This paper presents results of a study conducted to estimate lower back loadings in cart pushing and pulling. Experiments were conducted in the laboratory using a cart. Six subjects with different weights (ranging from 50 to 80 kg) were tested for three different pushing and pulling forces (98, 196 and 294 newtons), three different heights of exertion (660, 1090 and 1520 mm high) and two different moving speeds (1.8 and 3.6 km/h). It was found that, in general, pushing a cart results in lesser lower-back loading than pulling. Subject body weight affected the lower-back loadings more significantly in pulling (50% increase as body weight increased from 50 kg to 80 kg) than in pushing (25% increase). Handle height of 1090 mm was found to be better than other handle heights in pushing while 1520 mm handle height was better for pulling in reducing lower-back loadings.

Priority dispatching rules and shop load affect jobshop performance. This paper evaluates ten different priority dispatching rules with respect to six different performance criteria under light, medium and heavy shop loads. Simulation was used as a tool to determine the rankings of the dispatching rules for a given shop load and performance criteria. A comparative study was conducted to investigate the performance of these rules. Two rules, 'shortest processing time' and 'least work remaining'. performed well under criteria related to the processing time. It was found that the rules that perform well in average and r.m.s. tardiness perform poorly under percentage-of-jobs-late criterion. The experimental results are conveyed with critical comments on the performance of the dispatching rules under different loading conditions of the shop.

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The objective of this study was to evaluate five different lifting tasks based on subjective and biomechanical estimates of stress at the lower back. Subjective estimates were obtained immediately after the subjects performed the lifting tasks. Rankings for different tasks were obtained according to the perceived level of stress at the lower back. A biomechanical model was used to predict the compressive force at the L5/S1 disc for the weight lifted considering link angles for the particular posture. The tasks were also ranked according to the compressive force loading at the L5/S1 disc. The weight lifted in these tasks for obtaining the subjective estimate of stress was the maximum acceptable weight of lift (MAWOL). This was determined separately for each subject using a psychophysical approach. Subjective estimates of stress were obtained for infrequent lifting, specifically for a single lift, as well as for lifting at a frequency of four lifts per min. The results showed that a lifting task acceptable from the biomechanical point of view may not be judged as a safe or acceptable task by the worker based on his subjective perception. This may result in a risk of the worker not performing the recommended task or not following the recommended method.

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Final quality of products/services starts with suppliers in the supply chain. Problems can occur if suppliers do not deliver the quantities requested in full, on time, or buyers select suppliers solely on the basis of lowest price. Supplier selection has been studied for large businesses but not for very small (micro) businesses. Therefore, a survey was administered to micro-businesses to determine: what factors are important to micro-businesses in selecting suppliers and how satisfied they are with their suppliers. Factors included Brand Name, Consistency, Cost/Lower Price, Loyalty, Quality, and Warranty. Results indicated that none of the factors were unimportant. However, buyer satisfaction was found to be dependent on Quality, Brand Name, and the Length of Time of the Buyer/Supplier Relationship. Additionally, it was concluded that quality, along with complete, on-time delivery are key to buyer satisfaction and may help suppliers achieve preferred status with microbusiness buyers.

Review of literature In the USA, Emmanuel and Glonek (1974) introduced exercise as a part of a programme aimed at relieving physical stress in microscope operators at a semiconductor firm. However, lack of motivation from the microscopists meant that the exercise programme had to be discontinued before its possible beneficial effects could be assessed. Ostrom (1981) pointed out that "dynamic sitting", implying a change in posture every five minutes, is important for comfort and promoting good circulation. Sauter (1986) has suggested physical exercises for relieving or reducing musculoskeletal stress in VDT work. The predominant modes of interaction between office, managerial and technical workers, and computers are data entry, word processing, information retrieval and interactive communication. In data-entry work, information is keyed, often in a repetitive manner, according to a set format. This can result in discomfort in joints through repetitive and prolonged use of fingers, hands and wrists, which may lead to CT D (cumulative trauma disorder). "CT D is a collective term for syndromes characterized by discomfort, impairment, disability, or persistent pain in joints, muscles, tendons, and soft tissues with or without physical manifestations" (Kroemer, 1992). Reports of CTD, including carpel tunnel syndrome among VDT users, have been cited by other researchers also (NIOSH, 1992; Pot et al., 1987). LeGrande (1993) reported catastrophic occurrences of repetitive motion health symptoms and disorders among directory assistance operators of Communications Workers of America, all of whom were engaged in sedentary work. The 1992 survey indicated the following symptoms: hand and wrist pain, 73 per cent; numbness and tingling of fingers, 59 per cent; arm and shoulder pain, 78 per cent; neck and back pain, 86 per cent; and leg pain, 53 per cent. Some instances of carpel tunnel syndrome have been reported among computer keyboard workers in the USA (BNA, 1992). Sauter et al. (1991) reported high prevalence rates of musculoskeletal discomfort among 539 data-entry VDT users. Almost constant discomfort was reported for low back (33 per cent), followed by neck and buttocks discomfort (27 per cent each), and almost constant right shoulder discomfort (15 per cent). Lu et al. (1993a; 1993b) also confirm shoulder and neck areas to be major sites of discomfort. Other health complaints offered by VDT operators are headaches, stomach pain, ringing or buzzing in the ears (NIOSH, 1981) and skin symptoms (Stenburg, 1993). Past research has identified many factors, such as demographic, task-related, workstation-related, ergonomic, and psychosocial factors, associated with health complaints of employees engaged in sedentary work. Individual factors, such as age, gender, eye quality and work habits, may also have certain effects on the workers' performance and health (NIOSH, 1992; Asakura and Fujigaki, 1993; Berggvist and Knave, 1993). Asakura and Fujigaki (1993) found that the impact of office computerization on perceived job characteris...

“Safety is no accident.” It is not a coincidence that this slogan appears often in FAA literature, correspondence and advisory circulars. It is a frequent reminder to all of us that reliability and safety in aviation is a team effort and that all individuals are responsible for doing their part towards the maintenance of a safe flying environment. Presents aviation safety in the TQM framework of customer focus, continuous process improvement and total involvement. Identifies customers at various levels and illustrates, with examples, how continuous improvement occurs. Highlights the mechanism in place which helps ensure these improvements. Shows that total involvement yields safety, reliability and quality in the aviation services that we receive today. Discusses the presence and prevalence of TQM in various sectors of aviation and suggests that further continual improvements are still needed in today’s aviation.