Variability Of Quality Characteristics Research Articles

Loading time monitoring via individual control charts

In quality control we find techniques that come from different fields, because the objective is to reduce the variability in quality characteristics, these are control and adjustment of processes. In this work, the individual control charts (Xind and Rm) were used to monitor the loading time of a truck measured during 60 consecutive days of a cargo transport company in Rio Grande do Sul. The results showed that the process is out of control both in average and variability, requiring a systematic monitoring in order for the company to maintain the quality of services provided to its customers.

Willingness-to-Pay for Attribute Level and Variability: The Case of Mexican Millers' Demand for Hard Red Winter Wheat

In-person interviews were carried out with Mexican millers who were administered a conjoint-type survey designed to incorporate uncertainty in attribute levels. Two methods were used to model millers' risk preferences: a modified mean-variance approach and an explicit expected utility approach. Controlling for variability, Mexican millers are willing to pay premiums for increases in quality factors such as test weight, protein content, falling number, and dough strength/extensibility. We find millers are not particularly sensitive to changes in the variability of quality characteristics. Out-of-sample forecasts suggest the mean-variance model provides an accurate depiction of actual Mexican imports.