This document provides general requirements and recommendations based on ergonomic principles to improve the quality of service in situations between service providers and users (i.e., customers and citizens). This document is intended for the following types of target groups: 1. Groups that provide services directly - Service providers who provide services directly to users 2. Groups that plan and manage the services - Managers who are involved in planning, managing, and developing products, system and/or service projects - Those who procure products, systems, and services - Those who plan and create services 3. Groups that evaluate services - Those who evaluate services by conducting research on and identifying user needs and behaviours