Communications on Applied Nonlinear Analysis ISSN: 1074-133X Vol 32 No. 10s (2025) 3545 https://internationalpubls.com Classical and Bayesian Estimation for a New Long Tailed Distribution: Modi-Lomax Distribution Surinder Kumar1, Rahul Shukla1, *, Bhupendra Meena1 1Babasaheb Bhimrao Ambedkar University, Vidya Vihar, Raebareli Road, Lucknow – 226025, India Email: surinderntls@gmail.com1, rahul.shukla.stats@gmail.com1, *(corresponding author), bhupendrakm57@gmail.com1 Article History: Received: 19-09-2024 Revised: 24-10-2024 Accepted: 11-11-2025 Abstract: This paper presents the new Modi-Lomax distribution (MOLD), a three-parameter distribution obtained by using the Modi family generator to include one extra shape parameter in the standard two-parameter Lomax distribution. We establish extensive statistical properties such as survival function, hazard rate function, moment generating function, quantile function with quartile representations, mean residual lifetime, order statistics, and stress-strength reliability. For parameter estimation, we use maximum likelihood estimation and Bayesian methods with Gamma priors under squared error loss functions, comparing their performances based on bias and mean square error criteria. The practical usefulness of MOLD is shown through the analysis of one real data set of bladder cancer patients and a comparative analysis with a number of alternative distributions. Results validate the superior flexibility and goodness-of-fit of the suggested distribution under different test criteria, emphasizing its flexibility to model data with diverse failure rate shapes and aging behaviours. This paper makes MOLD a great contribution to lifetime distributions with prominent practice in reliability engineering and survival analysis. Keywords: Lomax Distribution, Modi Family, Maximum Likelihood Estimation, Bayesian Estimation, Stress-Strength Model 1. Introduction Probability distributions serve as fundamental tools in statistical modelling across various scientific fields. With the growing complexity of observed phenomena, statistical research has increasingly focused on developing more adaptable distributions through mathematical transformations, weighting schemes, and mixture techniques. In recent years, the generalization of probability models has become particularly prominent, with various approaches available, such as Alpha Power Transformation (APT), exponentiation, mixture and weighted techniques, power transformations, among others. The Lomax distribution, or Lomax-Pareto Type II distribution, has found its place as a useful statistical model in reliability studies and as well as distribution theory. The distribution gained popularity because it is easily flexible in representing and modelling heavy-tailed behaviours in various fields of mathematics [(Harris, 1968); (Bryson, 1974)]. Initial theoretical contributions by (Balkema & De Haan, 1974) laid the foundation of the Lomax distribution's application in reliability modelling and life testing. (Arnold, 1983) further developed a detailed framework that linked the Lomax distribution to the rest of the Pareto family. (Johnson et al., 1994) continued from such foundations, providing elaborate details about the properties and features of the distribution that cemented its place in statistical literature. mailto:surinderntls@gmail.com mailto:rahul.shukla.stats@gmail.com1 mailto:bhupendrakm57@gmail.com Communications on Applied Nonlinear Analysis ISSN: 1074-133X Vol 32 No. 10s (2025) 3546 https://internationalpubls.com The statistical properties of Lomax distribution have been well explored. (Ahsanullah, 1991) made noteworthy contributions by studying record values that came from Lomax-distributed variables. (Balakrishnan & Ahsanullah, 1994) derived significant recurrence relations among moments of record values from the Lomax distribution. (Atkinson & Harrison, 1978) illustrated the Lomax distribution's suitability in modelling income and wealth data. (Tadikamalla, 1980) formulated significant relationships among the Lomax and Burr family of distributions. The failure rate characteristics of Lomax model were also comprehensively studied by (Chahkandi et al., 2009), who identified that it comes under the class of decreasing failure rate distributions. The literature has seen significant development in extensions of the standard Lomax distribution. (Ashour & Eltehiwy, 2013) presented Transmuted Exponential Lomax (TEL) model. (Rady et al., 2016) used the power transformation on Lomax distribution (PoL). (Shabbir et al., 2018) contributed to Lomax family by creating Rayleigh Lomax distribution (RaL). (Joshi & Kumar, 2021) came up with the Poisson Inverted Lomax (PoIL) distribution. Another four-parameter distribution is Exponentiated odd Lomax, developed by (Dhungana & Kumar, 2022). There is another four-parameter distribution competitive to our study is Power XLindley (PXLin) by (Elgarhy et al., 2025) Some of the recent contributions to the Lomax family is