DEVELOPMENT OF DESIGN PRINCIPLES AND EVALUATION METHODS OF APPROPRIATE TECHNOLOGY MACHINES FOR AGRICULTURAL PRODUCT PROCESSING

• Main Author: Rahman, Taufik
• Format: Dissertations
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/86591
• Institution: Institut Teknologi Bandung

Appropriate Technology (AT) is technology that meets community needs, addresses community problems, is environmentally friendly, and can be easily utilized and maintained by the community. Additionally, it should produce added value from both economic and environmental aspects. The use of AT in communities is one of the Indonesian Government's strategies to increase productivity and add value to products, especially agricultural commodities. However, a problem arises because currently, not many AT designs consider the characteristics and capabilities of the users. Therefore, this research proposes a design principles and evaluation methods for AT machine design. This research focuses on AT agricultural product processing machines. The model was developed to solve AT design and utilization problems in society by paying attention to ergonomics and human factors, thereby increasing effectiveness and productivity. The first stage of the research involved model development using literature studies, interviews, and field observations. Field observations and interviews were conducted with AT users, with eight respondents participating in this stage. The goal of the field observations was to directly observe the practice of using AT in the community and to understand the obstacles faced by users related to AT design. The second stage involved data collection through distributing questionnaires aimed at identifying AT design factors. The research respondents for this stage included both AT designers and users, with a total of 221 respondents. Data processing was conducted using principal component analysis (PCA) and importance performance analysis (IPA) methods. The third stage involved evaluating the AT machines through subjective and objective usability tests. These tests used the system usability scale (SUS) questionnaire and experiments with an electroencephalograph (EEG) and heart rate monitor (HRM). As a result of direct observations in the field and interviews, seven general problems were identified in using AT machines: functional aspects, physical workload, technical issues, energy consumption, security, maintenance and repair, ease of use, and tool dimensions. The results of the PCA analysis produced six principles and 42 design indicators namely safety and error prevention, functionality and economics, user friendly, low physical effort, user compatibility, and perceptible information. The results of the IPA analysis indicate several areas for improvement in AT design. Prioritized improvements for AT machine design include the importance of having guidelines regarding use and safety, as well as the need for AT machine design to incorporate and emphasize safety features. The third stage of research is to evaluate the AT machine. The selection of AT machines for this evaluation was based on questionnaire interviews with experts. Factors considered that influence reusability include process stages (set up, operation, finish) and AT machines with different ergonomic levels (extruder type noodle printing machines, mini extruder type noodle printing machines, sheeting slitting type noodle printing machines). The experiment was conducted using a within-subject design with 22 participants. The EEG parameters evaluated included delta, theta, alfa, and beta waves, while the HRV parameters evaluated included root mean square of successive RR interval differences (RMSSD), standard deviation of the NN interval (SDNN), high frequency (HF), low frequency, and the LF/HF ratio. In addition to these physiological parameters, the study also conducted a subjective usability evaluation using the SUS questionnaire. The results of the usability evaluation are used to determine the AT design evaluation method and to determine sensitive and accurate physiological parameters in the evaluation of the AT machine. The EEG parameters used in this study, delta, theta, and alpha waves, showed significant differences between AT machines at the operation stage. In contrast, beta waves showed significant differences at the set-up stage. Delta waves showed fluctuations in average values , while theta, alpha, and beta waves showed a decrease in average values from machine 1 to machine 3. The usability of a product is generally characterized by an increase in theta waves, an increase in alpha waves, and a decrease in beta waves. HRV parameters, namely SDNN, RMSSD, LF, HF, and the LF/HF ratio showed variations in the increase and decrease in average values between each process stage (set-up, operation, and finish) between machines. However, only the LF/HF ratio parameter statistically showed a significant difference. The results of the SUS questionnaire showed that, subjectively, the mini extruder machine had the best usability, followed by the sheeting slitting machine and the extruder machine. Based on the results of this study, the evaluation test method on the AT machine based on physiology, namely with HRV and EEG, can be used in usability assessment with LF/HF ratio and alpha wave indicators.