Differences between Qualitative, Semi-quantitative, and Quantitative in risk-based inspection (RBI) studies


Qualitative RBI

Semi-Quantitative RBI

Quantitative RBI

Based on expert judgment and experience

Uses a combination of expert judgment and quantifiable data

Relies on quantifiable data and modeling techniques

Less detailed and more subjective

Provides more detail than qualitative RBI, but is still subjective

Objective and provides a detailed and quantifiable analysis

Used for preliminary assessments or when data is limited

Used when data is limited, but more information is needed

Used when detailed and accurate data is available

Typically less time-consuming and less expensive

More time-consuming and expensive than qualitative RBI

Most time-consuming and expensive of the three methods

Provides a general understanding of risk levels

Provides a more detailed understanding of risk levels

Provides a highly detailed and accurate understanding of risk levels

Not suitable for critical equipment or systems

Suitable for critical equipment or systems, but with limitations

Suitable for critical equipment or systems

Provides broad-based risk rankings

Provides more detailed and specific risk rankings

Provides the most detailed and accurate risk rankings

Typically used for screening and prioritization

Typically used for more detailed analysis and decision-making

Typically used for making informed decisions about inspection and maintenance activities

May not identify specific equipment or components at risk

Can identify specific equipment or components at risk, but with limitations

Identifies specific equipment or components at risk with high accuracy

Suitable for facilities with limited data

Suitable for facilities with moderate amounts of data

Suitable for facilities with extensive data

Can provide a high-level view of risk across a facility

Can provide a more detailed view of risk across a facility

Can provide the most detailed and accurate view of risk across a facility