Log-Lomax (LoL) by (Ishaq et al., 2025). (Modi et al., 2020) introduced the Modi family of distributions, demonstrating its adaptability for modelling diverse phenomena in engineering, economics, and finance. Subsequent studies have expanded this family - (Kumawat et al., 2024) developed the Modi-Weibull distribution, examining its statistical properties, while (Ndayisaba et al., 2023) proposed the Modi exponentiated exponential distribution, analysing its mathematical features and practical applications. In a recent study, (Kumar et al., 2025) proposed a new Modi-Rayleigh distribution, demonstrating its superior performance relative to existing distributions generated through the identical Modi transformation approach. These methods enable statisticians to refine existing distributions to better represent complex data characteristics, such as heavier tails, greater skewness, or unique hazard rate patterns, which conventional distributions may fail to capture adequately. This manuscript introduces the Modi-Lomax distribution (MOLD) using the Modi-family generator method. Our primary motivation stems from adding one new shape parameters to an existing long- tailed distribution, enhancing its ability to fit failure time data containing extremely small values. We compare our proposed model with well-established lifetime distributions to demonstrate its flexibility in fitting real-world datasets. The article employs both classical and Bayesian estimation procedures to estimate the parameters of our proposed model. For classical estimation, we utilize the maximum likelihood method, while our Bayesian approach incorporates gamma priors and square error loss function (SELF). The manuscript is organized as follows: Section 2 introduces the Modi-Lomax (MOLD) distribution. Section 3 presents reliability analysis of MOLD. Section 4 covers the statistical properties, moment generating function, quantile function and order statistics, respectively. Section 6 covered the detailed parameter estimation using both maximum likelihood and Bayesian approaches with gamma priors and SELF. Section 7 presents simulation studies, Section 8 demonstrates applications to real-world Communications on Applied Nonlinear Analysis ISSN: 1074-133X Vol 32 No. 10s (2025) 3547 https://internationalpubls.com datasets with comparative analysis, and Section 9 concludes with a summary of findings. In section 10, we discussed the future scope of the article. 2. Modi-Lomax Distribution The Modi family generator (Modi et al., 2020) is widely employed across various fields due to its capacity to introduce two additional shape parameters into existing lifetime models, thereby enhancing their flexibility for modelling real-world datasets. If f(t) and F(t) represent the probability density function (pdf) and cumulative distribution function (cdf), respectively, of an existing lifetime distribution, then the pdf g(.) and cdf G(.) of the new Modi family distribution are given by: 𝑔(π‘₯) = 𝛼𝛽(1+𝛼𝛽)𝑓(π‘₯) (𝛼𝛽+𝐹(π‘₯)) 2 ; π‘₯ > 0, 𝛼 > 0, 𝛽 > 0 ( 1) 𝐺(π‘₯) = (1+𝛼𝛽)𝐹(π‘₯) 𝛼𝛽+𝐹(π‘₯) ; π‘₯ > 0, 𝛼 > 0, 𝛽 > 0 ( 2) In the Modi family generator, there are two shape parameters viz. Ξ± and Ξ². We combine these two shape parameters and introduce single shape parameter ΞΎ = Ξ±Ξ². The motivation behind this substitution is that, we want to check the joint effect of these two-shape parameter after the fusion with Lomax distribution. If t follows the Lomax distribution, so the pdf and cdf of t are as follows: 𝑓(𝑑, πœ†, πœƒ) = πœ† πœƒ (1 + 𝑑 πœƒ ) βˆ’(πœ†+1) ; 𝑑 > 0, πœ† > 0, πœƒ > 0 ( 3) 𝐹(𝑑, πœ†, πœƒ) = 1 βˆ’ (1 + 𝑑 πœƒ ) βˆ’πœ† ; 𝑑 > 0, πœ† > 0, πœƒ > 0 ( 4) The MOLD is created from the Lomax distribution by putting Eq. (3) and Eq. (4), respectively, into Eq. (1) and Eq. (2). As a result, the MOLD's pdf is ascertained as 𝑔(𝑑) = πœ‰(1+πœ‰)πœ†πœƒβˆ’πœ†(πœƒ+𝑑)βˆ’(πœ†+1) [(1+πœ‰)πœƒβˆ’πœ†βˆ’(πœƒ+𝑑)βˆ’πœ†] 2 ; 𝑑 > 0, πœ‰ > 0, πœ† > 0, πœƒ > 0 ( 5) The corresponding cdf of MOLD is given as 𝐺(𝑑) = (1+πœ‰)[πœƒβˆ’πœ†βˆ’(πœƒ+𝑑)βˆ’πœ†] [(1+πœ‰)πœƒβˆ’πœ†βˆ’(πœƒ+𝑑)βˆ’πœ†] ; 𝑑 > 0, πœ‰ > 0, πœ† > 0, πœƒ > 0 ( 6) Communications on Applied Nonlinear Analysis ISSN: 1074-133X Vol 32 No. 10s (2025) 3548 https://internationalpubls.com Figure 1. PDF plots of MOLD for different parametric values of ΞΎ, Ξ» and ΞΈ. Figure 2. 3D PDF plots of MOLD for varying ΞΎ, Ξ» and ΞΈ values. 3. Reliability Characteristics of MOLD This section presents the derivation of essential reliability characteristics for the MOLD distribution, specifically addressing survival function, hazard rate, reverse hazard rate, cumulative failure rate, and the Mills ratio. 3.1. Survival Function The survival function S(t) is one of important reliability measure in the reliability realm. It is defined as S(t)β€ˆ = β€ˆ1β€ˆ βˆ’ β€ˆG(t) where G(t) is the cumulative density function. From Eq. (6), we get the survival function for MOLD as following 𝑆(𝑑) = πœ‰(πœƒ+𝑑)βˆ’πœ† πœƒβˆ’πœ†(1+πœ‰)βˆ’(πœƒ+𝑑)βˆ’πœ† ( 7) Communications on Applied Nonlinear Analysis ISSN: 1074-133X Vol 32 No. 10s (2025) 3549 https://internationalpubls.com Figure 3. Survival function plots for MOLD distribution. 