Working curve
The work curve ("Kraepelin's work curve ") is a curve in work physiology that describes the course of the work performance of a worker during working hours .
General
Human work performance does not remain constant over time, but is subject to more or less large fluctuations. These can affect the volume of work and the work result ( product quality / service quality ). The workers and managers must therefore be aware of the existence of such fluctuations in performance within the framework of quality management and time management so that they can make greater use of performance peaks and compensate for performance lows as bridging as possible. The findings on which the work curve is based generally apply to work in people's private lives and can then be referred to as the performance curve.
The work curve and work performance are objects of knowledge, especially in work physiology , work psychology , occupational medicine , sports medicine and business administration .
history
The psychiatrist Emil Kraepelin began in 1890 with experiments - as he called it - "hygiene at work" and researched the psychological connections between fatigue and exercise at work . He hoped to find out about the relationship between working hours and work performance and the occurrence of signs of fatigue in order to be able to derive occupational hygiene measures from this. His analyzes of the workflow using the tools of modern scientific psychology were new and promising at the time. In a commemorative publication for the 70th birthday of his teacher Wilhelm Wundt , Kraepelin published an M-shaped curve in his essay "The Work Curve" in 1902, which reproduced the fluctuations in workforce performance within 24 hours. The m-shaped curve gave the working curve the name "physiological m-curve". Kraepelin's colleague Otto Graf (1893–1973) recognized that, in addition to other influences, the circadian rhythm (fluctuations in performance over the course of the day) also influences the physiological work curve. In 1934 he presented a general “physiological work curve” that was supposed to map the “daily fluctuations in performance”. In 1954, Graf mirrored the working curve and referred to the mirroring as the "error curve" because the performance lows tended to lead to an accumulation of errors .
Influencing variables
The mental and physical work performance is physiologically a process of consumption that initially depletes the energy reserves of the organs involved , but at the same time also affects the entire organism ; the working curve decreases with the energy consumption. Essential influencing variables of work performance are the biorhythm , exercise , occurring human fatigue and recovery phases , distraction and the workload at the workplace . From a physiological point of view, exercise is all relief and thus possible acceleration of a work process that occurs through the repetition of an activity . Fatigue is an essential part of every activity and has an inhibiting effect on work performance. If it does not exceed a certain level, you can work almost without feeling tired ( English steady state ). Recovery - after work breaks - is reversible and changes that reduce performance disappear.
The performance of the worker in the work process is not only dependent on the physiological willingness to perform and its fluctuations, but also essentially on the will to perform and work motivation ( positive criteria ) and reluctance to work , conflict situations , poor working conditions (e.g. high or low temperatures , low -oxygen air ) in the negative Senses . At the start of work, the positive aspects increase and the negative ones decrease; at the end of working hours, an increase in the physiological work curve in the sense of the final drive can be observed, especially on Friday because of the approaching weekend .
The performance disposition - it corresponds to the typical course of the work curve - is cheapest in the morning and in the afternoon and unfavorable at night . The changed sleep behavior due to night work does not change anything. An above-average external energy supply and work breaks are required in order to enable night work despite the low performance with adequate work performance. The phases of the most unfavorable performance dispositions are also compensated for by increased commitment to performance. Changing shift work or even only night work cannot change the biological course of the work curve; there is only an adjustment in the sense of a pseudo-familiarization, but no real familiarization and also no adjustment .
Curve progression
The work curve is a coordinate system with the work time as the abscissa and the work output as the ordinate . The fluctuating willingness to perform depends on the different vegetative functions of the organism at different times of the day . So for example, allows the heart - and circulatory function - as measured by pulse rate and blood pressure - in the morning and afternoon hours, a performance high while the circulatory function at night, between 02:00 and 04:00 with their low point, as against 03:00 is in gentle cycle ("physiological circulatory collapse").
Between 9:00 a.m. and 11:00 a.m., most employees have a high performance (increasing ability to think , creativity and concentration ), from 10:00 a.m. they also have high performance ( short-term memory ), the performance peak is around 11:00 a.m. The performance low begins with the digestible lunch between 1:00 p.m. and 3:00 p.m., around 4:00 p.m. a small, failing high performance begins, between 5:00 p.m. and 7:00 p.m. the long-term memory works well, but fatigue already occurs a. The workload has since declined rapidly, bottoming out after midnight. There is therefore a time window of around 2 hours (25% of the total working time) for the daily maximum performance on an eight-hour day .
This daily curve can also be carried over to the entire week, here the performance high is on Tuesday morning, the performance low on Thursday afternoon increases again slightly for Friday due to the final drive. It is no coincidence that many jour fixe fall on a Tuesday morning. The learning curve corresponds exactly to this work curve .
Consequences
Knowing these fluctuations in performance enables workers to react to them in order to make the most of these fluctuations. In this way, a high performance can be used for particularly complicated tasks or tasks that require a high level of concentration ( analyzes , complicated sequences ), while performance lows can be bridged with less difficult activities ( filing ) or work breaks. Work breaks, in turn, set a subsequent recovery process in motion. The combination of the daily and weekly curves shows that meetings ( board meetings ) should be held as effective as possible on Tuesday mornings , while tactical appointments are set on Thursday afternoons when the invitee wants to get the invited to agree quickly because they are tired.
criticism
The general application of this performance curve is problematic in everyday life . Individual differences between early risers and night owls are just as neglected as the current health disposition . In addition, it is often overlooked in popular scientific literature that the performance curves represent averages and generalizations of data and therefore the mean value cannot be applied to everyone. For example, sports physiologist Hans-Volkhart Ulmer from Mainz criticizes the method on which the performance curve is based and criticizes "the longevity of doctrines when they are proclaimed by authorities" and "the careless handling of statistics and biological scatter". In this context he speaks of "data deadlock".
Web links
Individual evidence
- ↑ Gangolf Hübinger / Rüdiger vom Bruch / Friedrich Wilhelm Graf: Culture and Sciences around 1900: II Idealism and Positivism. 1997, p. 192
- ↑ Hans W. Gruhle: Kraepelins Importance for Psychology , in: Archives for Psychiatry and Nerve Diseases 87 , 1929. P. 43
- ↑ John P. Hylan, Emil Kraepelin: About the effect of short working hours , in: Emil Kraepelin (Ed.): Psychologische Arbeit, Volume 4, Issue 3, 1902, pp. 454–494
- ↑ Otto Graf, Investigations on the Effect of Inevitable Timing of Work Processes (III) , Work Physiology 7, 1934, pp. 358-380
- ^ Otto Graf: Occupational Physiology. 1960, p. 15
- ↑ Oswald Passkönig, Wilhelm Max Wundt: The Psychology of Wilhelm Wundt: a summary of the individual, animal and ethnic psychology , part 1, 1912, p. 90
- ↑ Otto Graf: Arbeitssphysiologie , 1960, p. 56
- ^ Otto Graf: Arbeitssphysiologie , 1960, p. 57
- ↑ Hedwig Mitis: The book of the young housewife , Volume 1, 1972, p. 105
- ↑ Welf Hamer: Transferable skills. 2012, p. 12
- ↑ Hans-Volkhart Ulmer: Graf's concept of "daily fluctuations in performance" - a paradigmatic error as a result of incorrect generalization , n.d. In: uni-mainz.de (PDF; 117 kB)