Ergonomics_-_Case_Study

Identification of the causes and proposed solutions 1) “An old rock & roll tune blasted from the hi-tech sound system” – according to Dalton & Behm (2007), music has equivocal effect on cognitive performance, meaning that it can facilitate performance of tasks which demand concentration and attention on one hand (especially moderate/low volume), but to be as distracting as noise during comprehension tasks on the other. However, Dalton & Behm conclude that loud volume intensities, both noise (unwanted sound) and music impair human performance during simple vigilance tasks. Given this information it is possible to infer that the excessively high volume in the club might have had some effect on the waitress’/barkeeps’ vigilance and attention, which resulted in serving the wrong liquid to the customers. Solution: Reduce the DB of the music to the recommended threshold of 85, and hold regular inspections to oversee it is done. 2) “Aqua and red hues reflected in the polished chrome (highly reflective material) furniture” – Parsons (2000), in his review of environmental ergonomics principals, points out that light can affect human performance at general tasks, but stresses glare as the main cause of distraction. Some important parameters in that regard include the contrast between an object and its background, size of the object and luminance of the object. Faulty design of these parameters may result in disability glare and veiling reflections which also contribute to poor detail inspection ability. The Eko-Klene was the same colour as the water melon drink (pink) and when coupled with the colour of the lighting background (red) and the adverse effect it might have had on visual performance (waitress couldn’t discern fine details for example) one may assume that lighting design inside the club contributed to the disastrous outcome of the incident. Solution: To reduce glare by Lowering the luminance of the glare source; this could be done by using translucent filters (e.g. lamp shades) which would diffuse the light and make it less direct. Or it is possible to replace the furniture by one that is made of a less reflective material than chrome. 3) “As barkeeps do, he started mixing a batch of drinks” – increased chance of making an error when there are other bottles around which contain different liquids. Solution: Barkeeps should make every drink individually (hire more barkeeps if necessary), also there should be no other bottles used in the bar area which do not contain drinks, in addition to that, any bottle not intended for drinking purposes should be marked distinctively from other bottles to avoid confusion. 4) “The barkeep placed the bottle and a dozen shot glasses on the counter” – a common sense mistake, in order to save time the barkeep let the waitress to make the drinks, thus increasing again the chance of an error (perhaps the waitress lacks training of making beverages). Solution: The barkeep alone should make the drinks and not waitresses. 5) The dishwashing machine was designed to operate with a unique kind of dish soap” – this points to lack of flexibility in design, making it hard to use other less dangerous soaps. Solution: Possible solution to reduce risks concerned with hazardous liquids could be to use dishwasher that is based on different technology, e.g. steam. 6) Eko-klene was delivered in semi-transparent containers – increasing chances of confusing the substance with other liquids. Solution: To avoid confusion with other liquids the manufacturer should have delivered Eko-Klene in sealed non-transparent containers. 7) Ecolab (the manufacturer) “described the dishwasher soap and warned of the hazards of it, on a label, on the side of the bucket” – This kind of design could imply that the label is hard to see from different angles, hard to read for short sighted and dyslectic people and In general, there’s been a failure on behalf of Eko-lab to draw attention to the label. Solution: Braun & Silver (1995) have examined in their study the interaction of signal words and colours. They have found the highest levels of perceived hazard among the participants when signal words were presented in red. Furthermore, they have shown that words such as “DEADLY” evoked more hazard awareness when printed in red than other colours. In a second experiment they examined the effect of colour on compliance with printed warnings; the findings have shown that warnings printed in red resulted in higher proportion of compliant behaviour than other colours. Adams & Edworthy (1995) examined the presentation of signal words in warnings in different font sizes and when surrounded by red borders and its effect on perceived urgency. They have found that text size has the greatest effect on perceived urgency, followed by border width. They conclude that bigger text and thicker borders will produce higher level of urgency. In accordance with some of the above ergonomic principals it is possible to suggest a new label design for Eko-Klene which would be based on red text against a white solid background formatted in a relatively big font surrounded by solid red border. The label should be visible from all sides of the bucket (e.g. multiple labels). 