Safety, reliability, and productivity in the nuclear industry result from a systematic consideration of human performance. A plant or other facility consists of both the engineered system and the human users of that system. It is therefore crucial that engineering activities consider the humans who will be interacting with those systems. Engineering design, specifically instrumentation and control (I&C) design, can influence human performance by driving how plant personnel carry out work and respond to events within a nuclear power plant. As a result, human–system interfaces (HSIs) for plant operators as well as the maintenance and testing of the I&C system cannot be designed by isolated disciplines. The focus of this publication is to integrate knowledge from the disciplines of human factors engineering (HFE) and I&C to emphasize an interdisciplinary approach for the design of better HSIs and consequently improved human performance in nuclear power plants. This is accomplished by practical explanations of the HFE processes and corresponding outputs that inform the I&C development. More specifically, the publication addresses issues in the design process where collaboration between HFE, I&C and other important disciplines and stakeholders is paramount and identifies key tools and tasks for exchanging inputs and outputs between different design disciplines, particularly I&C and HFE. The practical information provided in this publication is intended to support Member States’ capabilities to improve their approach to I&C through the consideration of HFE.