Over time, product demand has become increasingly critical to the development of businesses and society. Belvedere and Goodwin (2017) state that demand forecasting is vital for industries in a speedy fashion, as they are challenged with short-term and highly volatile sales time series. The importance of demand forecasting is not only in providing essential forecasts through statistical methods to provide a base forecast but in understanding and managing human factors in the forecasting process, such as the emotions and preferences of the forecasters and their knowledge of the product, which can affect the outcome of the forecast. Effective demand forecasting requires balancing these factors to ensure that the forecast is as close as possible to the actual sales situation, thus helping firms make informed inventory and production decisions in unstable markets. Fu and Chien (2019) propose that, in fact, demand forecasting provides key inputs for various strategic decisions in supply chain management, including capacity planning, inventory control, and demand fulfilment. Liang et al. (2024) point out that accurate and reliable demand forecasting is a vital presence for significant retailers today, as the results of demand forecasting will directly affect the retailers' assortment planning, store location, and production planning. Kück and Freitag (2020) point out that demand forecasting is more important than product quality, as it directly impacts the ability to manage inventory and operating costs. Trapero et al. (2023) state that demand forecasting is critical in supply chain management. Inventory control policies are directly affected by the accuracy of probabilistic demand forecasts. Punia and Shankar (2022) state that high-quality demand forecasts are essential for the future and growth of a business, so there is a need to ensure the accuracy and quality of the data when making demand forecasts for a product. Lee (2020) suggests that accurate demand forecasting is an essential and highly challenging problem. This is because the results of snowball forecasting will directly affect the organization's future growth and planning. Rodrigues et al. (2024) point out that inaccurate demand forecasting will directly affect society's future ecological and developmental status. Therefore, accurate product demand forecasting is a necessity for the development of society, which will help alleviate the burden on society and the environment in the future. Chien et al. (2023) point out that effective demand forecasting will help enterprises ensure customer satisfaction and minimize the enterprises' inventory stocking. It reduces the amount of stock available in the firm's inventory. At the same time, the highly variable demand size for products and time intervals makes the current demand forecasting problem challenging. Dou et al. (2018) pointed out that in the development of enterprises in various industries, the internal and external difficulties from the enterprise itself will increase the risk of supply and demand imbalance of the enterprise itself. This is because when the enterprise's supply chain is not able to produce the number of products to meet the demand of the customer, the enterprise's market share and customer satisfaction decline, making the enterprise lose its competitiveness in the market, and when the share of the production of the product is too much will increase the risk of the enterprise's inventory. An excess share of products produced will increase inventory risk and reduce the company's profitability, so accurate demand forecasting becomes essential for the company's future development. Tadayonrad and Ndiaye (2023) explored the importance of demand forecasting and safety stock determination in supply chain planning. Demand forecasting predicts future demand for a product or service by analyzing historical data and other external and internal factors to reduce inventories and overproduction. Xu et al. (2024) proposed a new double-layer grey prediction model to improve the performance of cold chain logistics demand prediction. This model adapts to data features and generates corresponding background sequences to adjust parameters. Merge the time response functions generated by the double-layer structure using a differential evolution algorithm. Compared with existing similar models, this model extends its applicability and can provide higher accuracy for data sequences with high development rates. This model outperforms classical grey models and their extensions in terms of prediction accuracy.
