ISA recommended practice: HMI task analysis document approved

By Control Engineering Staff May 10, 2007

A new recommended practice for HMI task analysis has been approved by the

ISA (Instrumentation, Systems, and Automation Society

. ISA-RP77.60.65, “Fossil Fuel Power Plant Human-Machine Interface: Task Analysis” provides guidance and suggests an approach for conducting a task analysis as part of the design and development of new control rooms and systems for power plants and for supporting major control room upgrade programs. When task analysis data are collected early, says ISA, they are beneficial throughout the design process and serve to identify instrumentation needs, assist in evaluating design options, and in validating completed designs for HMI concerns.

The recommended practice is part of a three-part series on the topic. Other documents include: ISA-RP77.60.02-2000 (R2005), “Fossil Fuel Power Plant Human-Machine Interface—Alarms;” and ISA-TR77.60.04-1996 (R2004), “Fossil Fuel Power Plant Human-Machine Interface—Electronic Screen Displays”

The documents recommend task analysis approaches during the conceptual design, preliminary design, and detailed design phases, and also the test and evaluation of new control rooms and systems and control room upgrade and development programs. The relationship between task analysis and other system development techniques is considered; however, the emphasis, points out ISA, is on the methods and benefits derived from a detailed analysis of operator functions and activities in the control room.

Methods used to support the task analysis are also presented. These include the use of surveys and questionnaires, tabletop analysis approaches, and the use of mockups and walkthroughs. Applications of these data are considered for addressing a number of design-related issues.

The purpose of the ISA-SP77.60 committee’s work, according to ISA, is to provide human engineering guidance in the design of new control rooms and the upgrading of existing facilities. The primary application is for fossil power plants; however, the documents are general enough to be suitable for similar process industries.

—Edited by Jeanine Katzel , Control Engineering senior editor