A Fuzzy Logic Approach to Evaluate Discomfort of Body Parts Among Female Sal Leaf Plate Makers in India

Abstract

The commonly used ergonomic posture analysis tools are unable to measure exact level of risk associated with human body parts, since these tools exclude several factors, such as uncertainties in the border regions between adjacent ranges of inputs, design of work places, characteristic of works, etc. To capture those uncertainties, a computational methodology is developed for evaluating discomfort level of body parts among the female Sal leaf plate makers using the Mamdani fuzzy inference system. The modified Nordic questionnaire is used, subsequently, to measure consistency in collecting responses from the workers. The body part discomfort (BPD) scale is considered for subjective validation. The scores achieved from BPD scale and rapid entire body assessment worksheet are used to act as the input values of the proposed system. Due to some unavoidable imprecisions associated with the collected data, the membership functions of the input and output variables of the developed fuzzy system are represented by linear type fuzzy numbers. To show feasibility and reliability of the proposed methodology, a comparison is made between the achieved results and the scores obtained through fuzzy decision support system using rapid upper limb assessment.