3.2. Hazard Rate and Inverse Hazard Rate Function The hazard rate function H(t)β€ˆ = β€ˆ g(t) S(t) β€ˆand the reversed hazard rate function Hβ€²(t) = g(t) G(t) are important quantities characterizing life time phenomena. For the MOLD distribution, they are given as 𝐻(𝑑) = πœ†(1+πœ‰) (πœƒ+𝑑)(1+πœ‰)βˆ’πœƒπœ†(πœƒ+𝑑)1βˆ’πœ† ( 8) and 𝐻′(𝑑) = πœ‰πœ†πœƒβˆ’πœ†(πœƒ+𝑑)βˆ’(πœ†+1) [(1+πœ‰)πœƒβˆ’πœ†βˆ’(πœƒ+𝑑)βˆ’πœ†][πœƒβˆ’πœ†βˆ’(πœƒ+𝑑)βˆ’πœ†] ( 9) 3.3. Cumulative Hazard Rate The cumulative hazard rate, measures the total risk that an event will occur by some specified time. The function is actually the integration of the hazard rate over time intervals, which illustrates how probability of the event occurrence increases with time. It is defined as Ξ”(𝑑) = βˆ’ log(𝑆(𝑑)) Hence for the MOLD, it is given as Ξ”(𝑑) = βˆ’ log [ ΞΎ(ΞΈ + 𝑑)βˆ’Ξ» ΞΈβˆ’Ξ»(1 + ΞΎ) βˆ’ (ΞΈ + 𝑑)βˆ’Ξ» ] π›₯(𝑑) = βˆ’ π‘™π‘œπ‘”(πœ‰) + πœ† π‘™π‘œπ‘”(πœƒ + 𝑑) + π‘™π‘œπ‘”[πœƒβˆ’πœ†(1 + πœ‰) βˆ’ (πœƒ + 𝑑)βˆ’πœ†] ( 10) 3.4. Mills Ratio The Mills ratio (M.R) for the MOLD is obtained as M.R = 𝐺(𝑑) 𝑆(𝑑) M.R = (1 + πœ‰) [(1 + 𝑑 πœƒ ) πœ† βˆ’ 1] ( 11) Communications on Applied Nonlinear Analysis ISSN: 1074-133X Vol 32 No. 10s (2025) 3550 https://internationalpubls.com Figure 4. Hazard function plots for MOLD distribution 3.5. Cumulative Hazard Rate The mean residual lifetime (MRL) represents the expected remaining lifespan of a subject given that it has survived to a particular time point. This measure provides valuable insight into the conditional life expectancy and is particularly useful for understanding survival patterns in different phases of the study period. MRL = E[(π‘₯ βˆ’ 𝑑)|π‘₯ > 𝑑] = ∫ (π‘₯ βˆ’ 𝑑)𝑓(π‘₯)𝑑π‘₯ ∞ 𝑑 𝑆(𝑑) For the MOLD, MRL is derived as MRL = (ΞΈ + 𝑑) Ξ» βˆ’ 1 ; Ξ» > 1 This shows that the MRL for the MOLD increases linearly with t, with the rate determined by the parameter Ξ». This is a characteristic of distributions with the lack of memory property similar to the exponential distribution, but with a different structure. 4. Statistical Properties of MOLD 4.1. Moment Generating Function Theorem 1. If X is the MOLD variable having pdf given in Eq. (5), then its moment generating function 𝑀π‘₯(𝑠) is given by 𝑀π‘₯(𝑠) = πœ‰(1 + πœ‰)πœ†πœƒβˆ’πœ†π‘’βˆ’π‘ πœƒ ∫ π‘’π‘ π‘’π‘’βˆ’(πœ†+1) [(1+πœ‰)πœƒβˆ’πœ†βˆ’π‘’βˆ’πœ†]2 𝑑𝑒 ∞ πœƒ ( 12) Proof. The MGF of MOLD is obtained from 𝑀π‘₯(𝑠) = 𝐸[𝑒𝑠π‘₯] = ∫ 𝑒𝑠𝑑 ∞ 0 𝑔(𝑑)𝑑𝑑 If we define L[g(t)](s)as the Laplace transformation of g(t), then 𝑀π‘₯(𝑠) = 𝐿[𝑔(𝑑)](βˆ’π‘ ) Communications on Applied Nonlinear Analysis ISSN: 1074-133X Vol 32 No. 10s (2025) 3551 https://internationalpubls.com where 𝐿[𝑔(𝑑)](𝑠) = ∫ π‘’βˆ’π‘ π‘‘βˆž 0 𝑔(𝑑)𝑑𝑑 Hence, we get 𝑀π‘₯(𝑠) = ΞΎ(1 + ΞΎ)Ξ»ΞΈβˆ’Ξ»π‘’βˆ’π‘ ΞΈ ∫ π‘’π‘ π‘’π‘’βˆ’(πœ†+1) [(1 + πœ‰)πœƒβˆ’πœ† βˆ’ π‘’βˆ’πœ†]2 𝑑𝑒 ∞ πœƒ Theorem 2. The rth moment about origin of MOLD is defined as ΞΌπ‘Ÿ β€² = 𝐸(π‘‘π‘Ÿ) = ΞΈπ‘Ÿ+Ξ» Ξ» βˆ‘ ( π‘Ÿ π‘˜ ) (βˆ’1)π‘˜B ( 1 βˆ’ (π‘Ÿ βˆ’ π‘˜) Ξ» + 1,1) (1 + ΞΎ)1βˆ’(π‘Ÿβˆ’π‘˜)/Ξ»βˆ’2 π‘Ÿ π‘˜=0 where, B(x,y) is the beta function. Proof. The rth moment about origin for the MOLD is obtained from the following expression using Eq.(5) ΞΌπ‘Ÿ β€² = 𝐸(π‘‘π‘Ÿ) = ∫ π‘‘π‘Ÿπ‘”(𝑑)𝑑𝑑 ∞ 0 Let 𝑒 = ΞΈ + 𝑑 𝐸(π‘‘π‘Ÿ) = ∫ (𝑒 βˆ’ ΞΈ)π‘ŸΞΎΞ»ΞΈβˆ’Ξ»(𝑒)βˆ’(Ξ»+1)(1 + ΞΎ) [(1 + ΞΎ)ΞΈβˆ’Ξ» βˆ’ π‘’βˆ’Ξ»]2 𝑑𝑒 ∞ ΞΈ Now we use second substitution 𝑣 = ( ΞΈ 𝑒 ) Ξ» 𝐸(π‘‘π‘Ÿ) = ΞΈπ‘Ÿ+Ξ» Ξ» ∫ (π‘£βˆ’1/Ξ» βˆ’ 1) π‘Ÿ 𝑣1/Ξ» (1 + ΞΎ βˆ’ 𝑣)2 𝑑𝑣 1 0 Now expanding (π‘£βˆ’1/Ξ» βˆ’ 1) π‘Ÿ = βˆ‘ (π‘Ÿ π‘˜ )(π‘£βˆ’1/Ξ») π‘Ÿβˆ’π‘˜ (βˆ’1)π‘˜π‘Ÿ π‘˜=0 using binomial expression, we get 𝐸(π‘‘π‘Ÿ) = ΞΈπ‘Ÿ+Ξ» Ξ» βˆ‘ ( π‘Ÿ π‘˜ ) (βˆ’1)π‘˜B ( 1 βˆ’ (π‘Ÿ βˆ’ π‘˜) Ξ» + 1,1) (1 + ΞΎ)1βˆ’(π‘Ÿβˆ’π‘˜)/Ξ»βˆ’2 π‘Ÿ π‘˜=0 4.2 Quantile Function Let 𝑑 ∼ MOLD(ΞΎ, Ξ», ΞΈ) and G(t) = p be the cdf of t, so the quantile function is defined as 𝑄(𝑝) = πΊβˆ’1(𝑝), for 0 < 𝑝 < 1 Hence the quantile function of MOLD is obtained as follows 𝑄(𝑝) = πœƒ [( 1+πœ‰βˆ’π‘ (1+πœ‰)(1βˆ’π‘) ) 1/πœ† βˆ’ 1] , 0 < 𝑝 < (1 + πœ‰) ( 13) The first, second and third quartile can be obtained from Eq. (13) by putting p = 1/4, 1/2 and 3/4, respectively. Communications on Applied Nonlinear Analysis ISSN: 1074-133X Vol 32 No. 10s (2025) 3552 https://internationalpubls.com The first quartile 𝑄1 = πœƒ [( 3+4πœ‰ 3(1+πœ‰) ) 1/πœ† βˆ’ 1] ( 14) The second quartile 𝑄2 = πœƒ [( 1+2πœ‰ (1+πœ‰) ) 1/πœ† βˆ’ 1] ( 15) The third quartile 𝑄3 = πœƒ [( 1+4πœ‰ (1+πœ‰) ) 1/πœ† βˆ’ 1] ( 16) 4.3 Order Statistics Consider a finite random sample consisting of observations t1, t2, … , tn drawn from the MOLD with pdf g(t) and cdf G(t). When these sample values are rearranged in non-decreasing sequence, the resulting ordered observations t1, t2, … , tn are called the order statistics of the sample, where: 𝑑(1) ≀ 𝑑(2) ≀ β‹― ≀ 𝑑(𝑛) The order statistic 𝑑(π‘Ÿ) corresponds to the π‘Ÿπ‘‘β„Ž smallest observation among the sorted sample values. Specifically, 𝑑(1) is the minimum value, 𝑑(2) is the second minimum, and this pattern continues until 𝑑(𝑛) which represents the maximum value in the sample. For any r where 1 ≀ π‘Ÿ ≀ 𝑛 the pdf of the π‘Ÿπ‘‘β„Ž order statistic is expressed as: π‘ž(π‘Ÿ)(𝑑) = 𝑛! (π‘Ÿβˆ’1)!