In a context in which health institutions have transparency obligations toward authorities and patients, quality management and best practices—defined according to scientific standards—have become major concerns for in-house management. While protocols and regulations are necessary for orienting work, they do not apply by themselves. In providing standardized and stabilized work descriptions, these documents contribute to hiding what workers effectively do in unstable and variable situations in which numerous, sometimes contradictory, elements need to be simultaneously considered. In this study, we look into this claim made by the French ergonomics stream and we consider the serious and irreducible gap between “prescribed work” and “real work.” Such an understanding of work based on research evidence is more adapted to professional realities and provides (valued) resources in nursing education. Based on information collected in three work analysis studies conducted by our team in hospital settings, we deepen these notions and their implication for practice and education.