This standard addresses Human Machine Interfaces for equipment and automated processes. If the standard, recommended practices and methodology are followed, the result should enable the users to be more effective yielding improved safety, quality, productivity and reliability. The recommendations in this document are applicable to any process using an HMI to interface to a control system, including but not limited to continuous, batch, and discrete processes. There may be differences in implementation to meet the specific needs based on process type. The purpose of this standard is to address the philosophy, design, implementation, operation, and maintenance of Human Machine Interfaces (HMIs) for process automation systems, including multiple work processes throughout the HMI lifecycle. It is also intended to help users to understand the basic concepts as a way to better and more readily accept the style of HMI that the standard is recommending. The standard defines the terminology and models to develop an HMI and the work processes recommended to effectively maintain the HMI throughout the lifecycle. Use of this standard should: a) provide guidance to design, build, operate and maintain HMIs to achieve a safer, more effective, and more efficient process control system under all operating conditions. b) improve the user's abilities to detect, diagnose, and properly respond to abnormal situations. The HMI is the collection of hardware and software used to monitor and interact with the control system and ultimately with the process. The target audiences are end users, designers, developers, and implementers of HMI systems.