As more and more enterprises begin to pay attention to product demand forecasting, the methods of demand forecasting have started to increase gradually. Ni et al. (2022) pointed out that the comprehensive salesperson opinion method, expert opinion method, market experiment method, time series analysis method and statistical demand analysis method are the more common methods of demand forecasting in the market at present. With the progress of scientific research, scholars have been improving the biochemistry of demand forecasting methods, and there are currently three standard methods for predicting product demand: time series, deep learning, and combinatorial algorithms. Lee and Kim (2024) proposed a prediction model that combines dynamic simulation and regression models to better predict product demand. Steenbergen and Mes (2020) proposed a demand forecasting method called DemandForest by combining the demand forecasting methods of K-means clustering, Random Forest, and Quartile Regression Forest by clustering analysis of the demand patterns and introducing the intra-period. This machine learning method is capable of forecasting newly launched products using historical sales data and product characteristics to assist in the inventory management of new products. Selim Türkoğlu et al. (2024) proposed a robust short-term multivariate multistep forecasting framework for demand forecasting using temporal convolutional networks (TCNs) that are resistant to missing or erroneous data and can predict demand for new products. That can resist the shadow of missing or inaccurate data. Xu et al. (2017) proposed a six-step multistage combinatorial forecasting model to predict demand for product services with a hierarchical service structure. The model incorporates the advantages of method combination forecasting and information combination forecasting. Validated with an air compressor service prediction case study, the model's in-sample and out-of-sample test results show that it outperforms a single prediction model and its direct combination. The method can be flexibly customized for other product-service demand forecasting scenarios and is particularly suitable for dealing with stratified time series data. Ji Chen et al. (2024) proposed a prediction method that combines the Boruta algorithm (Boruta), bidirectional long short-term memory (BiLSTM), and convolutional neural network (CNN). Through comparative analysis, it is shown that the performance of the hybrid CNN BiLSTM model is superior to the benchmark model. Robustness testing and robustness testing confirm that the proposed model has appropriate generalization ability, which is of great help for demand prediction. Wu et al. (2024) proposed a novel dual correction model based on knowledge extraction called the Knowledge-Based Dual Correction Model (KbBcM). KbBcM utilizes prior and posterior knowledge to achieve effective lag-free prediction. Extract prior knowledge in the form of sequence and feature information using an autoregressive long short-term memory (AR-LSTM) network and a newly proposed lagged penalty attention (LPA) module. In addition, a hybrid stacked LSTM network is used to obtain preliminary prediction results, which are then corrected using a masked weighted Markov chain (MWMC) based on posterior knowledge. In response to the limitations of the current focus on absolute error indicators, we have also introduced a new mean prediction trend effectiveness (MPTE) to comprehensively evaluate the effectiveness of non-lagged prediction performance.
Machine learning demonstrates diverse approaches and comprehensive analytical capabilities in demand forecasting. It integrates traditional methods, such as salesperson opinion, expert opinion, market experiments, modern time series and statistical analysis techniques, with extensive data analysis using multidimensional metrics. Deep learning algorithms, particularly LSTM, capture complex patterns in time series data. In contrast, ensemble learning methods like XGBoost and RF enhance the accuracy and generalization of predictions. Existing research on machine learning has achieved notable progress in improving time series analysis and statistical demand forecasting. This includes enhancing forecast accuracy in small sample environments, accounting for the impact of related product demand, preventing overfitting in high-dimensional time series data, optimizing inventory management through cluster analysis and quantile regression, and developing multilevel combinatorial forecasting models to enhance forecasting performance for products with hierarchical service structures. However, challenges remain, such as overfitting issues, the inability of traditional methods to capture complex nonlinear relationships, difficulties in forecasting accuracy and inventory management for newly launched products, and the need for flexibility across different forecasting scenarios. To address these challenges, this paper proposes a diversified integrated model (RXOEL-X) that combines the strengths of Blending linear regression, RF, XGBoost, OLS, ElasticNet, and LSTM, with XGBoost serving as a sub-model. This model improves multi-product demand forecasting performance by enhancing accuracy, preventing overfitting, managing complex nonlinear patterns, flexibly adapting to market changes, and effectively analyzing high-dimensional data.
