3,948 research outputs found

    The impact of macroeconomic leading indicators on inventory management

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    Forecasting tactical sales is important for long term decisions such as procurement and informing lower level inventory management decisions. Macroeconomic indicators have been shown to improve the forecast accuracy at tactical level, as these indicators can provide early warnings of changing markets while at the same time tactical sales are sufficiently aggregated to facilitate the identification of useful leading indicators. Past research has shown that we can achieve significant gains by incorporating such information. However, at lower levels, that inventory decisions are taken, this is often not feasible due to the level of noise in the data. To take advantage of macroeconomic leading indicators at this level we need to translate the tactical forecasts into operational level ones. In this research we investigate how to best assimilate top level forecasts that incorporate such exogenous information with bottom level (at Stock Keeping Unit level) extrapolative forecasts. The aim is to demonstrate whether incorporating these variables has a positive impact on bottom level planning and eventually inventory levels. We construct appropriate hierarchies of sales and use that structure to reconcile the forecasts, and in turn the different available information, across levels. We are interested both at the point forecast and the prediction intervals, as the latter inform safety stock decisions. Therefore the contribution of this research is twofold. We investigate the usefulness of macroeconomic leading indicators for SKU level forecasts and alternative ways to estimate the variance of hierarchically reconciled forecasts. We provide evidence using a real case study

    Aggregating Prophet and Seasonal Trend Decomposition for Time Series Forecasting of Italian Electricity Spot Prices

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    The cost of electricity and gas has a direct influence on the everyday routines of people who rely on these resources to keep their businesses running. However, the value of electricity is strongly related to spot market prices, and the arrival of winter and increased energy use owing to the demand for heating can lead to an increase in energy prices. Approaches to forecasting energy costs have been used in recent years; however, existing models are not yet robust enough due to competition, seasonal changes, and other variables. More effective modeling and forecasting approaches are required to assist investors in planning their bidding strategies and regulators in ensuring the security and stability of energy markets. In the literature, there is considerable interest in building better pricing modeling and forecasting frameworks to meet these difficulties. In this context, this work proposes combining seasonal and trend decomposition utilizing LOESS (locally estimated scatterplot smoothing) and Facebook Prophet methodologies to perform a more accurate and resilient time series analysis of Italian electricity spot prices. This can assist in enhancing projections and better understanding the variables driving the data, while also including additional information such as holidays and special events. The combination of approaches improves forecast accuracy while lowering the mean absolute percentage error (MAPE) performance metric by 18% compared to the baseline model

    Forecasting Nigeria\u27s Electricity Demand and Energy Efficiency Potential Under Climate Uncertainty

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    The increasing population and socio-economic growth of Nigeria, coupled with the current, unmet electricity demand, requires the need for power supply facilities expansion. Of all Nigeria’s electricity consumption by sector, the residential sector is the largest and growing at a very fast rate. To meet this growing demand, an accurate estimation of the demand into the future that will guide policy makers to adequately plan for the expansion of electricity supply and distribution, and energy efficiency standards and labeling must be made. To achieve this, a residential electricity demand forecast model that can correctly predict future demand and guide the construction of power plants including cost optimization of building these power infrastructures is needed. Modelling electricity demand in developing countries is problematic because of scarcity of data and methodologies that adequately consider detailed disaggregation of household appliances, energy efficiency improvements, and stock uptakes. This dissertation addresses these gaps and presents methodologies that can carry out a detailed disaggregation of household appliances, a more accurate electricity demand projection, peak load reduction, energy savings, economic, and environmental benefits of energy efficiency in the residential sector of Nigeria. This study adopts a bottom-up and top-down approach (hybrid) supplemented with hourly end-use demand profile to model residential electricity consumption. and project efficiency improvement through the introduction of energy efficiency standards and labelling (EE S&L) under two scenarios (Business As Usual and Best Available Technology). A consumer life-cycle cost analysis was also conducted to determine the cost-effectiveness of introducing EE S& L to consumers. The results show significant savings in energy and carbon emissions, increased cooling demand due to climate uncertainty, and negative return on investment and increase lifecycle costs to consumers who purchase more efficient appliances. These results are subject to some level of uncertainties that are mainly caused by the input data. The uncertainties were analyzed based on a Monte Carlo Simulation. The uncertainties that were considered including the type of distributions applied to them were outlined and the result of the outputs were presented

    Uncertainty Quantification And Economic Dispatch Models For The Power Grid

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    The modern power grid is constrained by several challenges, such as increased penetration of Distributed Energy Resources (DER), rising demand for Electric Vehicle (EV) integration, and the need to schedule resources in real-time accurately. To address the above challenges, this dissertation offers solutions through data-driven forecasting models, topology-aware economic dispatch models, and efficient optional power flow calculations for large scale grids. Particularly, in chapter 2, a novel microgrid decomposition scheme is proposed to divide the large scale power grids into smaller microgrids. Here, a two-stage Nearest-Generator Girvan-Newman (NGGN) algorithm, a graphicalclustering-based approach, followed by a distributed economic dispatch model, is deployed to yield a 12.64% cost savings. In chapter 3, a deep-learning-based scheduling scheme is intended for the EVs in a household community that uses forecasted demand, consumer preferences and Time-of-use (TOU) pricing scheme to reduce electricity costs for the consumers and peak shaving for the utilities. In chapter 4, a hybrid machine learning model using GLM with other methods was designed to forecast wind generation data. Finally, in chapter 5, multiple formulations for Alternating Current Optimal Power Flow (ACOPF) were designed for large scale grids in a high-performance computing environment. The ACOPF formulations, namely, power balance polar, power balance Cartesian, and current balance Cartesian, are tested on bus systems ranging from a 9-bus to 25,000. The current balance Cartesian formulation had an average of 23% faster computational time than two other formulations on a 25,000 bus system