(π‘›βˆ’π‘Ÿ)! 𝑔(𝑑)[𝐺(𝑑)]π‘Ÿβˆ’1[1 βˆ’ 𝐺(𝑑)]π‘›βˆ’π‘Ÿ ( 17) Putting the expression of pdf and cdf of MOLD from Eq. (5) and Eq. (6) respectively in Eq.(17), π‘ž(π‘Ÿ)(𝑑) = π‘š πœ†πœ‰(1+π‘›βˆ’π‘Ÿ)(1+πœ‰)π‘Ÿ(πœƒ+𝑑)πœ†(π‘Ÿ+π‘›βˆ’1)βˆ’1πœƒβˆ’πœ†π‘Ÿ[1βˆ’(1+ 𝑑 πœƒ ) βˆ’πœ† ] π‘Ÿβˆ’1 [(1+πœ‰)πœƒβˆ’πœ†βˆ’(πœƒ+𝑑)βˆ’πœ†] 𝑛+1 ( 18) where, π‘š = 𝑛! (π‘Ÿβˆ’1)!(π‘›βˆ’π‘Ÿ)! The pdf for first order statistics of MOLD, when the value of r is 1, and given by π‘ž(1)(𝑑) = π‘›πœ†πœ‰π‘›(1+πœ‰)(πœƒ+𝑑)βˆ’(πœ†π‘›+1)πœƒβˆ’πœ† [(1+πœ‰)πœƒβˆ’πœ†βˆ’(πœƒ+𝑑)βˆ’πœ†] 𝑛+1 ( 19) The pdf of nth order statistics of the MOLD when the value of r is n, and is given by π‘ž(𝑛)(𝑑) = π‘›πœ†πœ‰(1+πœ‰)𝑛(πœƒ+𝑑)βˆ’(πœ†+1)πœƒβˆ’πœ†π‘›[1βˆ’(1+ 𝑑 πœƒ ) βˆ’πœ† ] π‘›βˆ’1 [(1+πœ‰)πœƒβˆ’πœ†βˆ’(πœƒ+𝑑)βˆ’πœ†] 𝑛+1 ( 20) Communications on Applied Nonlinear Analysis ISSN: 1074-133X Vol 32 No. 10s (2025) 3553 https://internationalpubls.com 4.4 Stress-Strength Reliability The reliability model based on stress-strength analysis is expressed as R = P(X > Y), where X denotes the random strength capacity of a system or its component, while Y represents the random stress applied to the system or component at any given moment. In this study, we compute the stress-strength reliability by assuming that the stress Y follows an exponential distribution and the strength X follows a MOLD distribution. The rationale for modeling Y with an exponential distribution is that in many practical engineering scenarios, stress tends to grow exponentially over time. Let 𝑋 ∼ 𝑀𝑂𝐿𝐷(ΞΎ1, Ξ», ΞΈ) and π‘Œ ∼ 𝑀𝑂𝐿𝐷(ΞΎ2, Ξ», ΞΈ) with the pdf and cdf function given in Eq. (5) and (6) respectively. Hence 𝑅 = 𝑃(𝑋 > π‘Œ) 𝑅 = ∫ 𝑃 ∞ 0 (𝑋 > π‘Œ)𝑓(π‘₯)𝑑π‘₯ 𝑅 = ∫ (1 + ΞΎ2)[ΞΈβˆ’Ξ» βˆ’ (ΞΈ + π‘₯)βˆ’Ξ»] [(1 + ΞΎ2)ΞΈβˆ’Ξ» βˆ’ (ΞΈ + π‘₯)βˆ’Ξ»] ∞ 0 . ΞΎ1(1 + ΞΎ1)Ξ»ΞΈβˆ’Ξ»(ΞΈ + π‘₯)βˆ’(Ξ»+1) [(1 + ΞΎ1)ΞΈβˆ’Ξ» βˆ’ (ΞΈ + π‘₯)βˆ’Ξ»]2 𝑑π‘₯ Putting two substitutions in sequence, u = (ΞΈ + x)βˆ’Ξ» and 𝑣 = 𝑒/ΞΈβˆ’Ξ», we get 𝑅 = ΞΎ1(1 + ΞΎ1)(1 + ΞΎ2) ∫ (1 βˆ’ 𝑣) [(1 + ΞΎ1) βˆ’ 𝑣]2[(1 + ΞΎ2) βˆ’ 𝑣] 𝑑𝑣 1 0 After using By-Part method from calculus, we get 𝑅 = πœ‰1(1+πœ‰2) (πœ‰1βˆ’πœ‰2) + πœ‰1πœ‰2(1+πœ‰1)(1+πœ‰2)) (πœ‰1βˆ’πœ‰2)2 π‘™π‘œπ‘” ([ (1+πœ‰1)πœ‰2 (1+πœ‰2)πœ‰1 ]) ( 21) 6. Parameter Estimation 6.1 Classical estimation procedure The method of maximum likelihood estimation (MLE) is a key classical statistical methodology for the inference of parameters of probability distributions. The method operates by identifying the set of parameters which maximizes the value of the likelihood function, which is defined as the probability of the observed data under a specified model. For a series of i.i.d. observations t1, t2, … , tn constituting a sample of size n from the MOLD (ΞΎ, Ξ», ΞΈ) distribution, we can write the likelihood function as: 𝐿 (𝑑, πœ‰, πœ†, πœƒ) = πœ‰π‘›πœ†π‘›πœƒβˆ’π‘›πœ†(1 + πœ‰)𝑛 ∏ (πœƒ+𝑑𝑖)βˆ’(πœ†+1)𝑛 𝑖=1 ∏ [(1+πœ‰)πœƒβˆ’πœ†βˆ’(πœƒ+𝑑𝑖)βˆ’πœ†] 2𝑛 𝑖=1 ( 22) Using the Eq. (22) the log-likelihood function is given as log(𝐿) = 𝑛 log(ΞΎ) + 𝑛 log(Ξ») βˆ’ (Ξ» + 1) βˆ‘ log(ΞΈ + 𝑑𝑖) 𝑛 𝑖=1 βˆ’ 𝑛λ log(ΞΈ) +𝑛 π‘™π‘œπ‘”(1 + πœ‰) βˆ’ 2 βˆ‘ π‘™π‘œπ‘” ((1 + πœ‰)πœƒβˆ’πœ† βˆ’ (πœƒ + 𝑑𝑖) βˆ’πœ†)𝑛 𝑖=1 ( 23) Communications on Applied Nonlinear Analysis ISSN: 1074-133X Vol 32 No. 10s (2025) 3554 https://internationalpubls.com By partially differentiating log likelihood in Eq. (23) with respect to each parameter, we get the following closed form equations for the MLE for the parameters ΞΎ, Ξ» and ΞΈ, respectively as πœ• π‘™π‘œπ‘”(𝐿) πœ•πœ‰ = 𝑛 πœ‰ + 𝑛 (1+πœ‰) βˆ’ 2 βˆ‘ πœƒβˆ’πœ† (1+πœ‰)πœƒβˆ’πœ†βˆ’(πœƒ+𝑑𝑖)βˆ’πœ† 𝑛 𝑖=1 ( 24) πœ• π‘™π‘œπ‘”(𝐿) πœ•πœ† = 𝑛 πœ† βˆ’ 𝑛 π‘™π‘œπ‘”(πœƒ) βˆ’ βˆ‘ π‘™π‘œπ‘”(πœƒ + 𝑑𝑖) 𝑛 𝑖=1 + 2 βˆ‘ (1+πœ‰)πœƒβˆ’πœ† π‘™π‘œπ‘”(πœƒ)βˆ’(πœƒ+𝑑𝑖)βˆ’πœ† π‘™π‘œπ‘”(πœƒ+𝑑𝑖) (1+πœ‰)πœƒβˆ’πœ†βˆ’(πœƒ+𝑑𝑖)βˆ’πœ† 𝑛 𝑖=1 ( 25) πœ• π‘™π‘œπ‘”(𝐿) πœ•πœƒ = βˆ’π‘›πœ† πœƒ βˆ’ (πœ†+1) πœƒ βˆ‘ 1 1+𝑑𝑖/πœƒ 𝑛 𝑖=1 + 2 βˆ‘ πœ†(1+πœ‰)πœƒβˆ’(πœ†+1)βˆ’πœ†(πœƒ+𝑑𝑖)βˆ’(πœ†+1) (1+πœ‰)πœƒβˆ’πœ†βˆ’(πœƒ+𝑑𝑖)βˆ’πœ† 𝑛 𝑖=1 ( 26) The above non-linear equations cannot be solved analytically so, the MLE of the parameters ΞΎ, Ξ» and ΞΈ can be obtained as the numerical solution of the Eq. (24), (25) and (26), respectively. 