Guo et al. (2021) proposed a novel hybrid forecasting method for predicting seasonal manufacturing demand. The approach combines the strengths of the Prophet model, which is responsible for capturing seasonal fluctuations and determining the input variables for the SVR model, and the SVR model, which is used to identify nonlinear patterns. This hybrid PROPHET-SVR approach can customize holiday impacts and seasonal variations and effectively account for prediction residuals, thus improving prediction accuracy. The study results show that the hybrid method outperforms other traditional forecasting techniques in terms of forecasting performance. Joseph et al. (2022) explored the importance of accurate product demand forecasting for business decision-makers to formulate strategies in a changing market environment and developed a CNN BiLSTM framework incorporating the Lazy Adam optimizer to improve the accuracy of shop merchandise demand forecasting. He et al. (2023) used two LSTM-based networks as the basic framework for the demand forecasting model, on which horizontal and vertical sequential forecasting model improvements were carried out to forecast the relevant product demand. Li (2024) proposed A cascaded hybrid neural network commodity demand prediction model based on multimodal data, which integrates historical order information and product evaluation sentiment data by constructing multimodal data feature clustering and using a spatial feature fusion strategy. Thus, the advantages of bi-directional long- and short-term memory networks and bi-directional gated recurrent unit networks are combined to provide product forecasting accuracy for product inventory management. Ma and Liu (2024) proposed a CNN-LSTM-Attention algorithm to predict product demand and demonstrated through experiments that the CNN-LSTM Attention model outperforms 1DCNN-LSTM-Attention, CNN-LSTM, LSTM, SVR-based model, and BP neural network model in product demand prediction, with a prediction accuracy of 97.50%, verifying the practicality and effectiveness of the model.
Liao et al. (2024) pointed out that in current demand forecasting, traditional models often face the challenge of capturing and analyzing complex time series data. To solve the dilemma better, they proposed an innovative co-training model based on empirical modal decomposition (EMD), which employs a two-layer optimization strategy and combines a differential evolutionary algorithm and interactive fuzzy planning to optimize the training of neural networks derived from EMD decomposition subsequences for neural network training. This co-training mechanism effectively overcomes the problem of capturing the complex relationships among subsequences, thus improving the prediction accuracy, and providing a new perspective for applying intelligent prediction in the field of tourism demand. Dong et al. (2023) pointed out that since human behaviours constantly change, the demand prediction will change as well, and therefore proposed a spatiotemporal feature enhancement model to ensure the completeness of the demand features and applied the steady-state analysis method to learn the spatiotemporal features, which is the best way to ensure the completeness of the demand features. Steady-state analysis was used to learn the spatial and temporal features, a convolutional filter was employed, and the feature sequences were transformed into image sequences, maintaining the correlation between the spatial and temporal features. Jin et al. (2024) proposed a hybrid forecasting method combining the System Dynamics (SD) model with the Power Generation Portfolio Planning (PGMP) model. This approach reduced the forecasting error and carried out the demand forecasting exercise by correcting the Markov chain state transfer matrix in the PGMP model. Ye et al. (2024) proposed a Fourier time-varying grey model (FTGM) to improve the accuracy of seasonal demand forecasting. The model combines the advantages of grey forecasting methods, i.e., the ability to process finite datasets efficiently, and the ability of the Fourier function to approximate time-varying parameters to capture and represent seasonal variations efficiently. The FTGM is characterized by a data-driven selection algorithm capable of adaptively determining the model without a priori knowledge. Fourier order of the model without a priori knowledge. Using the well-known M5 competitive dataset and comparing FTGM with state-of-the-art forecasting techniques based on grey models, statistical methods, and neural network approaches, experimental results show that FTGM outperforms other popular seasonal forecasting methods in terms of standard accuracy metrics.
In summary, intelligent forecasting has demonstrated the efficacy of integrating multiple modeling approaches to enhance accuracy. These approaches include global model training for linear and non-linear analysis and advanced neural network architectures, such as LSTM, for complex sequential data. Additionally, historical order data and product evaluation sentiment data are incorporated using multimodal data and cascading hybrid neural network models to improve forecasting accuracy. Intelligent forecasting also addresses complex time series through EMD and co-training mechanisms, utilizing spatiotemporal features to enhance the model's learning capabilities. This approach employs steady-state analysis methods, SD and PGMP to efficiently capture seasonal variations. Despite its ability to handle a wide range of complex scenarios, intelligent forecasting still faces challenges related to data quality, model generalizability and interpretability, and adapting to environmental dynamics. To address these challenges, this paper proposes a diversified integrated model (RXOEL-X), which combines the strengths of various forecasting techniques to enhance adaptability and robustness. This model optimizes data usage and improves interpretability, thereby overcoming the limitations of existing intelligent forecasting methods and providing more accurate, reliable, and interpretable forecast results.
