Workload: Difference between revisions

{{refimprovemore citations needed|date=February 2013}}

The term '''workload''' can refer to a number ofseveral different yet related entities. However, it is clear that cognitive

WorkloadAn isold definition refers to workload as the amount of work an individual has to do.<ref name="Jex 1998">Jex, S. M. (1998). Stress and job performance: Theory, research, and implications for managerial practice. Thousand Oaks, CA: Sage.</ref> There is a distinction between the actual amount of work and the individual's perception of the workload.<ref name = "Jex 1998"/> Workload can also be classified as quantitative (the amount of work to be done) or qualitative (the difficulty of the work).<ref name = "Jex 1998"/>

Workload can also refer to the total energy output of a system, particularly of a person or animal performing a strenuous task over time. One particular application of this is [[powerlifting|weight lifting]]/[[weights training]], where both anecotalanecdotal evidence and scientific research hashave shown that it is the total "workload" that is important to muscle growth, as opposed to just the load, just the volume, or "time under tension". In these and related uses of the word, "workload" can be broken up into "work+load", referring to the work done with a given load. In terms of weights training, the "load" refers to the heaviness of the weight being lifted (20&nbsp;kg is a greatermore significant load than 10&nbsp;kg), and "work" refers to the volume, or the total number of [[wots this?|rep]]s and sets done with that weight (20 reps isare more work than 10ten reps, but 2two sets of 10 reps isare the same work as 1 set of 20 reps, its just that the human body cannot do 20reps of a heavy weight without a rest, so its best to think of 2x10 as being 20 reps, with a rest in the middle).

This theory was also used to determine [[horse power]] (hp), which was defined as the amount of work a horse could do with a given load over time. The wheel that the horse turned in Watt's original experiment put a certainspecific load on the horse's muscles, and the horse could do a certain amount of work with this load in a minute. Provided the horse was a perfect machine, it would be capable of a constant maximum workload, so. increasingIncreasing the load by a given percentage would result indecrease the possible work done decreasing by the same percentage, so that it would still equal "1 hp". Horses are, obviously, not perfect machines and, over short time periods, are capable of as much as 14&nbsp;hp, and over long periods of exertion, output an average of less than 1&nbsp;hp.

The theory can also be applied to [[automobiles]] or other machines, which are slightly more "perfect" than animals. Making a car heavier, for instance, increases the load that the engine must pull. Likewise, making it more aerodynamic decreases drag, which also acts as a load on the car as well. Torque can be thought of asconsidered the ability to move a load, and the revs are how much work it can do with that load in a given amount of time. Therefore, torque and revs together create kilowatts, or total power output. Total output can be related to the "workload" of the engine/car, or how much work it can do with a given amount of load. As engines are more mechanically perfect than animals' muscles, and do not fatigue in the same waysimilarly, they will conform much more closely to the formula that if you apply more load, they will do less work, and vice versa.

{{Main article|Occupational stress}}

In an occupational setting, dealing with workload can be stressful and serve as a [[stressor]] for employees. There are threeThree aspects of workload that can be stressful.

Workload has been linked to a number of strains, including [[anxiety]], physiological reactions such as [[cortisol]], fatigue,<ref>{{cite journal | author = Ganster, D. C., & Rosen, C. C. (| year = 2013). | title = Work stress and employee health: A multidisciplinary review. | journal = Journal of Management, | volume = 39( | issue = 5),| 1085-1122.pages = 1085–1122 | doi: = 10.1177/0149206313475815 | s2cid = 145477630 }}</ref> backache, headache, and gastrointestinal problems.<ref>{{cite journal | author = Nixon, A. E., Mazzola, J. J., Bauer, J., Krueger, J. R., & Spector, P. E. (| year = 2011). | title = Can work make you sick? A meta-analysis of the relationships between job stressors and physical symptoms. | journal = Work & Stress, | volume = 25(1), | issue = 1-22.| doi:pages = 1–22 | http://dx.doi.org/ = 10.1080/02678373.2011.569175 | s2cid = 144068069 }}</ref>

Workload as a work demand is a major component of the demand-control model of stress.<ref>{{cite journal | author = Karasek, R. A. (| year = 1979). | title = Job demands, job decision latitude, and mental strain-implications for job redesign. | journal = Administrative Science Quarterly, | volume = 24( | issue = 2),| 285-308pages = 285–308 | doi=10.2307/2392498| jstor = 2392498 }}</ref> This model suggests that jobs with high demands can be stressful, especially when the individual has low control over the job. In other words, control serves as a buffer or protective factor when demands or workload is high. This model was expanded into the demand-control-support model, thatwhich suggests that the combination of high control and high social support at work buffers the effects of high demands.<ref>{{cite journal | author = Johnson, J. V., & Hall, E. M. (| year = 1988). | title = Job strain, work place social support, and cardiovascular disease: A cross-sectional study of a random sample of the Swedish working population. | journal = American Journal of Public Health, | volume = 78( | issue = 10),| pages = 1336–1342 | doi=10.2105/ajph.78.10.1336| pmid = 3421392 | pmc = 1349434}}</ref> A 2019 survey by Cartridge People identified workload as the main cause of occupational stress.<ref>{{Cite web |title=What's Causing UK Workers Stress in 2019 |url=https://www.cartridgepeople.com/info/blog/uk-1342workers-stress-statistics |access-date=2023-10-28 |website=www.cartridgepeople.com |language=en}}</ref>

