From a macro-ergonomics perspective it is possible to explore how the factors within the overall security system contribute to the success of counter-terrorism initiatives and where gaps may exist. From the macro-ergonomics perspective a user requirements elicitation exercise was conducted at a mainline railway station in the UK to understand the work and duties of front-line personnel and management as well as the more complex system issues that surround security in this arena. It became apparent that the station relied on several security sectors working closely with one another to ensure safety and customer satisfaction. Security staff are also trained in conflict management as they are required to interact with customers who may have misunderstood the ticketing system or are travelling on invalid tickets. The chapter presents a case study of user requirements elicitation conducted for the Shades of Grey research project to illustrate the use of different human factors methods in the security domain.