oxygen confined in nanoporous zirconia is studied by employing high-resolution diode-laser spectroscopy. The broadening is studied for pores of different sizes under a range of pressures, providing new insights on how wall collisions and intermolecular collisions influence the total spectroscopic line profile. The pressure series show that wall-collision broadening is relatively more prominent under reduced pressures, enabling sensitive means to probe pore sizes of porous materials. In addition, we show that the total wall-collision-broadened profile strongly deviates from a Voigt profile and that wall-collision broadening exhibits an additive-like behavior to the pressure and Doppler broadening

Long-term stability of an injection-molded zirconia bone-level implant: A testing protocol considering aging kinetics and dynamic fatigue

Abstract Objective Separately addressing the fatigue resistance (ISO 14801, evaluation of final product) and aging behavior (ISO 13356, standardized sample) of oral implants made from yttria-stabilized zirconia proved to be insufficient in verifying their long-term stability, since (1) implant processing is known to significantly influence transformation kinetics and (2) aging, up from a certain level, is liable to decrease fatigue resistance. Therefore, the aim of this investigation was to apply a new testing protocol considering environmental conditions adequately inducing aging during dynamic fatigue. Methods Zirconia implants were dynamically loaded (107 cycles), hydrothermally aged (85\ub0, 60 days) or subjected to both treatments simultaneously. Subsequent, monoclinic intensity ratios (Xm) were obtained by locally resolved X-ray microdiffraction (\u3bc-XRD2). Transformation propagation was monitored at cross-sections by \u3bc-Raman spectroscopy and scanning electron microscopy (SEM). Finally, implants were statically loaded to fracture. Linear regression models (fracture load) and mixed models (Xm) were used for statistical analyses. Results All treatments resulted in increased fracture load (p 64 0.005), indicating the formation of transformation induced compressive stresses around surface defects during all treatment modalities. However, only hydrothermal and combinational treatment were found to increase Xm (p < 0.001). No change in Xm was observed for solely dynamically loaded samples (p 65 0.524). Depending on the variable observed, a monoclinic layer thickness of 1\u20132 \u3bcm (SEM) or 6\u20138 \u3bcm (Raman spectroscopy) was measured at surfaces exposed to water during treatments. Significance Hydrothermal aging was successfully induced during dynamic fatigue. Therefore, the presented setup might serve as reference protocol for ensuring pre-clinically long-term reliability of zirconia oral implants

Towards long lasting zirconia-based composites for dental implants: Transformation induced plasticity and its consequence on ceramic reliability

Zirconia-based composites were developed through an innovative processing route able to tune compositional and microstructural features very precisely. Fully-dense ceria-stabilized zirconia ceramics (84 vol% Ce-TZP) containing equiaxed alumina (8 vol%Al2O3) and elongated strontium hexa-aluminate (8 vol% SrAl12O19) second phases were obtained by conventional sintering. This work deals with the effect of the zirconia stabilization degree (CeO2 in the range 10.0\u201311.5 mol%) on the transformability and mechanical properties of Ce-TZP-Al2O3-SrAl12O19 materials. Vickers hardness, biaxial flexural strength and Single-edge V-notched beam tests revealed a strong influence of ceria content on the mechanical properties. Composites with 11.0 mol% CeO2 or above exhibited the classical behaviour of brittle ceramics, with no apparent plasticity and very low strain to failure. On the contrary, composites with 10.5 mol% CeO2 or less showed large transformation-induced plasticity and almost no dispersion in strength data. Materials with 10.5 mol% of ceria showed the highest values in terms of biaxial bending strength (up to 1.1 GPa) and fracture toughness (>10 MPa 1am). In these ceramics, as zirconia transformation precedes failure, the Weibull modulus was exceptionally high and reached a value of 60, which is in the range typically reported for metals. The results achieved demonstrate the high potential of using these new strong, tough and stable zirconia-based composites in structural biomedical applications

Characterisation of age and polarity at onset in bipolar disorder

Background Studying phenotypic and genetic characteristics of age at onset (AAO) and polarity at onset (PAO) in bipolar disorder can provide new insights into disease pathology and facilitate the development of screening tools. Aims To examine the genetic architecture of AAO and PAO and their association with bipolar disorder disease characteristics. Method Genome-wide association studies (GWASs) and polygenic score (PGS) analyses of AAO (n = 12 977) and PAO (n = 6773) were conducted in patients with bipolar disorder from 34 cohorts and a replication sample (n = 2237). The association of onset with disease characteristics was investigated in two of these cohorts. Results Earlier AAO was associated with a higher probability of psychotic symptoms, suicidality, lower educational attainment, not living together and fewer episodes. Depressive onset correlated with suicidality and manic onset correlated with delusions and manic episodes. Systematic differences in AAO between cohorts and continents of origin were observed. This was also reflected in single-nucleotide variant-based heritability estimates, with higher heritabilities for stricter onset definitions. Increased PGS for autism spectrum disorder (β = −0.34 years, s.e. = 0.08), major depression (β = −0.34 years, s.e. = 0.08), schizophrenia (β = −0.39 years, s.e. = 0.08), and educational attainment (β = −0.31 years, s.e. = 0.08) were associated with an earlier AAO. The AAO GWAS identified one significant locus, but this finding did not replicate. Neither GWAS nor PGS analyses yielded significant associations with PAO. Conclusions AAO and PAO are associated with indicators of bipolar disorder severity. Individuals with an earlier onset show an increased polygenic liability for a broad spectrum of psychiatric traits. Systematic differences in AAO across cohorts, continents and phenotype definitions introduce significant heterogeneity, affecting analyses