Checklist

A checklist is a type of job aid used in repetitive tasks to reduce failure by compensating for potential limits of human memory and attention. Checklists are used both to ensure that safety-critical system preparations are carried out completely and in the correct order, and in less critical applications to ensure that no step is left out of a procedure. They help to ensure consistency and completeness in carrying out a task. A basic example is the "to do list". A more advanced checklist would be a schedule, which lays out tasks to be done according to time of day or other factors, or a pre-flight checklist for an airliner, which should ensure a safe take-off.
A primary function of a checklist is documentation of the task and auditing against the documentation. Use of a well designed checklist can reduce any tendency to avoid, omit or neglect important steps in any task. For efficiency and acceptance, the checklist should easily readable, include only necessary checks, and be as short as reasonably practicable.

History

It is widely accepted that checklists appeared after the crash of the Boeing B-17 plane on October 30, 1935. Possibly, the source of such common knowledge is The Checklist Manifesto book by Atul Gawande. However, the Oxford English Dictionary states that the word appeared in 1853.
The earliest discovered evidence of the “check-list” usage is seen in the “Journal of the House of Representatives of the State of New Hampshire at Their Session Holden at the Capitol in Concord” issued in 1841 and describing the elections-related events of the autumn of 1840.

Purpose

In general, a checklist is a quality management tool, an aid to completing a complex task correctly and completely. It is an aid to recall, provides a reminder of the correct sequence, and uses the operator's knowledge and skill efficiently to ensure that no critical steps are omitted, even when the operator is under stress or has degraded attention due to fatigue or other distractions, It allows cross checking, keeps team members informed of the status of readiness, and can provide a legal record of a sequence of events to indicate due diligence. It differs from an instruction manual or operating manual in that it does not normally provide details on how to perform the steps, as it assumes that the operator is competent and familiar with each step.

Applications

Safety critical systems

Checklists are used to help avoid accidental omission of important preparation of equipment and systems. These may be routine operations like pre-flight checks on an airliner or relatively infrequent occasions like commissioning a nuclear power station or launching a spacecraft. The value of checklists is proportional to the complexity of the system and the consequences of a system failure. They may also aid in mitigating claims of negligence in public liability claims by providing evidence of a risk management system being in place. A signed off checklist with a document describing the listed checks may be accepted as evidence of due diligence. Conversely, the absence of a mandatory checklist may be considered evidence of negligence.

Aviation and space flight safety

Checklists have long been a feature of aviation safety to ensure that critical items are not overlooked. The best known example is the cockpit preflight checklist, which is intended to ensure that the crew correctly configures the aircraft for flight on every flight. A normal checklist is used before critical flight segments, such as takeoff, approach and landing, which are the phases in which the highest incidence of accidents occur due to procedural error. Checklists are also used for troubleshooting, to identify and where practicable, correct malfunctions. They cannot substitute for pilot skill and learned and practiced immediate response to critical malfunctions, but are useful for mitigation attempts when time allows.

Health care

In health care, particularly surgery, checklists may be used to ensure that the correct procedure is carried out on each patient. Checklists have been used in healthcare practice to ensure that clinical practice guidelines are followed. An example is the WHO Surgical Safety Checklist developed for the World Health Organization and found to have a large effect on improving patient safety. According to a meta-analysis after introduction of the checklist mortality dropped by 23% and all complications by 40%, but higher-quality studies are required to make the meta-analysis more robust. Checklist use in healthcare has not always met with success and transferability between settings has been questioned. A survey found them to have no statistical effect in a cohort of hospitals in the Province of Ontario in Canada. In the UK, a study on the implementation of a checklist for provision of medical care to elderly patients admitting to hospital found that the checklist highlighted limitations with frailty assessment in acute care and motivated teams to review routine practices, but that work is needed to understand whether and how checklists can be embedded in complex multidisciplinary care.

Underwater diving

In professional diving, checklists are used in the preparation of equipment for a dive, and to ensure that the diver and life support systems are fully prepared before they enter the water. To a lesser extent, checklists are used by a minority of recreational divers, and by a larger proportion of technical divers during pre-dive checks. Studies have shown checklists to be effective at reducing the number of errors and consequent incidents.

Quality assurance applications

Used in quality assurance of software engineering, to check process compliance, code standardization and error prevention, and others.
Often used in industry in operations procedures
In civil litigation to deal with the complexity of discovery and motions practice. An example is the open-source litigation checklist.
Used by some investors as a critical part of their investment process,
The creation of emergency survival kits, first aid kits and other collections of diverse apparatus, to ensure that the set is complete.
Janitorial checklists are used for quality control.
For information
An ornithological checklist, a list of birds with standardized names that helps ornithologists communicate with the public without the use of Latinised scientific names.
A biodiversity checklist is a list of organisms recorded from a given geographical region or taxon. These include worldwide lists indicating the continued existence of species within specified taxa, and are also used to record the species found in countries, bioregions, or specific protected areas. They may be a form of database.
A popular tool for tracking sports card collections. Randomly inserted in packs, checklist cards provide information on the contents of sports card set.
Effectiveness of checklists

Ranapurwala et al. found:
Characteristics of effective checklists include:

Checklists should be simple and convenient to use. Each listed item should be necessary and together they should be sufficient.
Checklists focused on the responsibilities of a specific person, or a group who will work together, are less likely to have items left out.
Grouping items which can be done at the same time or place, or by the same person, often improves efficiency.
* A group may have a checkbox to indicate completion of the group. This is more likely to be helpful if there are several groups.
Where reasonably practicable the items to be checked by a specific person can be grouped on the list. This makes it easier for them to keep track of what they have done and must still do. In some cases it may help to split them off as a separate checklist.
Items should not be over-detailed in description nor ambiguous. A checklist should not try to define or describe procedures which should be familiar to the checker, though critical steps may usefully be listed in order when order is important.
Ordering of the list should be logical. Where chronological order is important, it should be indicated by order on the list. Where items to be checked are spatially distributed, an order minimising travel or search time is efficient.
The most convenient and reliable checklists are normally completed from top to bottom in a single session. It should be easy to recover from any interruption without risking missing an item or redoing a check unnecessarily.
The physical checklist must be convenient to use on site. It should not require special effort to read, or protect it from the environment.
It may be useful to cross-reference the checklist to the standard procedure, where the process is definitively described in detail, particularly for training and audit purposes. This makes it easy to check if there is any doubt.
Some checklists must be signed off and kept as evidence, others may be re-usable. This may affect the format and materials.
Checkboxes at the beginning of each item are easier to find and follow to the next incomplete check. A keyword at the beginning of the text will help ensure that the correct box is ticked.
When several checklists are used, due to complexity of the task, or the need for several people to make checks at different places, a master checklist indicating the completion of each subordinate checklist may be used.
If instructions are necessary, they should be included. If not, they should be left out as they will distract the user.
Types
Lists of actions for standard procedures, in which details are provided for each step.
Lists of actions for standard procedures, in which no or very little detail is provided for each step on the assumption that the operator is entirely familiar with each step, and the checklist is used to ensure that no steps are omitted, or the preferred order is followed
Project coordination lists, which specify who is responsible for each part of the project.
Troubleshooting checklists, which may have multiple branches for diagnosis, or a series of procedures for responding to an emergency
Checklists to increase objectivity in decision-making, to reduce emotional influences.
Lists of things to be done over a specified period.