As a work demand, workload is also relevant to the [[job demands-resources model]] of stress that suggests that jobs are stressful when demands (e.g., workload) exceed the individual's resources to deal with them.<ref>{{cite journal | author = Demerouti, E., Bakker, A. B., Nachreiner, F., & Schaufeli, W. B. (| year = 2001). | title = The job demands-resources model of burnout. | journal = Journal of Applied Psychology, | volume = 86( | issue = 3),| 499-512.pages = 499–512 | doi: http://dx.doi.org/= 10.1037/0021-9010.86.3.499 | pmid = 11419809 }}</ref><ref>Bakker, A. B., & Demerouti, E. (2014). Job demands-resources theory. In P. Y. Chen & C. L. Cooper (Eds.). Work and wellbeing Vol. III (pp. 37-64), Chichester, UK: Wiley-Blackwell</ref>

[[File:KTS1workload.jpg|thumb|Figure 1: Wickens’Wickens' Multiple Resource Theory (MRT) Model]]

Wickens’Wickens' (1984) multiple resource theory (MRT) model <ref>Wickens, C.D. (1984). "Processing resources in attention", in R. Parasuraman & D.R. Davies (Eds.), ''Varieties of attention'', (pp. 63–102). New York: Academic Press.</ref> is illustrated in figure 1:

Wickens’Wickens' MRT proposes that the human operator does not have one single information processing source that can be tapped, but several different pools of resources that can be tapped simultaneously. Each box in figure 1 indicates one cognitive resource. Depending on the nature of the task, these resources may have to process information sequentially if the different tasks require the same pool of resources, or can be processed in parallel if the task requires different resources.

Wickens’Wickens' theory views performance decrement as a shortage of these different resources and describes humans as having limited capability for processing information. Cognitive resources are limited, and a supply and demand problem occurs when the individual performs two or more tasks that require a single resource (as indicated by one box on the diagram). Excess workload caused by a task using the same resource can cause problems and result in, errors, or slower task performance. For example, if the task is to dial the phone, then no excess demands are being placed on any one component. However, if another task is being performed at the same timesimultaneously that makes demands on the same component(s), the result may be an excess workload.

The relationship between workload and performance is complex. It is not always the case that as workload increases, performance decreases. Performance can be affected by workload being too high or too low (Nachreiner, 1995). SustainedA sustained low workload (underload) can lead to boredom, loss of situation awareness and reduced alertness. Also, as workload increases, performance may not decrease as the operator may have a strategy for handling task demands.

Wickens’Wickens' theory allows system designers to predict when:

Like Wickens, McCracken and Aldrich (1984), like Wickens, describe the processing, not as one central resource but as several processing resources: visual, cognitive, auditory, and psychomotor (VCAP). All tasks can be decomposed into these components.

They developed rating scales for each of the VCAP componentscomponent, which provide a relative rating of the degree to which each resource component is used.

Joseph Hopkins (unpublished) developed a training methodology,. where theThe background to his training theory is that complex skills are, in essence, resource conflicts where training has removed or reduced the conflicting workload demands, either by higher -level processing or by predictive time sequencing. His work is in effect based on Gallwey (1974) and Morehouse (1977). The theory postulates that the training allows the different task functions to be integrated into one new skill. An example of this is learning to drive a car. Changing gear and steering are two conflicting tasks (i.e. both require the same resources) before they are integrated into the new skill of "driving". An experienced driver will not need to think about what to do when turning a corner (higher level processing) or alternatively may change gear earlier than required to give sufficient resources for steering roundaround the corner (predictive time sequencing).

With any attempt at creating a workload model, the process begins with understanding the tasks to be modelled. This is done by creating a task analysis that defines:

These numerical values against each resource type of resource are then entered into the workload model. The model sums the workload ratings within each resource and across concurrent tasks. The critical points within the task are therefore identified. When proposals are made for introducing new devices onto the current baseline activities, thethis impact of this can then be compared to the baseline.

Possibly oneOne of the most advanced workload models was possibly developed by K Tara Smith (2007):. thisThis model integrated the theories of Wickens, McCracken and Aldrich and Hopkins to produce a model that not only predicts the workload for an individual task but also indicates how that workload may change given the experience and training level of the individuals carrying out that task.

* Does the operator have the capability to perform the required tasks?

* Does the operator have enough spare capacity to cope with emergency situationsemergencies?

* Can the task or equipment be altered to increase the amount of spare capacity?

===Cognitive workload in time -critical decision-making processes===

It is well accepted that there is a relationship between the media by which information is transferred and presented to a [[decision maker]] and their cognitive workload. During times of concentrated activity, single-mode information exchange is a limiting factor. Therefore, the balance between the different information channels (most commonly considered to be visual processing and auditory, but could also include haptic, etc.) has a direct effectdirectly onaffects cognitive workload (Wickens 1984). In a [[time-critical]] decision situation, this workload can lead to [[human error]] or delayed decisions to accommodate the processing of the relevant information. (Smith, K.T. & Mistry, B. 2009).<ref>Smith, K.T., Mistry, B (2009) Predictive Operational Performance (PrOPer) Model. Contemporary Ergonomics 2009 Proceedings of the International Conference on Contemporary Ergonomics 2009 http://www.crcnetbase.com/doi/abs/10.1201/9780203872512.ch28</ref>

* '''workload debt''' - which is when an individual’sindividual's cognitive workload is too high to complete all relevant tasks in the time available, and they decide (either consciously or subconsciously) to postpone one or more tasks (usually low priority tasks) to enable them to makedecide the decision inon the required timeframe.

* '''workload debt cascade''' - which is when, because of the high workload, the postponed tasks mount up so that the individual cannot catch up with the tasks that they are required to do, causing failure in subsequent activities.