He currently serves on the Council of the Institute of Electrical Engineers and is the Chair of the Executive Committee of the Human Factors Engineering Professional Network. He has published and presented numerous papers on human factors and safety and is a licensed engineer and registered member of the Ergonomics Society.
Human factors and cost benefits
- Introduction
- Human factors or ergonomics?
- Human-centred design and systems engineering
- Human factors costs and pay-offs
- References
It is useful to review some of the history surrounding the use of the term "human factors" and place it alongside the somewhat similar term "ergonomics". Regarding the origin of the word "ergonomics", it is particularly interesting to note that for many years it was assumed that it was first coined by K.
Human factors integration
Background to HFI prior to the mid 1980s
The 1970s also saw the beginning of providing appropriate human factors standards within military equipment procurement projects. At that time, work dealing with human factors often started from the concept of the Target Audience Description (TAD).
Post mid 1980s
These led to important studies that substantiated the need to address human factors in the procurement of future naval command systems [1]. Despite all this scientific success and the development of standards and procedures, the application of human factors/ergonomics in the UK was limited.
Scope of application of HFI
The standards and supporting documentation appeared rapidly in the 1990s, both in the International Standards Organization and Defense fields (primarily in the maritime field: Sea System Publications (SSPs) 10, 11 and 11). Health and safety issues are in associated with the disadvantages and costs of not addressing them.
Life cycle management and risk
The overall approach and methodology is independent of scale or implementation - the only important aspect is the involvement of people. It is essential that they are fully understood in order to ensure the effectiveness of the HFI program.
Starting an HFI programme
- Identification of issues and risks
- Early human factors analysis
- Verification
- Validation
ISO 15288 states that: "The purpose of verification is to demonstrate that the characteristics and behavior of a product conform to the specified design requirements resulting from the Architectural Design Process". ISO 15288 states that: "The purpose of validation is to provide evidence that the services provided by the system or any element of the system when used meet the needs and requirements of their respective stakeholders".
Early human factors analyses
However, a more detailed analysis may be preferable, expressing impact in terms of effectiveness, delivery schedule or costs – the level of detail will depend on the information available, the purpose of the analysis and the way the results will be used in the future. There is still no agreed method for taking the issues from e.g. table 2.5 and determine whether one approach is better than another – a risk may be seen as worth taking if a sensible mitigation strategy is available and the premium is high enough.
The future
There is little doubt that the discipline is considered expensive even if it is a fraction of the cost of many other such specialists and the allocation of funds appears to be well underway. It also identifies the percentage of issues that are believed to be addressed.
Conclusions
So it seems that there is a lot of HFI-related work going on, especially at the beginning of the cycle and during in-service activities. However, it seems that with the current equipment there are plenty of points that need to be addressed, so early work should be in high demand to apply the lessons learned.
The report on the work on the DPA and DLO has been widely accepted and it is generally believed that the results obtained are comparable to those that would be obtained in similar industries elsewhere. Produced under TG5 (Human Factors and Effectiveness studies) of the MoD Corporate Research Program 16 TAINSH, M.
Humans: skills, capabilities and limitations
Introduction
Humans as information processors
We are exposed to a wide spectrum of information from electromagnetic energy to auditory, tactile, vestibular and kinesthetic material. By their very nature, these higher-level thought processes cannot be easily thought of in terms of information processing.
Models of information processing
The simplicity of the models means that they do not lend themselves easily to basic cognitive approaches. They do not consider what would happen to the processing when the individual was part of a group of people.
Sensations
The use of eye tracking technology is extremely useful in trying to understand the ability of the human visual system to scan a computer interface such as a web page. This is in contrast to finding required products in a web page with less information clutter, where fixations are centered on the search and navigation areas of the web page [6].
Perception
These show how 'centre' lines of the same length can appear to vary due to surrounding features. These effects may be even greater when the runway surface is sloped or where the width or texture (both perceptual cues) differ from normal expectations.
Attention
We also focus on the characteristics of the sound (pitch, intonation), and when speaking, the movements of the speaker's lips. The ability to perform two tasks simultaneously will depend on the nature of the tasks.
Memory
Likewise, unplanned instructions can be easily forgotten in emergency situations when cognitive load is highest. Understanding memory constraints can be invaluable in designing systems that reduce the likelihood of errors.
