The Weibull distribution is widely applied in fields such as survival analysis, reliability engineering, failure analysis, and extreme value theory. Traditionally, Maximum Likelihood Estimation (MLE) has been commonly used to estimate the parameters of this distribution. In this paper, we derive a new formula for the mean absolute deviation (MAD) about the median. We use this formula to derive a MAD-based parameter-estimation method that is computationally simpler than MLE. We apply our results to analyze the survival times of breast cancer patients and insurance claim amounts, providing evidence from biomedical and actuarial domains. We estimate parameters using MLE, MAD, and quantile-based approaches. The results show that the proposed MAD-based approach is superior to the other two methods. It demonstrates the practical application of MAD methods in survival analysis and financial risk modeling of insurance claims, where accurate modeling is crucial for understanding extreme outcomes.
Weibull
Almeida, J. B., (1999). Application ofWeibull Statistics to the Failure of Coatings. Journal of Materials Processing Technology. https://doi.org/10.1016/S0924-0136(99)00177-6.
Balakrishnan, N., Kateri, M., (2008). On the Maximum Likelihood Estimation of Parameters of Weibull Distribution Based on Complete and Censored Data. textitStatistics & Probability Letters. https://doi.org/10.1016/j.spl.2008.05.019.
Bloomfield, P., Steiger, W. L., (1984). Least Absolute Deviations, https://doi.org/10.1007/978-1-4684-8574-5.
Cancho, V. G., Macera, M. A. C., Suzuki, A. K., Louzada, F., and Zavaleta, K. E. C., (2020). A New Long-term Survival Model with Dispersion Induced by Discrete Frailty. Lifetime Data Analysis, 26(2). https://doi.org/10.1007/s10985-019-09472-2.
Carroll, K .J., (2003). On the Use and Utility of the Weibull Model in the Analysis of Survival Data. Controlled Clinical Trials. https://doi.org/10.1016/S0197-2456(03)00072-2.
Chen, Q., Gerlach, R., (2011). The Two-sided Weibull Distribution and Forecasting Financial Tail Risk, University of Sydney Business School, Discipline of Business Analytics.
Cohen, A. C., (1965). Maximum Likelihood Estimation in the Weibull Distribution Based on Complete and Censored Samples. Technometrics. https://doi.org/10.1080/00401706.1965.10490300.
Cohen, C. A., Whitten, B., (1982). Modified Maximum Likelihood and Modified Moment Estimators for the Three-Parameter Weibull Distribution. Communications in Statistics - Theory and Methods. https://doi.org/10.1080/03610928208828412.
Feller, J., (1956). Probability Theory and Applications. https://doi.org/10.1016/S0895-7177(01)00109-1.
Fogliatto, M. S. S., Santos, T. M. O., Bessani, M., and Maciel, C., (2019). Survival Analysis of Electrical Power Distribution Systems Using Weibull Regression, Proceedings of the 2019 SBAI. https://doi.org/10.17648/sbai-2019-111513.
Gebizlioglu, O. L., Senoglu, B., and Kantar, Y. M., (2011). Comparison of Certain Valueat- Risk Estimation Methods for the Two-ParameterWeibull Loss Distribution. Journal of Computational and Applied Mathematics. https://doi.org/10.1016/j.cam.2011.01.044.
Hamza, A., (2023). A Bayesian Approach to Weibull Distribution with Application to Insurance Claims Data. textitJournal of Reliability and Statistical Studies. https://doi.org/10.13052/jrss0974-8024.1611.
Hazim, K., Abdul Sada, M. T., (2025). The Survival Power Weibull Distribution With Application, Statistics, Optimization & Information Computing. https://doi.org/10.19139/soic-2310-5070-2318.
Hirst, T. C., Sena, E. S., and Macleod, M. R., (2021). Using Median Survival in Metaanalysis of Experimental Time-to-Event Data. Systematic Reviews, 10. https://doi.org/10.1186/s13643-021-01824-0.
Hortobagyi, G. N., Stemmer, S. M., Burris, H. A., Yap, Y.-S., and Sonke, G. S., (2022). Overall Survival with Ribociclib plus Letrozole in Advanced Breast Cancer. New England Journal of Medicine, 386(10). https://doi.org/10.1056/nejmoa2114663.
Imran, M., Alsadat, N., (2024). The Development of an Extended Weibull Model with Applications to Medicine, Industry and Actuarial Sciences. Scientific Reports. https://doi.org/10.1038/s41598-024-61308-8.
Jacquelin, J., (1993). Generalization of the Method of Maximum Likelihood (Insulation Testing). IEEE Transactions on Electrical Insulation. https://doi.org/10.1109/14.192241.
Jokiel-Rokita, A., Piatek, S., (2024). Estimation of Parameters and Quantiles of theWeibull Distribution. Statistical Papers. https://doi.org/10.1007/s00362-022-01379-9.
Kang, D., Ko, K. and Huh, J., (2018). Comparative Study of Different Methods for Estimating Weibull Parameters: A Case Study on Jeju Island, South Korea. Energies. https://doi.org/10.3390/en11020356.
Olver, F. W., Lozier, D. W., Boisvert, R. F., and Clark, C. W., (2010). NIST Handbook of Mathematical Functions, Cambridge University Press, New York.
Pham-Gia, T., Hung, T. L., (2001). The Mean and Median Absolute Deviations. https://doi.org/10.1090/S0002-9947-1956-0090927-3.
Pinsky, E., Zhang, W. and Wang, Z., (2024). Pareto Distribution of the Forbes Billionaires. Computational Economics. https://doi.org/10.1007/s10614-024-10730-1.
Pobockova, I., Sedliackova, Z., (2014). Comparison of Four Methods for Estimating the Weibull Distribution Parameters. Applied Mathematical Sciences. https://doi.org/10.12988/ams.2014.45389.
Quiroz Flores, A., (2024). Machine Learning for Survival Analysis. In Oxford Handbook of Engaged Methodological Pluralism in Political Science, Vol. 1. https://doi.org/10.1093/oxfordhb/9780192868282.013.48.
Teimouri, M., Hoseini, S. M. and Nadarajah, S., (2011). Comparison of Estimation Methods for theWeibull Distribution. textitStatistics. https://doi.org/10.1080/02331888.2011.559657.
Welch, B. L., Johnson, N. L. and Kotz, S., (1972). Distributions in Statistics: Continuous Univariate Distributions. Journal of the Royal Statistical Society. Series A (General), 135(3). https://doi.org/10.2307/2344623.
Yoosefi, M., Baghestani, A. R. and Khadembashi, N., (2018). Survival Analysis of Colorectal Cancer Patients Using Exponentiated Weibull Distribution. International Journal of Cancer Management, 11(3). https://doi.org/10.5812/ijcm.8686.