The large-scale relocation of a paediatric hospital is a significant undertaking. New environments change the system, and ways of working must adapt to maintain quality healthcare. There are risks to patients and staff well-being, with high anxiety around change. There is evidence for the efficacy of simulation as a tool for safe training and rehearsal of staff and teams 
but less so on such a large scale. Simulation for many is still perceived as a test of performance and a threat. We connected with the international simulation community to design a hospital-wide programme of Patient Environment Simulations for Systems Integration (PESSI). This paper outlines challenges in establishing buy-in from stakeholders and departments, developing a framework for implementation and our reflections on delivery of large-scale simulation activities to assist a hospital move.
How can simulation-based methodology be used to support clinical departments on a large scale to adapt/integrate/prepare in moving to a brand-new hospital?
Collaboration with authors of PEARLS for system integration use 
, using it as the main framework for delivery and structure of PESSI. Stages of delivery were: pre-phase work, system testing day, debrief/reflection and evaluation. Immediate feedback of enjoyment and learning was collated from all participants. Three-month post-move feedback is planned to review ongoing impact/behaviour change plus analysis of safety incidents.
Pre-phase work involved meeting stakeholders and establishing aims of testing. Ward managers were key departmental links, meeting with members of PESSI to plan scenarios. System testing days involved familiarizing themselves with the environment, followed by ‘day in the life’ simulations with a representation of the whole team. All participants were called ‘co-faculty’ and knew exactly what would happen. Debrief involved facilitated conversations with the whole team describing reactions, and deeper analysis of the key events, with concerted efforts by facilitators to give a balanced approach of positives and challenges. A short report was given back to the department detailing the findings teams would need solutions to. Solutions from simulation were implemented prior to the move, increasing staff confidence, with many feeling PESSI played a major role in feeling prepared for the new site. The PESSI framework is being utilized in adult services and we hope to publish our methodology to share with the wider simulation community.