Higher order processing
Within the realm of human factors, problem solving and decision making are two critical higher order cognitive processes. Earlier it was emphasized how decision making is integrally related to problem solving and thinking in general.
Action
For example, an airplane pilot may pay attention to only the salient features of the cockpit environment rather than features that are more common. This is mainly due to the size of our body and the length of our nervous system.
When information processing goes wrong
The concern is, for example, in a military situation where the capacity is now to launch missiles at such a speed that they hit the target before humans even register that they are under attack. However, the generality that system models provide often comes at the cost of specificity, and the models therefore lack sophistication when it comes to analyzing the human component of the system.
Implications for design
While cockpit scenarios clearly demonstrate pilots' skill in executing actions based on the assessment and interpretation of different sets of information, there are certain limitations, known as resource requirements [42]. In this case, the ability to perform two tasks well will depend greatly on whether or not one task is less demanding on the crew's attention resources than the other.
Conclusions
Indeed, the demand for cognitive resources allocated to different tasks is called 'mental load' and within safety-critical environments such as an aircraft flight deck, aids and automated systems are constantly being developed to minimize the cognitive demand or mental load placed on pilots. . Reducing cognitive demands, especially in high workload situations, leads to the execution of actions that are consistent with the safe and optimal operation of a system.
N.: "Features of modeling the nervous system", in MALTZMAN, I. and COLE, K. Eds): "Handbook of contemporary Soviet Psychology" (Basic Books, New York, 1969). F.: "Warning systems for civil aircraft: future directions in information management and presentation", International Journal of Aviation Psychology p. Eds): "Principles and practice of aviation psychology" (Lawrence Erlbaum Associates, Mahwah, NJ, 2002).
The human factors toolkit
Introduction
There was little need to ensure that the design of the device was suitable for the worker. Today, in the developed world, there is a growing awareness of the benefits to be reaped from considering the human user in the design process.
The human factors approach
Methods for assessment
This chapter is intended to focus more on the cognitive measures and tools for design. However, it is intentionally not covered in detail in this chapter, as extensive and specific coverage of usability is provided in Chapter 11.
Human factors tools
- Heuristic evaluation
- Checklists
- Focus groups
- Observation
- Task analysis
- Human reliability assessment
- Experiments
- Modelling tools
- Fitting trials and mannequins
This is a new multimedia version of the SUMI (developed by the same group of people). However, the reliability and validity of the findings emerging from focus groups should be questioned.
Which method to use?
However, this resulted in high set-up and operational costs and, because workers knew they were in a research setting, some loss of ecological validity (ie, the Hawthorne effect). The extent to which the researcher influences the sequence of events and the outcome of the assessment must be taken into account.
Exercises
The extent to which reliability and validity must be taken into account depends on the application. I think I would need the support of a 1 2 3 4 5 technical person to be able to use this system.
Acknowledgements
Multiply the sum of the scores by 2.5 to get the total utility value for a particular system.
Proceedings of Human Factors and Ergonomics Society (HFES) Conference, Chicago, IL (HFES, Santa Monica, CA, 1998). Proceedings of the International Topical Meeting on Advances in Human Factors in Nuclear Power Systems (Knoxville, TN, 1986).
Task analysis
Introduction
In some situations, the issues of interest may be defined before any task analysis is undertaken. This process is illustrated in the overview model of the task analysis process presented in Figure 5.1 and the rest of this chapter is based on this structure.
Data collection for task analysis
A significant amount of task-useful information can be obtained from individual or group discussions with operational personnel or technical experts. It is also helpful if those participating in group discussions can be warned in advance of the topics to be covered.
Hierarchical Task Analysis (HTA)
This level depends on the analyst's requirements and it is often very clear when this point has been reached. At the end of the redescription process, the obtained task descriptions should provide an overall picture of the tasks involved.
Task decomposition
It is also possible to use task decomposition to record different measures of task performance. Alternatively, all decomposition data can be collected while the task descriptions are being developed.
Data analysis
Finally, the analyst must make an assessment of the impact of any alleged human error. This can be very effective, but is limited to tasks where it is possible to speak directly without any information processing.
Reporting task analysis
These are the perceptual, cognitive, or motor actions performed to achieve the goals. The keystroke-level model also defines rules for deciding when to use the mental preparation operator.
