Table 2 Summary of machine-learning models used for EOL demand forecasting.

From: A machine learning framework for long-term forecasting of spare part demand in end-of-life product scenarios

Model

Type

Core assumption/learning principle

Key strengths

Limitations in EOL context

Elasticnet

Linear regression with L1 + L2 regularization

Demand follows quasi-linear trend; correlated features penalized proportionally

Handles multicollinearity; interpretable coefficients

Cannot capture non-linear or discontinuous demand behaviour; sensitive to zero-inflated data

Huber regressor

Robust linear model combining least-squares and absolute loss

Outliers are limited by Huber threshold; assumes smooth residual distribution

Resistant to noise and extreme values

Linear formulation underfits sparse, highly non-stationary data

Random forest

Ensemble of decision trees using bootstrap aggregation

Non-parametric; learns non-linear interactions without feature scaling

High accuracy, low variance; interpretable feature importance; stable on sparse data

Large memory footprint; limited extrapolation beyond training range

XGBoost

Gradient-boosted tree ensemble

Sequential residual correction; regularized boosting for overfitting control

Fast training; strong generalization; handles mixed feature types

Prone to overfitting on small datasets; sensitive to learning-rate tuning

LightGBM

Leaf-wise gradient boosting with histogram optimization

Greedy leaf growth to minimize loss

Very fast on large datasets; efficient parallelization

May overfit or produce unstable forecasts under high sparsity

Catboost

Ordered boosting with categorical feature encoding

Uses permutation-driven boosting and target statistics

Handles categorical variables efficiently; reduced overfitting bias

Sensitive to noise; can produce abrupt forecasts when historical trend shifts

Proposed RF + decay blending

Random Forest combined with exponential-decay modulation

ML prediction dynamically adjusted by lifecycle decay kernel

Physically interpretable; robust long-horizon extrapolation; suitable for SKU-level deployment

Requires empirical tuning of blending coefficient; current version deterministic (to be extended with uncertainty-aware methods)