People familiar working on projects will understand the analogy of peeling the layers of an onion. Typically, when used in reference to projects, this refers to additional details being uncovered that weren’t initially considered. The onion analogy is apt because newly uncovered details rarely yield pleasant surprises, they usually bring tears. An HIS/EMR replacement is a significantly complex project. The magnitude of change goes beyond a single onion, it is more like a bunch, or in some cases a field. But there are ways to minimize the tears. It begins with organizational decomposition.
Many people follow the stars, or equivalent, of services such as Yelp or TripAdvisor when planning to journey into the unknown. Organizations' approaches to HIS/EMR replacement projects or any technology projects should not differ. The trick is to build it into the overall plan to avoid it becoming a list of the inevitable.