Exercises
However, if a particular recommendation is believed to be costly or difficult to implement, enough information should be available to enable a reader to gain a more complete understanding of the issue. Finally, once agreements have been made on how each recommendation will be implemented, these should be recorded and then these aspects of the system should be validated at a later date to ensure that the recommendations have been implemented in a manner that fully complies with ergonomic guidance.
Answers
For example, the first page of the second report will be printed on the back of the last page of the first report. Should the person e.g. be told the total duration of the holiday to prevent mistakes such as booking a day trip for the same day in different months.
For example, if toast is desired at the end of the meal, the time when toasting can begin depends on whether the guests want warm or chilled toast. S.: 'Task analysis to support the design of a safety system for nuclear power plants', Ergonomics pp.
Automation and human work
Introduction
Here, the accuracy of the clock was critically dependent on having a constant trickle or flow of water, which in turn was dependent on the pressure or water level in the reservoir. This was actually one of the reasons for the emergence of human factors engineering as a scientific discipline in the late 1940s.
Humans and automation
Many human traits are heuristic rather than algorithmic in nature, meaning they are difficult to formalize and implement in a machine. In the context of process control, the human-machine system is seen as a shared cognitive system capable of maintaining process control under various conditions.
Cognitive systems engineering
Even with this simple type of automation, there are problems related to detection sensitivity, i.e. the criterion of whether a movement has occurred. Bainbridge argued that "the increased interest in human factors among engineers reflects the irony that the more advanced the control system, the more crucial the contribution of the human operator can be" ([6], p. 775).
Exercises
As long as automation cannot be made fully autonomous, but requires some form of human-machine collaboration to take place, the design must address the common system as a whole rather than focusing on specific and particular functions. Find examples of how technological improvements have resulted in increased performance rather than increased security.
It describes the background for humans and automation with examples from many domains; the design of human automation systems; and the generic research issues. This chapter discusses the roles of humans and machines and the importance of information management as a crucial element in the design of human automation systems.
To engineer is to err
- Humans degrade basically safe systems. Or do they?
- Human error or mechanical failure?
- Why don’t they just follow the procedures?
- Automation as a solution to the human error problem?
- Unknowable futures and irreconcilable constraints
- References
It is quite impossible for any design to be the "logical result of the requirements" simply because, since the requirements are in conflict, their logical result is impossible. 4 VAUGHAN, D.: 'The Challenger Launch Decision: Dangerous Technology, Culture and Deviance at NASA' (University of Chicago Press, Chicago, IL, 1996).
Qualitative and quantitative evaluation of human error in risk assessment
Introduction
Human reliability analysis in risk assessment
It will be appreciated that some failure probabilities in the event tree can easily be the result of human error. In particular, it is possible to account for changes in the probabilities of the event tree due to preceding events.
A systematic human interaction reliability assessment methodology (HIRAM)
This phase includes the prediction of errors that may occur, using human error models and the analysis of the factors affecting performance, and the nature of the human interactions involved (e.g. actions, control, communication). Each of the stages of HIRAM is discussed in detail in the following sections.
Criticality analysis
- Likelihood of task failure
- Severity of consequences
It can be reasonably argued that the probability of subtask failure is unlikely to be known at this stage. Only those tasks above a predefined TCI level (as a function of time and resources) will be subjected to a detailed analysis.
Qualitative human error analysis
- Action errors
- Checking errors
- Retrieval errors
- Communication or transmission errors
- Selection errors
- Planning errors
- Perform task analysis
- Perform Predictive Human Error Analysis (PHEA)
- Perform consequence analysis
- Perform recovery analysis
- Error reduction analysis
It is concerned with retrieving information from memory (eg the time required for a reactor to fill), or from a visual display or a procedure. The mistake in this context would be to select the online filter for priming instead of the offline one.
Representation of the failure model
The overall operator failure probability is obtained by multiplying the AND gate probabilities and combining the OR gate values as shown in Table 8.4. As described in Section 8.2, the total failure probability is given by summing the probabilities of all the resulting failure states.
Quantification
- Modelling the task
Since the ESD was not functioning properly, the control room operator or supervisor must identify the malfunctioning ESD valves and then send an outside operator to the appropriate equipment room to manually close the valves. The probability of each error state on the far right side of the diagram is calculated as the product of the error probability and/or success probability at each branch node leading to the state.
