Simulation solution validation for an integrated emergency post

Simulation solution validation concerns the comparison between the expected and actual performance of a solution provided by a simulation model. Such a comparison might become challenging when not only the implementation of the solution changed the environment, but also the processes and data have changed. We illustrate this challenge using a case study at an Integrated Emergency Post (IEP), which is a collaboration between a general practitioners post and a hospital's emergency department to provide out-of-hours emergency care. After performing a simulation study, our solution has been implemented, after which data has been gathered for two years. We validated the solution by performing various comparisons, using simulated and realized performance, under the original and changed data and processes, and with and without the proposed solution. We propose a solution validation framework to structure these comparisons, and provide key insights regarding solution validation, using our case study at the IEP.