    Forecasting: theory and practice

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    Forecasting has always been in the forefront of decision making and planning. The uncertainty that surrounds the future is both exciting and challenging, with individuals and organisations seeking to minimise risks and maximise utilities. The lack of a free-lunch theorem implies the need for a diverse set of forecasting methods to tackle an array of applications. This unique article provides a non-systematic review of the theory and the practice of forecasting. We offer a wide range of theoretical, state-of-the-art models, methods, principles, and approaches to prepare, produce, organise, and evaluate forecasts. We then demonstrate how such theoretical concepts are applied in a variety of real-life contexts, including operations, economics, finance, energy, environment, and social good. We do not claim that this review is an exhaustive list of methods and applications. The list was compiled based on the expertise and interests of the authors. However, we wish that our encyclopedic presentation will offer a point of reference for the rich work that has been undertaken over the last decades, with some key insights for the future of the forecasting theory and practice

    Iberian Energy Market: Spot Price Forecast by Modelling Market Offers

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    Electricity is a very special commodity since it is economically non-storable, and thus requiring a constant balance between production and consumption. At the corporate level, electricity price forecasts have become a fundamental input to energy companies’ decision making mechanisms [22, 45]. Electric utilities are higly vulnerable to economical crisis, since they generally cannot pass their excess costs on the wholesale market to the retail consumers [77] and, since the price depends on variables like weather (temperature, wind speed, precipitation, etc.) and the intensity of business and everyday activities (on-peak vs. off-peak hours, weekdays vs. weekends, holidays and near-holidays, etc.) it shows specific dynamics not observed in any other market, exhibiting seasonality at the daily, weekly and annual levels, and abrupt, short-lived and generally unanticipated price spikes. These extreme price volatility make price forecasts from a few hours to a few months ahead to become of particular interest to power portfolio managers. An utility company or large industrial consumer who is able to accurately forecast the wholesale prices and it’s volatility, can adjust its bidding strategy and its own production/consumption schedule in order to reduce the risk or maximize the profits in day-ahead trading. In this work I discuss the dynamics of the Iberian electricity day-ahead market (OMIE), review the state-of-the-art forecasting techniques and introduce a new approach to Electricity Price Forecasting, by forecasting the underlying dynamics, the market demand/supply curves. With this method it is possible to predict not only the electricity prices for the next hours, but also the market curves, which can then be used for risk management and a more accurate schedule of generation units. I analyze the model results and benchmark them against other models in the industry.A eletricidade é uma commodity muito especial, uma vez que não é possível armazená-la, e por isso, requer um constante equilíbrio entre a produção e consumo. ao nível empresarial, a previsão de preços de eletricidade tornou-se um input fundamental para os mecanismos de tomada de decisão das companhias [22, 45]. As empresas de eletricidade são altamente vulneráveis a crises económicas, uma vez que, em geral, não conseguem passar os seus custos excessivos para o mercado retalhista [77] e, uma vez que o preço depende de variáveis como meteorologia (temperatura, velocidade do vento, precipitação, etc.) e da intensidade de negócio e das atividades do dia-a-dia (pico vs vazio, dias da semana vs fim-de-semana, feriados e pontes, etc.) apresenta uma dinâmica que não é observada em mais nenhum mercado, com sazonalidade diária, semanal e anual, e com picos de preço abruptos de pouca duração e, em termos gerais, impossíveis de antecipar. Esta volatilidade de preços torna a previsão de preços particularmente interessante para gestores de portfólio, seja a curto ou a longo prazo. Uma companhia de eletricidade ou grande consumidor industrial que seja capaz de prever corretamente os preços do mercado grossista e a sua volatilidade, pode ajustar a estratégia de oferta da sua produção/seu consumo de maneira a reduzir o risco ou maximizar os ganhos no mercado à vista. Neste trabalho abordo a dinâmica do mercado de eletricidade ibérico (Operador de Mercado Iberico - Polo Español (OMIE)), revendo o estado da arte dos métodos de previsão de preços de eletricidade, e introduzo uma nova técnica de previsão de preços de eletricidade, através da previsão da sua dinâmica subjacente, as curvas de mercado da procura e oferta. Com este método é possível prever, não só o preço de eletricidade para as próximas horas, mas também as próprias curvas de oferta, o que pode ser utilizado na gestão de risco ao melhor a capacidade de programar as suas unidades de geração.Os resultados do modelo são analisados e comparados com outros modelos já utilizados na industria

    Forecasting in Mathematics

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    Mathematical probability and statistics are an attractive, thriving, and respectable part of mathematics. Some mathematicians and philosophers of science say they are the gateway to mathematics’ deepest mysteries. Moreover, mathematical statistics denotes an accumulation of mathematical discussions connected with efforts to most efficiently collect and use numerical data subject to random or deterministic variations. Currently, the concept of probability and mathematical statistics has become one of the fundamental notions of modern science and the philosophy of nature. This book is an illustration of the use of mathematics to solve specific problems in engineering, statistics, and science in general
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