| Why do we want safe systems? | Safety of public, users, etc Expense; accidents are expensive. Disruption, clean up, etc Performance; want to maximise. Minimise errors and failures to increase reliability/ quality Trust; Need users to feel products are safe and reliable |
| What factor does the human role play in safety? | Alot of accidents occur due to human error May not be one big one, but lots of small ones that cause the accident |
| What is a human error definition? | Human error is an action or decision which was not intended. A violation is a deliberate deviation from a rule or procedure. |
| Draw the human failure types taxonomy and its definitions? | Stong relationship between error taxonomy and cognitive mechanisms. Slip; series of actions and do something wrong Lapse; Forget to do something, miss a step Rule-based; select wrong rule or process Knowledge based; don't have the correct knowledge, not understanding. Issues with long term memory Routine; people always doing the wrong thing Exceptional; People don't follow rules due to exceptional cicumstances |
| What are some examples of driving failure types? | Slip; Stalling at a junction, getting in the wrong gear. mirror, signal, manoover wrong Lapse; forgetting to indicate, not turning lights on, navigation wrong, not looking before crossing road. Rule based; observing signs, navigation choices Knowledge; Don't know area so in wrong lane (unfamilliar navigation) Routine; Speeding (motorway) Exceptional; Drink driving, running a red light as a civilian for emergency services (helping emergency services)!! |
| What's wrong with human error? | Doesn't account for wider socio-technical system Still very much 'at the sharp end', doesnt reflect emergent failures There is a fine line between failure and performance |
| What is the swiss cheese model? | A set of accidents have to align for an accident to occur. |
| Examples of failures that are design (task and tools) related | Cockpit controls Complexity of processes Misunderstanding of informatio Automation mode errors Information in the world (train driver goes throguh red light cus can't see it in the morning sun) |
| Examples of failures due to organisation of work (supervision) | Availability of staff Fatigue related (workers too tired, worker mis wires lights, trains collide) poor supervision Training and competence |
| Examples of failures that are organisation related | Who makes decisions? Groupthink, think in a certain way about a problem Listening to expertise Complacency and drift into failure (Prevelant in high risk activities that have been completed a number of times sucessfully) |
| What is the HFACS? | Human Factors Accident Classification System Takes error classification and swiss cheese and constructs a tree diagram of all the things that might go wrong when an accident occurs. |
| Explain 'Still very much 'at the sharp end', doesnt reflect emergent failures' | The time of the error and time of the failure are not the same. Minor problems get bigger over time Issue of confirmation bias (people who think their right tend to stick to it) |
| Explaine 'The fine line between failure and performance' | Poeple who are pushed to the limits. E.g doctors, often very close to failure |
| Explain safety differently | Idea is to look at when things are going well, not just bad. People are optimising multiple tasks Peopl find adaptations to make a system work |
| What are some features of rail signalling control? | Controlling movement authority of trains Safety and operational performance (train seperation and running on time) Give the signaller oversight to a winde range of functions (signals, when technicians can go on lines,etc) A physical task that's becoming more cognitive (levers changing to buttons and screeens) An active task that's becomming more monitoring Their in control of Risk, Recovery and Defence; Signalers are last line of defnece, maintaining safety. |
| What are examples of ways of addressing error? | Going Beyond 'Incidents'; Looking for hazards. Hearing about near misses. 'Just' and open culture where you can report near misses. Incident Investigation; Applying different types of human error (human error taxonomy). Look at other causes. Using a structured approach. Correcting the problem; Look at solutions beyond human error. Match any training to the type of 'human error'. Build resilience, if things go wrong there are processes that will manage failure, preventing it from becoming a massive event. |
