Work site analysis program for human factors
The objective of the work site analysis program is to conduct work site human factors-related analysis and highlight stressors in the workplace. The program is composed of the following four main steps :
• Step I: Collect data. This step is concerned with collecting information necessary for highlighting human factors-related hazards in workplace. Some of the sources for collecting such information are safety records, medical records, insurance records, and OSHA-200 logs.
• Step II: Conduct baseline screening surveys. These surveys help to highlight those jobs/tasks that put workers at risk of developing cumulative trauma disorders (CTDs). In situation when the job places workers at risk, there is absolutely a definite need for a program to require the human factors job hazard analysis.
The survey is carried out with a human factors' checklist containing elements such as materials handling, posture, and upper extremity factors. The basis for the hazards' identification is human factor risk factors such as job process, conditions of a workstation, or work procedure that directly or indirectly contribute to the risk of developing CTDs. Some of the CTD risk factors are excessive vibration from power-tools, prolonged static postures, cold temperatures, continued physical contact with work surfaces, improper tools, repetitive or prolonged activities, awkward postures of the upper body, and forceful exertions.
Similarly, the back disorder-related risk factors include poor grips on handles, prolonged sitting, bad body mechanics (e.g., continued bending over at the waist), lifting objects of excessive weights, and lack of adjustable chairs, body support, footrests, etc.
- • Step III: Conduct human factors job hazard analysis. This is concerned with conducting human factors-related hazard analysis of each and every job/task that puts employees/workers at risk of developing CTDs. This type of analysis is considered extremely useful for verifying lower risk factors at light duty/restricted activity work positions as well as for determining whether risk factors for specific work position have been minimized or eliminated altogether.
- • Step IV: Conduct periodic surveys and follow-up studies. These are basically concerned with conducting periodic reviews for highlighting factors/failures/deficiencies previously overlooked in work practices or engineering controls.
Symptoms of human factors-associated problems in organizations, identification of specific human factors-associated problems, and useful strategies for solving human factors-associated problems
Over the years, safety professionals have highlighted a number of symptoms of human factors-associated direct or indirect safety problems in organizations. Seven of these symptoms are as follows [11,12]:
- • Symptom I: Cumulative trauma disorders (CTDs). Some of the factors associated with CTDs are extreme temperatures, high levels of vibration and mechanical stress, a high level of repetitive work, greater than normal levels of hand force, and awkward posture. The degree of worker/employee exposure to factors such as these can be determined by observing the workplace as well as people/workers at work.
- • Symptom II: High absenteeism and turnover. The high degree of absenteeism and turnover in an organization/company can be an indicator of human factors-associated problems. More clearly, it may be said that persons/individuals who are uncomfortable on the job to the point of experiencing physical-related stress are more likely to be absent from work and leave their current jobs for less stressful ones.
- • Symptom III: Work-created changes. Past experiences over the years clearly indicate that workers tend to adapt to the workplace to satisfy their needs. The existence of large workplace adaptations, in particular the ones intended to lower physical stress, can indicate the existence of human factors-related problems. An example of these adaptations takes place when workers/ employees have modified personal protective equipment and added padding.
- • Symptom IV: Visible trends in injuries and accidents. By carefully examining items such as insurance forms, accident-related reports, OSHA-200 logs, and first aid logs safety professionals can establish the existence of trends. More clearly, a clear pattern or a high incidence rate of a certain type of injury normally is a good indicator of existence of human factors-associated problems.
- • Symptom V: Significant manual material handling. Generally, the activities that involve a lot of manual material handling have higher incidence of musculoskeletal-related injuries. Furthermore, musculoskeletal-related injuries increase quite significantly in situations where factors such as lifting objects from the floor, bulky objects, lifting large objects, and high frequency of lifting are present. All in all, companies/organizations where factors such as these exist have human factors-associated problems.
- • Symptom VI: High incidence of worker complaints. A high incidence of worker complaints concerning physical stress or improper workplace design can be a good indicator of human factors-associated problems.
- • Symptom VII: Poor quality. This can result from human factors-associated problems, for example, poor inspection.
By conducting a task analysis of a given job, the specific human factors-associated problems can be identified. The problems that can be identified through task analysis include the following :
- • Tasks involving potentially hazardous movements.