6.2 Bayesian estimation In this section we used Bayesian parameter estimation methods for the Modi-Lomax distribution's parameters. Bayesian inference demands appropriate prior distribution selection to incorporate available information or parameter assumptions. Here, we employ gamma prior distributions for estimating parameters, which are suitable due to positive parameter space restrictions. The parameters are assumed to be independent and have gamma prior distributions such that ΞΎ ∼ Gamma(a1, b1) , Ξ» ∼ Gamma(a2, b2) and ΞΈ ∼ Gamma(a3, b3). Hence the joint prior density of ΞΎ, Ξ» and ΞΈ is given by πœ“(πœ‰, πœ†, πœƒ) ∝ πœ‰π‘Ž1βˆ’1π‘’βˆ’π‘1πœ‰πœ†π‘Ž2βˆ’1π‘’βˆ’π‘2πœ†πœƒπ‘Ž3βˆ’1π‘’βˆ’π‘3πœƒ ( 27) Where a1, b1, a2, b2, a3 and b3 are the hyper parameters. The hyper-parameters in the prior distributions are assumed to be known. The choice of loss function is pivotal in Bayesian decision theory, as it quantifies the penalty for estimation errors. Here, we adopt the squared error loss function (SELF), defined as: 𝐿𝑠(Ξ±, Ξ±Μ‚) = (Ξ±, Ξ±Μ‚)2 where Ξ± is the true parameter and Ξ±Μ‚ is its estimator. The SELF is symmetric and penalizes over and under estimation equally, yielding the posterior mean as the optimal estimator. This approach balances computational tractability with theoretical rigor, making it widely used in reliability and survival analysis. By employing the likelihood function in Eq. (22) with the joint prior distribution in Eq. (28), the joint posterior distribution of ΞΎ, Ξ» and ΞΈ can be expressed in the following form: Ο€(ΞΎ, Ξ», ΞΈ) ∝ ΞΎπ‘Ž1+π‘›βˆ’1Ξ»π‘Ž2+π‘›βˆ’1ΞΈπ‘Ž3βˆ’π‘›Ξ»βˆ’1π‘’βˆ’π‘1ΞΎβˆ’π‘2Ξ»βˆ’π‘3ΞΈ(1 + ΞΎ)𝑛 ∏ (πœƒ+𝑑𝑖)βˆ’(πœ†+1)𝑛 𝑖=1 ∏ [(1+πœ‰)πœƒβˆ’πœ†βˆ’(πœƒ+𝑑𝑖)βˆ’πœ†] 2𝑛 𝑖=1 ( 28) Communications on Applied Nonlinear Analysis ISSN: 1074-133X Vol 32 No. 10s (2025) 3555 https://internationalpubls.com The Bayes estimators under the SELF loss function is the posterior mean of the posterior distribution, are given as, ΞΎΜ‚ = 1 Ξ΄ ∫ ∫ βˆ«ΞΎπ‘Ž1+𝑛 θλξ Ξ»π‘Ž2+π‘›βˆ’1ΞΈπ‘Ž3βˆ’π‘›Ξ»βˆ’1π‘’βˆ’π‘1ΞΎβˆ’π‘2Ξ»βˆ’π‘3ΞΈ(1 + ΞΎ)𝑛 ∏ (πœƒ+𝑑𝑖)βˆ’(πœ†+1)𝑛 𝑖=1 ∏ [(1+πœ‰)πœƒβˆ’πœ†βˆ’(πœƒ+𝑑𝑖)βˆ’πœ†] 2𝑛 𝑖=1 β€‰π‘‘πœ‰β€‰π‘‘πœ†β€‰π‘‘ ( 29) Ξ»Μ‚ = 1 Ξ΄ ∫ ∫ βˆ«ΞΎπ‘Ž1+π‘›βˆ’1 θλξ Ξ»π‘Ž2+π‘›ΞΈπ‘Ž3βˆ’π‘›Ξ»βˆ’1π‘’βˆ’π‘1ΞΎβˆ’π‘2Ξ»βˆ’π‘3ΞΈ(1 + ΞΎ)𝑛 ∏ (πœƒ+𝑑𝑖)βˆ’(πœ†+1)𝑛 𝑖=1 ∏ [(1+πœ‰)πœƒβˆ’πœ†βˆ’(πœƒ+𝑑𝑖)βˆ’πœ†] 2𝑛 𝑖=1 β€‰π‘‘πœ‰β€‰π‘‘πœ†β€‰π‘‘ ( 30) and ΞΈΜ‚ = 1 Ξ΄ ∫ ∫ βˆ«ΞΎπ‘Ž1+π‘›βˆ’1 θλξ Ξ»π‘Ž2+π‘›βˆ’1ΞΈπ‘Ž3βˆ’π‘›Ξ»π‘’βˆ’π‘1ΞΎβˆ’π‘2Ξ»βˆ’π‘3ΞΈ(1 + ΞΎ)𝑛 ∏ (πœƒ+𝑑𝑖)βˆ’(πœ†+1)𝑛 𝑖=1 ∏ [(1+πœ‰)πœƒβˆ’πœ†βˆ’(πœƒ+𝑑𝑖)βˆ’πœ†] 2𝑛 𝑖=1 β€‰π‘‘πœ‰β€‰π‘‘πœ†β€‰π‘‘ ( 31) respectively, where Ξ΄ = ∫ ∫ βˆ«ΞΎπ‘Ž1+π‘›βˆ’1 θλξ Ξ»π‘Ž2+π‘›βˆ’1ΞΈπ‘Ž3βˆ’π‘›Ξ»βˆ’1π‘’βˆ’π‘1ΞΎβˆ’π‘2Ξ»βˆ’π‘3ΞΈ(1 + ΞΎ)𝑛 ∏ (πœƒ+𝑑𝑖)βˆ’(πœ†+1)𝑛 𝑖=1 ∏ [(1+πœ‰)πœƒβˆ’πœ†βˆ’(πœƒ+𝑑𝑖)βˆ’πœ†] 2𝑛 𝑖=1 β€‰π‘‘πœ‰β€‰π‘‘πœ†β€‰π‘‘ The mathematical intricacy of posterior expectations from mathematically formulated expressions inherently renders it difficult to obtain closed-form analytical solutions. To avoid this computational hurdle, researchers can utilize a number of Bayesian approximation techniques, including Lindley's approximation, Tierney-Kadane's method, or Markov Chain Monte Carlo (MCMC) techniques. In our study, we use MCMC sampling to approximate the posterior expectations, as described in the next section. 6.3 Markov Chain Monte Carlo (MCMC) method We must first determine the complete conditional distributions of the ΞΎ, Ξ», and ΞΈ in order to apply the MCMC approach, as indicated below. πœ‹βˆ—(πœ‰|πœ†, πœƒ, π‘‘π‘Žπ‘‘π‘Ž) ∝ πœ‰π‘Ž1+π‘›βˆ’1π‘’βˆ’π‘1πœ‰(1 + πœ‰)𝑛 1 ∏ [(1+πœ‰)πœƒβˆ’πœ†βˆ’(πœƒ+𝑑𝑖)βˆ’πœ†] 2𝑛 𝑖=1 ( 32) πœ‹βˆ—(πœ†|πœ‰, πœƒ, π‘‘π‘Žπ‘‘π‘Ž) ∝ πœ†π‘Ž2+π‘›βˆ’1πœƒβˆ’π‘›πœ†π‘’βˆ’π‘2πœ† ∏ (πœƒ+𝑑𝑖)βˆ’(πœ†+1)𝑛 𝑖=1 ∏ [(1+πœ‰)πœƒβˆ’πœ†βˆ’(πœƒ+𝑑𝑖)βˆ’πœ†] 2𝑛 𝑖=1 ( 33) and Communications on Applied Nonlinear Analysis ISSN: 1074-133X Vol 32 No. 10s (2025) 3556 https://internationalpubls.com πœ‹βˆ—(πœƒ|πœ‰, πœ†, π‘‘π‘Žπ‘‘π‘Ž) ∝ πœƒπ‘Ž3βˆ’π‘›πœ†βˆ’1π‘’βˆ’π‘3πœƒ ∏ (πœƒ+𝑑𝑖)βˆ’(πœ†+1)𝑛 𝑖=1 ∏ [(1+πœ‰)πœƒβˆ’πœ†βˆ’(πœƒ+𝑑𝑖)βˆ’πœ†] 2𝑛 𝑖=1 ( 34) The conditional posterior distributions in Eq. (32), (33) and (34) of the parameters under the Bayesian framework do not follow any standard or closed-form distribution. This non-standard nature arises due to the complexity of our likelihood function combined with the Gamma prior distributions, which prevents the use of direct sampling methods. As a result, conventional analytical approaches become impractical. To address this, the Metropolis-Hastings (MH) algorithm is employed as a flexible and efficient Markov Chain Monte Carlo (MCMC) technique to generate samples from the intractable conditional distributions and obtain the Bayesian estimates of the parameters. MH algorithm is carried out in following steps: 1. Set the starting value ΞΎ(0) = ΞΎΜ‚, Ξ»(0) = Ξ»Μ‚ and ΞΈ(0) = ΞΈΜ‚ through MLE. 2. Set 𝑖 = 1. 3. Create xiβˆ—, Ξ»βˆ— and ΞΈβˆ— from N(ΞΎΜ‚, Οƒ2 ΞΎΜ‚), N(Ξ»Μ‚, Οƒ2 Ξ»Μ‚) and N(ΞΈΜ‚, Οƒ2 ΞΈΜ‚), respectively. 4. Find π΄πœ‰ ,AΞ» and Aπœƒ as 𝐴ξ = π‘šπ‘–π‘› {1, Ο€βˆ—(ΞΎβˆ—|Ξ»(π‘–βˆ’1), ΞΈ(π‘–βˆ’1), π‘‘π‘Žπ‘‘π‘Ž) Ο€βˆ—(ΞΎ(π‘–βˆ’1)|Ξ»(π‘–βˆ’1), ΞΈ(π‘–βˆ’1), π‘‘π‘Žπ‘‘π‘Ž) }, 𝐴λ = π‘šπ‘–π‘› {1, Ο€βˆ—(Ξ»βˆ—|ΞΎ(π‘–βˆ’1), ΞΈ(π‘–βˆ’1), π‘‘π‘Žπ‘‘π‘Ž) Ο€βˆ—(Ξ»(π‘–βˆ’1)|ΞΎ(π‘–βˆ’1), ΞΈ(π‘–βˆ’1), π‘‘π‘Žπ‘‘π‘Ž) } and 𝐴θ = π‘šπ‘–π‘› {1, Ο€βˆ—(ΞΈβˆ—|ΞΎ(π‘–βˆ’1), Ξ»(π‘–βˆ’1), π‘‘π‘Žπ‘‘π‘Ž) Ο€βˆ—(ΞΈ(π‘–βˆ’1)|ΞΎ(π‘–βˆ’1), Ξ»(π‘–βˆ’1), π‘‘π‘Žπ‘‘π‘Ž) } 5. Utilizing the uniform U (0,1) distribution, generate samples u1, u2 and u3 respectively for ΞΎ, Ξ» and ΞΈ. 6. If u1, u2 and u3 are less than AΞΎ, AΞ» and AΞΈ, respectively than set ΞΎ(i) = ΞΎβˆ—, Ξ»(i) = Ξ»βˆ— and ΞΈ(i) = ΞΈβˆ—, respectively. Otherwise, set ΞΎ(i) = ΞΎiβˆ’1, Ξ»(i) = Ξ»iβˆ’1 and ΞΈ(i) = ΞΈiβˆ’1, respectively. 