Development and validation of a task load index for process control room operators (PCRO-TLX)

Area of Science:

• Human Factors
• Occupational Health
• Cognitive Psychology

Background:

• Process control room operators (PCRO) manage complex, safety-critical tasks.
• Existing workload assessment tools may not fully capture the nuances of PCRO roles.
• Developing an occupation-specific tool is crucial for accurate workload measurement.

Purpose of the Study:

• To develop and validate an occupation-specific tool for measuring the task load of PCROs.
• To adapt the NASA Task Load Index (TLX) methodology for the PCRO context.
• To ensure the tool has acceptable psychometric properties and relevance.

Main Methods:

• Exploratory sequential mixed methods study involving human factors experts and PCROs.
• Cognitive task analysis, literature review, and expert panels to define dimensions.
• Validation using data from 146 PCROs and comparison with NASA-TLX and Subjective Workload Assessment Technique (SWAT).

Main Results:

• Six dimensions for PCRO workload were identified: perceptual demand, performance, mental demand, time pressure, effort, and stress.
• The developed PCRO-TLX demonstrated acceptable psychometric properties (α = 0.83).
• Perceptual demand was found to be more relevant than physical demand for PCRO workload, with positive convergence with SWAT scores.

Conclusions:

• The PCRO-TLX is a reliable and valid tool for assessing the task load of process control room operators.
• This specialized tool can aid in risk assessment and optimize health and safety in critical operational environments.
• The findings highlight the importance of occupation-specific workload measurement in safety-critical roles.