8) “There were no poison labels or symbols, just text. Solution: To add a warning symbol to the text on the bucket. Relying on the recommendations of Easterby (1970), this should be done with the following principals in mind: Solid boundary for high contrast, simplicity - not to burden the perception abilities, closure - to produce effect of “wholeness” and symmetry to make recognition easier. In terms of actual design, Smith-Jackson, Tonya, Wogalter and Michael (2000) have shown that symbols of skull, prohibition (circle-slash), and shock symbols has elicited the top three hazard ratings among the participants. The above information provides us with clues as to how the warning symbols should look like on the Eko-Klene bucket. 9) The label on the bucket provided a telephone hotline instead of immediate actions to be taken in case of an accident – one may panic in case of an accident, lose eyesight or the ability of speech (in case of swallowing) and fail to dial the number or speak on the phone all together. Solution: The label, in addition to the hotline phone number, should also contain instructions on what to do in case of exposure and how to treat the exposed area until professional help arrives. 10) The cautionary literature sent by the company was dismissed by the staff. Solution: Wogalter, Barlow & Murphy, (1995) conducted a study which has shown that compliance to owner’s manual warnings depends on location and accessibility. Therefore the solution is to increase accessibility to the warnings and cautionary literature. One way to do it is placing warning placards on the walls of the kitchen and other visible places inside the bar. 11) The text on the label was printed in red against pink background (semi transparent bucket), making it less obvious and hard to read, and maybe disregard the red colour as indicator of danger. Solution: Manufacture non – transparent buckets in order to achieve higher contrast between the labels and their background. 12) The colour of the fluid is pink; the opposite of what might be expected from a highly dangerous product. Solution: Change the colour of Eko-Klene to a less pleasant one (e.g. black) to avoid confusion with other liquids. 13) Eko-klene was meant to be used exclusively in conjunction with the dishwasher, but the information regarding this fact was scarce and not going beyond the side label and the cautionary literature. Solution: Labels can be placed on the dishwasher also, indicating the connection between it and Eko-Klene. 14) Kitchen workers used to pour the liquid into the dishwasher manually. Bad design of the bucket with no check valve or other security mechanism, also, the dishwasher lacks security mechanism that might prevent the machine from working until properly fed with the fluid. Solution: Add a check valve to the bucket to prevent accidental spillage. Also, add security mechanism to the dishwasher that would prevent it from working until properly loaded with the fluid using the designated mechanism. Note on organizational safety culture The following sections (causes 15 – 21, save cause 20) are concerned with organizational safety culture which includes many little incidents based on attitudes, beliefs and values of the employees towards safety measures, hazards and regulations and which manifested in hazardous behaviours. Applying localized solutions seems insufficient; therefore it is important to track the root of the problem which may lie in the deeper structure of the safety culture. The solutions to these causes are mainly behavioural rather than purely administrative (although implemented conjointly). There are a few ways to improve safety culture: one of the models to do this was suggested by Geller (1994) and called TSC (Total Safety Culture). For instance, According to Geller, It is desirable to change the rhetoric of “regulations” to “company mission” achieved and practiced, by the employees – for the employees. This change can eliminate the perception of top-down control and facilitate motivation to demonstrate safer behaviours. Another principle may be to increase the sense of belonging to a group, thus increasing the level of active care for the group members but also outsiders. This could be done by decreasing the frequency of top-down directives, increasing team building – discussion groups, group goal-setting and feedback, celebrate positive outcomes and achievements of safety behaviours and reward employees for such behaviours. These solutions are designed to shift the organizational culture of safety from priority to value in itself. They are designed to establish consistent link between safety and all other job aspect like productivity, quality, efficiency and profitability. Thus, the administrative solutions, like training and structural changes should be implemented in conjunction with a wider intervention to change the organizational safety culture as a whole. 