There are a number of bathtub and unimodal hazard shape parametric lifetime distributions available in the literature. Therefore, it is important to classify these distributions based on their hazard flexibility to facilitate their use in applications. For this purpose we use the Total Time on Test (TTT) transform plot with two different criteria: I. measure the slope at the inflection point on the scaled TTT transform curve; II. measure the slope at selected points from the constant hazard line on the scaled TTT transform curve. We confine our research to classify the flexibility of Weibull extensions and generalizations and also select one-shape and two-shape parameter lifetime distributions to exemplify the two criteria process.

Author Bio

Dana Lacey is pursuing a Mathematics and Actuarial Science double major at North Central College (class of 2016). She is also in the Honors program and a mathematics tutor. She completed this research during the Central Michigan University REU program.

Anh Nguyen is majoring in Mathematics with Actuarial Concentration at Texas Christian University (class of 2016) with minors in Computer Science and Economics. She is in the Honors program and also works as a research assistant in Economics department. She completed this research during the REU in Central Michigan University.