7. Set i = i + 1 8. Redo steps 3 - 7, L times to get ΞΎ(i), Ξ»(i) and ΞΈ(i)for i = 1,2, βˆ’ βˆ’ βˆ’, L. 9. After a suitable burn-in phase, say D, obtain the Bayes estimate of the parameter ΞΎ, Ξ» and ΞΈ as an example, as ΞΎΜƒ = 1 𝐿 βˆ’ 𝐷 βˆ‘ ΞΎ(𝑖) 𝐿 𝑖=𝐷+1 , Ξ»Μƒ = 1 𝐿 βˆ’ 𝐷 βˆ‘ Ξ»(𝑖) 𝐿 𝑖=𝐷+1 , ΞΈΜƒ = 1 𝐿 βˆ’ 𝐷 βˆ‘ ΞΈ(𝑖) 𝐿 𝑖=𝐷+1 . Communications on Applied Nonlinear Analysis ISSN: 1074-133X Vol 32 No. 10s (2025) 3557 https://internationalpubls.com 7. Simulation Study In this section, to determine the effectiveness of MOLD estimators, we conduct a Monte Carlo simulation. Using specific selected variable values and the MOLD distribution, a number of random numbers are generated. The following procedures to investigate the new model are now presented: [Step:1] Fix the values of MOLD (ΞΎ, Ξ», ΞΈ) as Set-1 MOLD (9, 5, 0.25) and Set-2 MOLD (0.02, 0.05, 10). [Step:2] Fix the sample sizes n as n = 10, 30, 50, 200. [Step:3] Fix the number of replications as 1000. [Step:4] Generate the random samples using Quantile function given in Eq. (13). π‘₯𝑖 = ΞΈ [( 1 + ΞΎ βˆ’ 𝑒𝑖 (1 + ΞΎ)(1 βˆ’ 𝑒𝑖) ) 1/Ξ» βˆ’ 1] ,where 𝑒𝑖 ∼ π‘ˆ(0,1), 𝑖 = 1,2, … , 𝑛. [Step:5] The MLE of each parameter are obtained using the optim function in R software using the log-likelihood function from Eq. (23). [Step:6] Bayes estimates of the parameters are obtained based on two informative prior sets as Prior-1 (P-1) (a1, a2, a4) = (18,10,0.5) and bi = 2 for i = 1, 2, 3. Prior-2 (P-2) (a1, a2, a4) = (0.08,0.20,40) and bi = 4 for i = 1, 2, 3. [Step:7] The performance of the point estimates is assessed using two criteria: mean squared error (MSE) and absolute bias (AB). 𝑀𝑆𝐸 = 1 𝑁 βˆ‘(ΞΈΜ‚ βˆ’ ΞΈ) 2 𝑁 𝑖=1 𝐴𝐡 = |(πœƒ βˆ’ ΞΈ)| where, ΞΈ= Parameter true value, ΞΈΜ‚ = Estimated value of the parameter. Table 1: Mean Estimate, Absolute Bias (AB) and Mean Squared Error (MSE) of the parameters of MOLD under MLE and Bayesian Method (BM) for Case-1 𝑛 Properties MLE BM ΞΎ = 9 Ξ» = 5 πœƒ = 0.25 ΞΎ = 9 Ξ» = 5 πœƒ = 0.25 Mean Estimate 8.35711 7.12690 0.26704 8.96335 4.97687 0.25111 10 AB 0.64289 2.12690 0.01704 0.03665 0.02313 0.00111 MSE 10.91290 16.11558 0.01407 0.34820 0.50040 0.00636 Mean Estimate 8.33814 7.05030 0.25669 9.08599 4.98748 0.25240 30 AB 0.66187 2.05030 0.00669 0.08599 0.01252 0.00240 Communications on Applied Nonlinear Analysis ISSN: 1074-133X Vol 32 No. 10s (2025) 3558 https://internationalpubls.com MSE 9.48808 12.27414 0.00397 0.55615 0.50785 0.00424 Mean Estimate 8.20359 6.85089 0.25723 9.04125 5.11707 0.25892 50 AB 0.79641 1.85089 0.00723 0.04125 0.11707 0.00892 MSE 9.52439 9.91493 0.00253 0.42477 0.64209 0.00343 Mean Estimate 8.81283 6.18065 0.25527 9.02399 5.00547 0.25215 200 AB 0.18717 1.18065 0.00527 0.02399 0.00547 0.00215 MSE 3.23149 3.64873 0.00051 0.74400 0.69949 0.00272 Table 2: Mean Estimate, Absolute Bias (AB) and Mean Squared Error (MSE) of the parameters of MOLD under MLE and Bayesian method (BM) for Case-2 𝑛 Properties MLE BM ΞΎ = 0.02 Ξ» = 0.05 πœƒ = 10 ΞΎ = 0.02 Ξ» = 0.05 πœƒ = 10 Mean Estimate 0.09588 0.02575 9.99064 0.05352 0.09236 10.04951 10 AB 0.07588 0.02425 0.00936 0.03352 0.04236 0.04951 MSE 0.01284 0.00188 0.08164 0.00241 0.00580 2.46946 Mean Estimate 0.06400 0.03510 9.99969 0.05335 0.10310 9.92382 30 AB 0.04400 0.01490 0.00031 0.03335 0.05310 0.07618 MSE 0.00439 0.00141 0.00000 0.00344 0.01054 2.12657 Mean Estimate 0.05590 0.03890 9.99959 0.05349 0.09945 9.82858 50 AB 0.03590 0.01110 0.00041 0.03349 0.04945 0.17142 MSE 0.00321 0.00128 0.00001 0.00476 0.01133 1.42323 Mean Estimate 0.02828 0.05120 9.97097 0.02491 0.05684 9.84556 200 AB 0.00828 0.00120 0.02904 0.00491 0.00684 0.15444 MSE 0.00063 0.00071 0.10122 0.00038 0.00140 0.43880 Tables (1) and (2) present the parameter estimates for the MOLD distribution obtained through maximum likelihood estimation and Bayesian methodology, respectively. A comparative analysis of the results indicates that the Bayesian approach yields superior parameter estimates relative to the maximum likelihood method, consistent with findings reported in the existing literature. 8. Application To demonstrate the practical applicability of the proposed MOLD distribution, we analyse a medical dataset comprising remission times (measured in months) for 137 bladder cancer patients. This dataset Table (3), originally reported by (Lee & Wang, 2003), provides survival times that exhibit the characteristics commonly observed in oncological studies. The observed remission times range from 0.08 to 79.05 months, with the complete dataset presented as follows: Table 3: Remission time (in month) of 137 cancer patients 4.5 32.15 3.88 13.8 19.13 4.87 3.02 5.85 14.24 5.71 19.36 7.09 7.87 7.59 20.28 5.32 5.49 3.02 46.12 4.33 2.02 4.51 5.17 2.83 9.22 1.05 0.2 8.37 3.82 9.47 36.66 14.77 26.31 79.05 10.06 8.53 4.65 2.02 4.98 11.98 2.62 4.26 5.06 1.76 0.9 11.25 16.62 4.4 21.73 10.34 12.07 34.26 0.87 10.66 6.97 2.07 0.51 12.03 0.08 17.12 Communications on Applied Nonlinear Analysis ISSN: 1074-133X Vol 32 No. 10s (2025) 