15) “Kitchen employees did not always wear gloves and goggles when handling the material, contributing to the impression that the fluid was not at all toxic” – poor training and discipline, managerial failure. Solution: Comprehensive training is needed for the stuff on topics of occupational health & safety and compliance to regulations. 16) “A few weeks before the accident regular liquid dish soap, ran out.” Solution: Administrative failure. The shortage should have been anticipated and refilled in advance. This could be prevented simply by tighter supervision of supplies. It is impossible to understand from the case what the administrative practices of the club were, but control over supplies can be improved by installing some kind of tracking system or appointing supplies manager. 17) “The dish soap never arrived” despite the requests of the employees – second mistake following the first one, ignoring the problem. Solution: The solution to this also may be borrowed from the previous one, as this would be the direct responsibility of supplies manager (see also note on organizational safety culture). 18) “The barkeep, faced with piles of dirty dishes, poured some of the Eko-klene into a bottle which had been normally used to mix drinks and took it back to the bar to wash the dishes with it”. Solution: forbid the use of drinking bottles for any other purposes other than drinking (see also note on organizational safety culture). 19) “The dishes had been cleaned like this for a number of weeks and no one bothered to notice”. This points to a lack of care and motivation to act safely. Solution: Introduce disciplinary sanctions if safety regulations are breached on one hand and reward for adherence to regulations on the other, (see also note on organizational safety culture). 20) On the night of the accident, someone put the bottle on the bar counter – the liquid inside the bottle was indistinguishable from the nearby cocktails, further more it didn’t have a strong odour suggestive of the of caustic cleaning fluid. Solution: Add strong repulsive odour to Eko-Klene. 21) The situation, after the customers had drank their cocktails was handled poorly. Not realizing the severity of the incident, the employees from the back of the bar told the waitress to “return the customers money, and keep quiet” instead of actively investigate and assist the customers, maybe even providing them with first aid until the ambulances have reached the scene. Solution: Train stuff in CPR. Conclusion The causes which have been identified here vary in nature, some are purely physical which require product/environment design oriented solutions, while others concerned with behavioural elements which constitute the wider notion of organizational safety culture. The solutions for both types of causes reflect the appropriate approach to be taken for each type and in some cases should be carried out conjointly and over time, as changing safety culture is a difficult affair. In conclusion, if adopted, in full or in part, the proposed solutions may significantly reduce and hopefully abolish altogether the chances of reoccurrence of similar disasters in the future. References • Adams, A. S. & Edworthy, J. (1995). Quantifying and predicting the effects of basic text display variables on the perceived urgency of warning labels: tradeoffs involving font size, border weight and colour. Ergonomics, 38(11), 2221-2237. • Braun, C. C. & Silver, N. (1995). Interaction of signal word and colour on warning labels: differences in perceived hazard and behavioural compliance. Ergonomics, 38(11), 2207-2220. • Dalton, B., & Behm, D. (2007). Effects of noise and music on human and task performance: A systematic review. Occupational Ergonomics, 7(3), 143-152. Retrieved from Business Source Complete database. • Easterby, R. (1970). The Perception of Symbols for Machine Displays. Ergonomics, 13(1), 149-158. • Hartley, L. & Williams, T. (1977). Steady State Noise and Music and Vigilance. Ergonomics, 20(3), 277-285. • Knave .B. Ergonomics and lighting, Applied Ergonomics, Volume 15, Issue 1, March 1984, Pages 15-20. • Michael S. Wogalter, Kenneth R. Laughery (1996). WARNING! Sign and Label Effectiveness. Current Directions in Psychological Science Vol. 5, No. 2, pp. 33-37. • Parsons K. C. (2000), Environmental ergonomics: a review of principles, methods and models, Applied Ergonomics, Volume 31, Issue 6, Pages 581-594 • Smith-Jackson, Tonya L.; Wogalter, Michael S. (2000). Users' Hazard Perceptions of Warning Components: An Examination of Colours and Symbols. Human Factors and Ergonomics Society Annual Meeting Proceedings, Proceedings 6 - Consumer Products, pp. 55-58(4). • Wogalter, M. S., Barlow, T. & Murphy, S. A. (1995). Compliance to owner's manual warnings: influence of familiarity and the placement of a supplemental directive. Ergonomics, 38(6), 1081-1091.