The ISA Human-Machine Interface Standard
By Stephen LaMarca, Manufacturing Technology Analyst at AMT – The Association For Manufacturing Technology, which owns IMTS – The International Manufacturing Technology Show
The human-machine interface (HMI) is the crossing point between operators and modern manufacturing technology. The human machinist/operator depends on the HMI’s output to provide feedback on the physical process. It is the instrument operators use to adjust operating parameters. An HMI that is easy to understand and gives clear options to end users will produce fewer errors, increase operator productivity, and reduce stress. Improved HMI design can prevent significant losses to a business in terms of time and materials wasted.
The purpose of ISA101-HMI is to establish standards, recommended practices, and/or technical reports pertaining to HMIs in manufacturing applications. These will be directed to those responsible for designing, implementing, using, and/or managing HMIs. Unless noted otherwise in a specific ISA101 document, the documents will apply to all manufacturing industries.
Areas covered within the standard:
• menu hierarchies
• screen navigation conventions
• graphics and color conventions
• dynamic elements
• alarming conventions
• security methods and electronic signature attributes
• interfaces with background programming and historical databases
• popup conventions
• help screens and methods used to work with alarms
• program object interfaces
• configuration interfaces to databases, servers, and networks.
Additionally, ISA101-HMI defines the terminology and models to develop an HMI and the work processes recommended to effectively maintain it throughout its life cycle. Use of the standard should provide guidance to design, build, operate, and maintain effective HMIs that result in safer, more effective, and more efficient control of a given process. It is anticipated to also improve the user's ability to detect, diagnose, and appropriately respond to abnormal situations.
If the standard, recommended practices, and methodology are followed, the result should yield improved safety, quality, production, and reliability.