This Guide is primarily concerned with alarm systems provided for people operating industrial processes. These include alarm systems in industries such as chemical manufacture, power generation, oil and gas extraction and refining as well as other industries. The Guide has been compiled from the experience gained within such industries, however much of the guidance is generic and with appropriate interpretation can be applied in other sectors. For example, the guide has been used successfully as a basis for training in the rail and transport sectors, in the nuclear industry, and elsewhere.Guidance is included on:• The design of alarm processing systems and their functionality.• The operation of existing alarm systems and performance optimization.• The specification and purchase of new alarm systems.Alarm system functionality is now commonly included in computer-based systems used to control and monitor industrial processes, as well as being found in stand-alone dedicated computer-based alarm systems and the more basic annunciator-based or hard-wired ‘light box’ systems. This Guide is appropriate to alarm systems implemented by any of these methods, wherever a human response may be needed to an alarm condition. The guidance is designed to be practical and usable. There is overview information, and also much detailed guidance on specific issues.