General systems and operations design Essay

The human-system design should be least complicated and easy to operate and maintain. Less complications and operational requirements would mean minimum training requirements and workload for the people and thus, less error potential. Hardware operations and computer procedures should also be standardized so that similar operations would require similar hardware and similar applications would only require similar uses and procedures. Operations should only be standardized and implemented to minimize the number of required tools as well as human errors from improper training and minimum skill. Also, the minimization of maintenance requirements and the standardization of procedures and operations should be done so that any person involved in the exploration would at least have an idea on the operations which is especially necessary in cases of accidents when a company in space becomes incapable of operation (Man-Systems Integration Standards, 2006). Changes in Anthropometry As people travels farther from Earth, there is the loss of gravitational pull. This loss, together with the changes in environment exert great effects both in the anthropometry and biology of humans and thus requires extensive consideration especially in designing workstations. In particular, the human body size and posture, the surface area, the movement and volume as well as the mass considerably change with the absence of gravity (Vogel, 1976; Man-Systems Integration Standards, 2006). The height of a person generally increases for both short and long-term missions (Sinha, 2002; Vogel, 1976). This is caused by spine lengthening which can vary from 0.5 inch to about 3% of the baseline height prior to the mission. The fluid shifts caused by gravity cause changes in the chest, waist and limb-circumferences, usually a decrease (Man-Systems Integration Standards, 2006). Because weight is a function of gravitational force, the weight of a person decreases from 3-4%, most of which because of water, and loss of lean body mass as well as fat. Metabolic changes that happen further throughout the mission also cause further weight loss while the center of the weight becomes the head (Man-Systems Integration Standards, 2006). Pre-operation anthropometry does have an effect on how much increase or decrease will happen with the decrease in gravitational pull. This means that in general, sex and race could also have an effect on the amount of changes that would happen as a result of the decrease in gravity. People from the West are usually taller compared to their Eastern, Asian counterparts. In addition, males are generally taller compared to the females of the same race (â€Å"Man-Systems Integration Standards,† n. d. ). The anthropometric data are usually used in the design of equipment. The equipment to be used must be able to fit to any user regardless of size. This is done by designing a one-size-fits-all principle, to accommodate all possible users. This is especially applicable to the design of chairs and the dimensions of the window. Equipment sizes can also be tailored to fit a specific user so long as he or she would be the only user. Objects that must be reached such as buttons and switches must be adjusted based on the reach of the shortest person. In addition, the fact that the spine lengthens while in space would affect the placement of reachable objects. Because the spine lengthens, there would be an increased or easier overhead reach while the downward reach becomes more difficult because of decreased assistance by gravity (Man-Systems Integration Standards, 2006). The anthropometric data can also be used in the design of clothing. Since height increases generally happen as a result of the increase in spin length while in space, the designers must tailor the space suits to accommodate such changes (Man-Systems Integration Standards, 2006). In addition to gravity, the actual tasks that must be performed in space are considered in the design of equipment. To exemplify, if the task involves great precision, continued operation and the use of two hands, the task should be as close as possible to the operator. For tasks that require the use of special suits, design reach dimensions are generally reduced (Man-Systems Integration Standards, 2006). Changes in Work Capacity and Biology The lack of gravity also forces design changes particularly in objects that require pushing, and pulling. Because there is lack in gravity, human force is basically reduced. Diminished musculoskeletal strength and reduced cardiac capacity are effects of lack of gravity and can affect work performance and capacity (Miller, n. d. ). It follows then that in functions that require force such as pushing and pulling, there should be mechanical assistance in the forms of body restraint systems that could substitute for gravity. These restraint systems must be developed under neutral buoyancy conditions on Earth or in actual conditions of the space. Handhold, waist and foot restraints can be used for holding onto a handgrip to accommodate functional reaches; waist restraint for good body control; and foot restraint if the need is excellent reach performance, stability and control (Man-Systems Integration Standards, 2006). Gravity could also have a significant effect on a person’s biology. Particularly, the reduced gravitational force could induce spatial disorientation and space adaptation syndrome or space sickness (Ercoline, 1994). Such are not considered positive effects because they cause impairment of performance. Spatial disorientation refers to changes in posture, vertigo and illusions of movement that could result to tumbling (Brown, 2000). Critical activities are not advised to humans on mission when they are spatially disoriented. In the first days in space when humans experience space adaptation syndrome, humans tend to limit head motions. The effect is increased task time. What is usually done at this point is having limited activities that require speed (Man-Systems Integration Standards, 2006). As implied earlier, gravity also has effects on the human muscular and circulatory system. The effects of diminished gravity on humans’ exercise capacity as a result of reduced cardiac activity (Davis, 1999; Bungo, 1983) and muscular strength (Patton, 1987) necessitates countermeasures such as diet plans and exercise plans (Man-Systems Integration Standards, 2006). One thing that must be considered by the space industry is the adjustment of the human circadian rhythm and the effects of such adjustments in human performance (Gander, 1989). As it is, the goal of human factors research is to effect easier conditions in the space so that better and more successful performance is expected. Failure to do so would mean a loss in life and loss in significant investments (Man-Systems Integration Standards, 2006). Another thing that humans involved in space missions experience is great acceleration and vibration. Acceleration affects the vision depending on how its force is directed. The usual results are dimming of vision, loss of vision at a certain side, usually the periphery, and diminished, blurred or doubled vision. This restriction in vision could induce motion sickness which could affect performance (Stern, 1990). Vibration also has a degrading effect on the performance. It is usually during the lift-off and landing when vibration is greatest. Unfortunately, there are many times when vision is very important. Because of this, letters on equipment and signs are usually written in large format so as to accommodate any blurring or degrading effect of vibration on the person’s vision (Man-Systems Integration Standards, 2006).