Compared to other standard demand forecasting methods (e.g., Salesperson Opinion Method, Time Series Analysis, Statistical Demand Analysis), as well as models proposed in other studies (e.g., XGBoost-based models, Multi-Level Combined Forecasting Models, DemandForest, LSTM-based models), the RXOEL-X model stands out due to its integration of multiple forecasting techniques. This model offers a robust and precise framework, particularly adept at managing big data and high-dimensional time series data, thereby potentially optimizing inventory cost management.
Table 1 provides a summary of the forecasting models and their performance from the literature.
Table 1
List of related literature
Model | Contribution |
XGBoost | Improving the accuracy of e-commerce product prediction in small sample data environments combines multidimensional metrics, fuses similar metrics using the entropy method, incorporates Logistic functions and regularization terms, and optimizes using a greedy algorithm. |
AR | Considering the importance of associated product demand trends for forecasting, forecasting accuracy is improved by incorporating associated product demand as an additional predictor into the model, and a variable simplification scheme is introduced to prevent overfitting. |
Demand Forest | Combines K-means clustering, RF, and quantile regression forests to optimize inventory management and predict new product launches with improved forecasting accuracy. |
TCNs | Robust short-term multivariate multistep prediction framework that resists the effects of missing or erroneous data. |
Multilevel Combined Prediction Model | The fusion approach combines the advantages of forecasting and information combination prediction and is suitable for dealing with product-service requirements in a hierarchical service structure. Validation has shown that it outperforms a single forecasting model and its combinations. |
Co-Training Model Based on EMD | A two-layer optimization strategy, combining differential evolutionary algorithm and interactive fuzzy planning, is used to optimize neural network training, overcome the complex relationship between sub-sequences, and improve prediction accuracy. |
Spatiotemporal Feature Enhancement Model | Spatiotemporal features are learned by means of a steady-state analysis method using a convolutional filter, and the sequence of features is transformed into a sequence of images, maintaining the correlation between spatial and temporal features. |
SD&PGMP | Reducing prediction errors and correcting the Markov chain state transfer matrix in the PGMP model. |
FTGM | To improve the accuracy of seasonal demand forecasting, a data-driven selection algorithm is used to adaptively determine the Fourier order of the model by combining the advantages of grey forecasting methods and Fourier functions. |
PROPHET-SVR | Combine the strengths of the Prophet model and the Support Vector Regression (SVR) model to customize holiday impacts and seasonal variations and consider forecast residuals to improve accuracy. |
CNN BiLSTM | A framework incorporating the Lazy Adam optimizer for improving the accuracy of forecasting demand for goods in shops. |
Six-Step Multilevel Combinatorial Forecasting Model | It can be flexibly customized for other product-service demand forecasting scenarios and is particularly suitable for processing hierarchical time series data. |
Two Horizontal and Vertical Sequence Prediction Models Based on LSTM | The correlations inherent in long-term series are skillfully captured, thus correcting the limitations of traditional algorithms in managing complex and irregular data patterns. |
A Cascaded Hybrid Neural Network Commodity Demand Forecasting Model Based on Multimodal Data | Historical order information and product evaluation sentiment data are integrated by constructing multi-modal data feature clustering and utilizing spatial feature fusion strategies. The model combines the advantages of bi-directional long and short-term memory networks and bi-directional gated recurrent unit networks. |
RXOEL-X | Integrating the strengths of Blending Linear Regression, RF, XGBoost, OLS, ElasticNet, and LSTM with XGBoost as a sub-model, it improves prediction accuracy, prevents overfitting, handles complex non-linear patterns, adapts to market changes, and effectively analyses high-dimensional data. |