Shift work is needed for primarily for two reason. First is to utilize expensive physical facilities to the maximum, and second is to ensure that some essential activities, that extend beyond normal one shift working are carried out without interruption. Thus when companies invest billions of dollars in a factory they like to operate such facilities round the clock,that is twenty-four hours a day, to get maximum returns from such investments. Then there are some activities that need to be carried out round the clock. Think of a facility that monitors the movements of missiles approaching a country to ensure protection of the country and its people from any surprise attack. This facility cannot be shutdown.
For all such work, the total working time is divided in suitable time periods for which people can work continuously for the day with reasonable degree of effort and inconvenience. In practice any work which extends beyond daytime working hours, for example between 7:00 am and 6:00 pm, is defined as shift work. While shift work improves utility of equipments and provides the society some essential services round the clock, it creates some problems for the workmen.
Shift working interferes with body's natural rhythm called 'diurnal' or 'circadian' rhythms. Thus a person working at night shift is made to work when body is in best condition. to rest, and rest when the body in best condition to work. This can result in several disorders. For example studies have found out that a person working in night shift sleeps 1.5 hours less than a person working during normal day working hours. It causes problems such as stomach, digestive, and cardiovascular diseases.
Shift working also results in reduced work efficiency and increases accident rates.
Another major problem of shift working for the individual is the disruption in normal social life. Night work makes it impossible for the individual to participated the many social events that usually take place in the evenings. Many people working at night, have also found it difficult to interact with their children because when they are at home and awake, they may be away at work or sleeping.
There are many activities that require intense physical effort that is required to work shifts.By proper organization of labor based on ergonomic principles, through the mechanization and computerization of activities and by determining how many staff structure it can act effectively to reduce physical exertion.
In the public relations services or Secretariats exist elements that an important contribution to increasing mental effort. In this sense dialogue is particularly noted to be maintained by each person to determine the desired information. In order to meet that demand, usability studies indicate a number of qualities that must have workers from such a service, namely: good knowledge in the field of applied art of talking to people, dynamism, attention to distributive , sense of observation capacity of decision and initiative.Practice has shown that in the public relations services there are a number of cases which usually leads to overload. They are diverse and can be caused either by workers or customers. The first type is the degree of fatigue of workers (plus the accumulated daily) with implications on how to behave towards clients, lack of courtesy,manifested by nervousness.
People who do not have a fixed schedule and working in shifts are more susceptible to diabetes, become obese or have heart problems because of metabolic disturbance.
According to a study made by Harvard University of USA it has observed that shift program makes us sick. In this study 10 students were volunteers, five girls and five boys, who for two weeks worked eight hours shifts each , including night shifts.
It was noted that in this short time, students have shown signs of increased stress had similar problems in people who are prone to diabetes and had disorders of blood circulation.
These health problems are common in people who work in shifts as a program because their metabolism is disturbed and the body functions are themselves affected.