Ergonomic design intervention for Pineapple Peeling Task in Small Fruit Processing Unit
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North east India is one of the largest producers of pineapples in the country and there are many small fruit processing units across the region that process pineapples during the harvest season. These units being labour intensive are a significant source of employment for the local population. But, the wellbeing of the pineapple processing workers as well as their productivity is highly compromised due to use of old traditional tools and techniques.Pineapple processing activities starts with the manual peeling task that is quite repetitive, time taking and laborious in nature. In spite of the various peeling related issues, the units adhere to these traditional peeling methods as they don’t find any solution appropriate to their context of use. If the workers are provided with a comfortable and effective peeling aid with the consideration of prevailing conditions of the small processing units, the solution would not only improve occupational health and efficiency of the workers; and productivity of the units but also encourage many other small and marginalised entrepreneurs to get into this business. The thesis looks into existing work process related to pineapple processing and associated physical and occupational issues including risk factors influencing productivity. This provides the basis for evolving a holistic process for design intervention to develop work methods, tools and equipment for pineapple peeling. The thesis is broadly divided into three parts. The first part discusses the assessment of the issues related to pineapple peeling task through observation and interaction with workers. During the visits, general working of the small scale units was observed and peeling related problems and hazards were found to be quite apparent. Since not much of work had been reported in the area from the perspective of occupational health issues, an effort was made to establish the prevalence of ergonomic risks using specific evaluation tools like body pain map, analog Borg’s pain rating scale, Quick Exposure Checklist (QEC), Rapid Upper Limb Assessment (RULA). More than three fourth of the workers reported of pain in at least one of their body parts. Higher QEC and RULA scores for a large number of workers indicated further investigations and changes in work method soon. Different risk factors like repetitive task, prolonged work period, insufficient rest breaks, awkward posture adoption, repetitive force application, etc. associated with pineapple peeling task, were also identified. Thus, various ways of reducing these risk factors were thought of and eventually, the issues were decided to be addressed through an intervention, mechanically, by designing a pineapple peeling equipment that reduced drudgery and improved the peeling task capability of the workers. The second part elaborates upon the process adopted for conceptualisation and realisation of the intervention which would not only solve the ergonomics issues but also addresses other issue which hinders the implementation and adoption of new interventions. The ergonomic issues related to peeling had been addressed from engineering perspective (better operation and output) as well as considering a holistic systemic perspective (considering social, economic, infrastructure related factors, etc.). The issues related to the system, its stakeholders and interlink between the key stakeholders was studied to identify the key requirements along with study of peeling solutions available in the market which could be broadly segregated into different categories. With an intent to provide a more acceptable solution to the target users, a support tool, based on Quality Function Deployment (QFD) approach, was used to decide upon the most appropriate category of pineapple peeling solutions for given context. While attempting the design of peeling aid, the structure and fundamental properties of the fruit was also considered. Eventually, the final specifications were formulate followed by concept generation. The concepts were screened on the preliminary criteria like effort requirement, peeling effectiveness, peeling rate and constructional simplicity. Through iterative process, the final design solution was reached at which conceived peeling the pineapple slices instead of peeling the whole pineapple in one go. 3-D modelling and design detailing was carried out and final proof of concept was generated to demonstrate the working in principle. An effort was made to ascertain if the solution addressed the issues and requirements of workers and entrepreneurs, the two main stakeholders of the system in consideration. The strategies of the development were significantly influenced by the limitations of investment capability, skills and knowledge of local workers to adopt to the ophisticated high end equipment. Thus, a simple mechanical device, which was easy to anufacture and maintain with local expertise and could be used by local work force, was considered. The third and concluding part reports evaluation of the ergonomic design intervention against key requirements of the workers and entrepreneurs which also validated the design process undertaken for the new intervention. Virtually simulated RULA assessment of the 3D model was done using Digital Human Modelling (DHM). The improved proof of concept was evaluated for its performance by the workers on NASA Task load Index (TLX) as well as Task Completion Time (TCT) of the workers was also determine to find the rate of peeling using the equipment. To get the feedback of the entrepreneurs, to assess the effectiveness of the solution, the working of the equipment in principle was demonstrated to them and all the relevant details i.e. price, dimensions, accessories details, material details,weight, etc. were provided to them. The entrepreneurs were then asked to rate the new intervention and their old peeling solution on the same key requirements which had been identified, initially, as the basis of the design specifications. Similarly, an effort was also made to validate the findings of the support tool proposed for deciding the most appropriate peeling solution category. The findings of these assessments and the future scope of work have been discussed in the final phase of the thesis.
Supervisor: Debkumar Chakrabarti