- • Tasks requiring unnatural or uncomfortable postures.
- • Tasks with a high fatigue factor.
- • Tasks with high potential for psychological stress.
- • Tasks involving excessive wasted motion or energy.
- • Tasks leading to quality control-related problems.
- • Tasks due to a poor operations flow.
- • Tasks involving frequent manual lifting.
- • Tasks that should be automated.
Finally, it is added that some of the methods used for conducting task analysis are measuring the environment, questionnaires and interviews, drawing or sketching, photography and videotaping, and general observation .
Over the years, professionals working in the area of safety have developed various human factors problem-solving strategies for conducting tasks such as standing for heavy lifting/performing work in one place or in motion, seated repetitive work with light parts, seated work with larger parts, work with hands above chest height, standing work, seated control work, and work with hand tools. Thus, human factors problem-solving strategies for each of these seven tasks are as follows [9,12,13]:
- • Task I: Standing for heavy lifting/performing work in one place or in motion. This type of task involves heavy lifting and moving materials in standing position and its associated common physical stress is muscle and back strains resulting from improper lifting. In this case, some of the human factors-associated strategies for improving work conditions include providing adequate room for facilitating lifting without twisting, minimizing manual carrying of heavy objects upstairs, minimizing manual lifting as much as possible by employing lifting and hoisting technologies, making proper personal protection equipment readily available, training workers/ employees in the proper application of lifting methods, and keeping floor clean and dry where materials are to be lifted to prevent slips.
- • Task II: Seated repetitive work with light parts. This type of task produces stress that generally leads to problems such as back, neck, lower leg, and shoulder pains. Some of the strategies for reducing these types of problems are to adjust work surface position or height; use ergonomics devices for adjusting the height and angle of work; incorporate other work tasks for breaking the monotony of repetition; use an adjustable chair equipped with hand, wrist, or arm support as necessary; use job rotation with workers rotating from one or more different jobs; and ensure the existence of sufficient leg room in regard to depth, width, and height.
- • Task III: Seated work with larger parts. Some of the problems associated with this type of task/work are related to areas such as posture, lifting, reach, and illumination. In this specific case, some of the human factors strategies for improving work-related conditions include using supplementary lighting at the workplace; using appropriate technology for lifting and positioning the work for easy access that does not need twisting, reaching, and bending; and using appropriate adjustable chairs and work surfaces.
- • Task IV: Work with hands above chest height. Although this type of task/work can be conducted by either standing or sitting, its associated physical stress includes upper body, heart, and neck strain. Some of the strategies for reducing these types of problems are minimize manual lifting by raising the work floor using lifts and other technologies, use extension arms/poles when it is impossible to raise the work floor, and when procuring machines, look for machines with easily accessible controls below the horizontal plane of an employee's shoulders.
- • Task V: Standing work. This type of task/work produces physical stress such as leg, back, and arm strains. Human factors-related strategies for improving work conditions include using adjustable machines and work surfaces for optimizing height and position, providing adequate space around machines for moving materials and ease of movement in servicing machines, and ensuring that in the procurement of new machines, there is a recess at the bottom for the feet.
- • Task VI: Seated control work. This type of task/work involves using items such as levers, buttons, knobs, and wheels for controlling a system, process, or piece of equipment. In this case, some of the human factors-related strategies for improving work conditions are to use devices that fully satisfy standards such as finger control systems not requiring more than five newtons (1.1 pounds) and hand levers not exceeding 20 newtons (4.5 pounds), use an adjustable swivel chair with inflatable back and seat support, position the control seat in such a way that an absolutely clear line of sight exists between the back and the individual controlling it, and provide comfortable locations for control devices.
- • Task VII: Work with hand tools. The usage of hand tools can introduce a variety of potential hazards, and the physical stress associated with the use of hand tools include muscle strains of the lower arm, wrist, and hand and carpal tunnel syndrome. Some of the human factors-related strategies for improving the associated work conditions are to select tools with enhanced gripping surfaces on handles, minimize stress on the hand by selecting tools that have thick handles, choose tools specifically designed for keeping hands in the rest position, and select tools with handles having oval-shaped section when no twisting is involved.