3559 https://internationalpubls.com 3.36 2.64 1.4 12.63 43.01 14.76 2.75 7.66 0.81 1.19 7.32 4.18 3.36 8.66 1.26 13.29 1.46 14.83 6.76 23.63 24.8 5.62 8.6 3.25 10.86 18.1 7.62 7.63 17.14 25.74 3.52 2.87 15.96 17.36 9.74 3.31 7.28 1.35 0.4 2.26 4.33 9.02 5.41 2.69 22.69 6.94 2.54 11.79 2.46 7.26 2.69 5.34 3.48 4.7 8.26 6.93 4.23 3.7 0.5 10.75 6.54 3.64 5.32 13.11 8.65 3.57 5.09 7.39 5.41 11.64 2.09 2.23 6.25 7.93 4.34 25.82 12.02 We applied MLE and Bayesian method to fit the MOLD parameters and conducted a comparative study against seven competing distributions from the Lomax family. The comparative models included Log-Lomax (LoL) by (Ishaq et al., 2025), Power Lomax (PoL) by (Rady et al., 2016), Rayleigh Lomax (RaL) by (Shabbir et al., 2018), Power X-Lindey (PXLin) by (Elgarhy et al., 2025), Poisson Inverted Lomax (PoIL) by (Joshi & Kumar, 2021), Exponentiated odd Lomax exponential distribution (EOLE) by (Dhungana & Kumar, 2022) and Transmuted Exponential Lomax (TEL) by (Ashour & Eltehiwy, 2013). Distribution comparison is performed using a comprehensive set of information criteria, specifically AIC, BIC, CAIC, and HQIC, representing the Akaike, Bayesian, Consistent Akaike, and Hannan-Quinn information criteria, respectively. We also used the Kolmogorov-Smirnov (K-S) test to better check how well each distribution worked. We picked the best distribution by looking for the one with the highest log-likelihood value, the best p-value from the K-S test, and the lowest AIC, BIC, and CAIC scores. Table 4: Goodness of fit tests for cancer patient dataset Distributions -2logL AIC BIC HQIC CAIC K-S p-value MOLDx 885.4448 891.4448 900.2047 895.0046 891.6253 0.17 0.000726 RaL 885.8124 891.8124 900.5723 895.3722 891.9929 0.1961 5.33e-05 LoL 888.3446 894.3446 903.1045 897.9044 894.5251 0.2103 1.09e-05 PXLin 912.2588 918.2588 927.0187 921.8186 918.4393 0.2052 1.94e-05 PoIL 989.5734 995.5734 1004.333 999.1332 995.7539 0.3391 4.18e-14 EOLE 997.8764 997.5734 997.5734 1009.253 1002.32 0.1955 5.64e-05 TEL 1017.408 1025.408 1037.087 1030.154 1025.711 0.3384 4.72e-14 PoL 1111.972 1117.972 1126.732 1121.531 1118.152 0.2587 2.17e-08 Table (4) presents a comparative analysis of the MOLD against seven alternative distribution functions using goodness-of-fit measures. The results demonstrate that MOLD exhibits superior performance, achieving the minimum values for AIC, BIC, HQIC, and CAIC relative to the seven competing distributions. Additionally, we computed the Kolmogorov Smirnov test statistic alongside its associated p-value. Optimal model fit is characterized by minimal K-S values and maximal p-values. The MOLD yielded a K-S statistic of 0.17 with a corresponding p-value of 0.000726, representing the most favourable performance among all competing models, thereby establishing MOLD as the most appropriate distribution for practical applications, particularly in modelling cancer patient remission times. Communications on Applied Nonlinear Analysis ISSN: 1074-133X Vol 32 No. 10s (2025) 3560 https://internationalpubls.com Figure 5. Plots for the Cancer patient’s dataset Figure (5) displays three visual diagnostic toolsβ€”probability density function histogram, empirical cumulative distribution function (ECDF), and probability-probability plot utilized to assess model adequacy across various distributions for the given dataset. Throughout all three evaluation methods, MOLD exhibits optimal fitting characteristics, as evidenced by its curves closely following the observed data patterns. The newly developed MOLD distribution achieved superior performance when compared to existing competitive models, showing better goodness-of-fit measures and diminished information criteria scores. These empirical outcomes emphasize its capability in modelling non-symmetric and sophisticated data configurations. The findings of this investigation present the MOLD as a significant analytical resource for reliability engineering, survival research, and risk management applications. 9. Conclusion This research introduces the MOLD, a new three-parameter extension of the standard Lomax distribution, created to overcome challenges in studying complex survival and reliability data. The distribution features heavy tails and a decreasing hazard rate, making it suitable for long-term survival analysis. By combining the flexible properties of the Modi family with the basic structure of the Lomax distribution, the MOLD shows improved adaptability through its hazard function behaviour, quantile features, and tail properties. We developed a complete mathematical framework for the distribution, including moments, survival functions, and entropy measures, which confirms its theoretical strength. For parameter estimation, we applied both classical maximum likelihood estimation (MLE) and Bayesian methods using gamma priors. Monte Carlo simulations validated that the MLE estimators are consistent and asymptotically efficient. Our simulation studies examined estimator performance using mean