What is the normal distribution the FDOT expects for quality control purposes?

In the context of quality control processes, a normal distribution serves as a statistical model to represent the expected behavior of measured characteristics in a population. The FDOT establishes an acceptance limit of 95% within the specification limits to ensure a high degree of confidence in the quality of materials and workmanship on projects.

This 95% acceptance limit means that, statistically, 95% of the data points collected from a quality control measure will fall within the defined specification limits. This level of acceptance strikes a balance that allows for some variability in the manufacturing processes while still maintaining a standard that ensures that the majority of outputs meet the required quality thresholds.

Utilizing 95% acceptance limits helps mitigate risks associated with non-conformance, enhances safety, and promotes the long-term sustainability of infrastructure projects. It aligns with industry best practices, where a higher confidence interval is desirable to ascertain that the outputs meet the rigorous demands of public safety and structural integrity.

Thus, this standard reflects FDOT's commitment to rigorous quality assurance protocols, supporting the overall goal of maintaining high standards in construction and engineering efforts.