In health care, guidelines and procedures are central parts of everyday clinical work (ECW). Health care staff are expected to comply and keep up to date with numerous policies and procedures covering their daily work. However, because changes inevitably occur, employees may for various reasons break, bend, modify, work around or inconsistently implement these rules. This process of compromise, mediating between work-asimagined and work-as-done, leads to innumerable small-scale ‘anomalies’ that differentiate everyday from prescribed work; these ‘anomalies’ are sometimes implicated, rightly or wrongly, in adverse events, especially when a Safety-I perspective is taken. This approach (for example, Root Cause Analysis, orthodox quality measurement and improvement) focuses on what went wrong and looks for root causes to undesirable events or unsatisfactory situations. It often leads to amending procedures (typically, adding more constraints to them) to prohibit actions that contributed to creating hazardous situations in these analyses (Reason et al., 1995). This is fundamentally a single feedback learning loop; a form of instrumental learning in which an organisation seeks to improve already existing strategies and processes through ‘patching’ (Argyris and Schön, 1996). But as a result, progress on patient safety has been slow and painful.