squared error, showing that estimation accuracy improves as sample sizes increase. To test practical usefulness, we applied the MOLD to a bladder cancer patient dataset and compared it with existing distributions using standard measures like AIC, BIC, CAIC, log-likelihood, and the Kolmogorov-Smirnov test. The MOLD consistently performed better than competing models, showing superior fit quality and lower information criteria values. These results demonstrate its effectiveness in modelling skewed and complex data patterns. Communications on Applied Nonlinear Analysis ISSN: 1074-133X Vol 32 No. 10s (2025) 3561 https://internationalpubls.com The study establishes the MOLD as a useful tool for reliability analysis, survival studies, and risk assessment, particularly when dealing with heavy-tailed data that exhibits decreasing failure rates over time. 10. Future Scope Future work could develop the MOLD for multiple variables and use Bayesian approaches for complicated data analysis. Researchers could also improve how it handles incomplete data and combine it with artificial intelligence for better predictions. Testing the MOLD against newer statistical models and adapting it for specific fields like weather studies or smart device networks would show how widely it can be used and help advance survival analysis and risk assessment. References [1] Ahsanullah, M. (1991). β€œRecord values of the Lomax distribution”. Statistica Neerlandica, 45(1), 21–29. [2] Arnold, B. C. (1983). Pareto Distribution. John Wiley & Sons, Ltd. [3] Ashour, S. K., & Eltehiwy, M. A. (2013). β€œTransmuted exponentiated Lomax distribution”. Australian Journal of Basic and Applied Sciences, 7(7), 658–667. [4] Atkinson, A. B., & Harrison, A. J. (1978). Distribution of personal wealth in Britain. Cambridge, UK: Cambridge University Press. [5] Balakrishnan, N., & Ahsanullah, M. (1994). β€œRelations for single and product moments of record values from Lomax distribution”. Sankhyā: The Indian Journal of Statistics, Series B, 140–146. [6] Balkema, A. A., & De Haan, L. (1974). β€œResidual life time at great age”. The Annals of Probability, 2(5), 792–804. [7] Bryson, M. C. (1974). β€œHeavy-tailed distributions: properties and tests”. Technometrics, 16(1), 61–68. [8] Chahkandi, M., Farsi, M., & Ganjali, M. (2009). β€œOn the renewal function of Poisson shock models with Lomax distribution as the time between the shocks”. Journal of the Iranian Statistical Society, 8(1–2), 63– 75. [9] Dhungana, G. P., & Kumar, V. (2022). β€œExponentiated Odd Lomax Exponential distribution with application to COVID-19 death cases of Nepal”. PloS One, 17(6), e0269450. [10] Elgarhy, M., Hassan, A. S., Alsadat, N., Balogun, O. S., Shawki, A. W., & Ragab, I. E. (2025). β€œA Heavy Tailed Model Based on Power XLindley Distribution with Actuarial Data Applications”. Computer Modeling in Engineering & Sciences (CMES), 142(3). [11] Harris, C. M. (1968). β€œThe Pareto distribution as a queue service discipline”. Operations Research, 16(2), 307–313. [12] Ishaq, A. I., Usman, A. U., Alqifari, H. N., Almohaimeed, A., Daud, H., Abba, S. I., & Suleiman, A. A. (2025). β€œA new Log-Lomax distribution, properties, stock price, and heart attack predictions using machine learning techniques”. AIMS Mathematics, 10(5), 12761–12807. [13] Johnson, N. L., Kotz, S., & Balakrishnan, N. (1994). Continuous univariate distributions, volume 2 (Vol. 2). John Wiley & Sons. [14] Joshi, R. K., & Kumar, V. (2021). β€œPoisson inverted Lomax distribution: Properties and applications”. International Journal of Research in Engineering and Science (IJRES), 9(1), 48–57. Communications on Applied Nonlinear Analysis ISSN: 1074-133X Vol 32 No. 10s (2025) 3562 https://internationalpubls.com [15] Kumar, S., Meena, B., Shukla, R., & Singh, S. P. (2025). β€œModi rayleigh distribution and its application to survival time data sets”. Life Cycle Reliability and Safety Engineering, 1–10. [16] Kumawat, H., Modi, K., & Nagar, P. (2024). β€œModi-Weibull Distribution: Inferential and Simulation Study”. Journal Annals of Data Science, 11(06), 1975–1999. [17] Lee, E. T., & Wang, J. (2003). Statistical methods for survival data analysis (Vol. 476). John Wiley & Sons. [18] Modi, K., Kumar, D., & Singh, Y. (2020). β€œA new family of distribution with application on two real datasets on survival problem”. Journal Science & Technology Asia, 1–10. [19] Ndayisaba, A. D., Odongo, L. O., & Ngunyi, A. (2023). β€œThe Modi Exponentiated Exponential Distribution”. J Mod Appl Stat Methods, 11, 341–-359. [20] Rady, E.-H. A., Hassanein, W. A., & Elhaddad, T. A. (2016). β€œThe power Lomax distribution with an application to bladder cancer data”. SpringerPlus, 5(1), 1838. [21] Shabbir, M., Riaz, A., & Gull, H. (2018). β€œRayleigh Lomax distribution”. The Journal of Middle East and North Africa Sciences, 4(12), 1–4. [22] Tadikamalla, P. R. (1980). β€œA look at the Burr and related distributions”. International Statistical Review/Revue Internationale de Statistique, 337–344.