Level of ECM classification			Category	Definition
Main level (n = 5)	SRK level (n = 15)	Sublevel (n = 20)
Technical	T-EX	T-EX	External	Technical failures beyond the control and responsibility of the investigating organisation
	TD	TD	Design	Failures due to poor design of equipment, software, labels or forms
	TC	TC	Construction	Correct design, which was not constructed properly or was set up in inaccessible areas
	TM	TM	Materials	Material defects not classified under TD or TC
Organisational	O-EX	O-EX	External	Failures at an organisational level beyond the control and responsibility of the investigating organisation, such as in another department or area (address by collaborative systems)
	OK	OK	Transfer of knowledge	Failures resulting from inadequate measures taken to ensure that situational or domain-specific knowledge or information is transferred to all new or inexperienced staff
	OP	OP	Protocols	Failures relating to the quality and availability of the protocols within the department (too complicated, inaccurate, unrealistic, absent or poorly presented)
	OM	OM	Management priorities	Internal management decisions in which safety is relegated to an inferior position when faced with conflicting demands or objectives. This is a conflict between production needs and safety. An example of this category is decisions that are made about staffing levels
	OC	OC	Culture	Failures resulting from collective approach and its attendant modes of behaviour to risks in the investigating organisation
Human	H-EX	H-EX	External	Human failures originating beyond the control and responsibility of the investigating organisation. This could apply to individuals in another department
	HK: knowledge-based behaviour	HKK	Knowledge-based behaviour	The inability of an individual to apply their existing knowledge to a novel situation. Example: a trained blood bank technologist who is unable to solve a complex antibody identification problem
	HR: rule-based behaviour	HRQ	Qualifications	The incorrect fit between an individuals training or education and a particular task. Example: expecting a technician to solve the same type of difficult problems as a technologist
		HRC	Coordination	A lack of task coordination within a health care team in an organisation. Example: an essential task not being performed because everyone thought that someone else had completed the task
		HRV	Verification	The correct and complete assessment of a situation including related conditions of the patient and materials to be used before starting the intervention. Example: failure to correctly identify a patient by checking the wristband
		HRI	Intervention	Failures that result from faulty task planning and execution. Example: washing red cells by the same protocol as platelets
		HRM	Monitoring	Monitoring a process or patient status. Example: a trained technologist operating an automated instrument and not realising that a pipette that dispenses reagents is clogged
	HS: skill-based behaviour	HSS	Slips	Failures in performance of highly developed skills. Example: a technologist adding drops of reagents to a row of test tubes and then missing the tube or a computer entry error
		HST	Tripping	Failures in whole body movements. These errors are often referred to as “slipping, tripping, or falling”. Examples: a blood bag slipping out of one’s hands and breaking or tripping over a loose tile on the floor
Patient-related	PRF	PRF	Patient-related factor	Failures related to patient characteristics or conditions, which are beyond the control of staff and influence treatment
Unclassifiable	X	X	Unclassifiable	Failures that cannot be classified in any other category