ISSN / EISSN : 1693-6590 / 2442-2630
Current Publisher: Universitas Ahmad Dahlan (10.12928)
Total articles ≅ 153
Latest articles in this journal
SPEKTRUM INDUSTRI, Volume 18, pp 121-132; doi:10.12928/si.v18i2.17601
Lighting is an important factor in working comfort. A comfortable workspace must meet good lighting requirements by the lighting standards of a workplace. Visual comfort at work is the result of applying ergonomic aspects to workspace lighting. The purpose of this research is to analyze ergonomically lighting in the workspace of the engineering faculty of Muria Suci University. The method used in this research is descriptive quantitative. Where the data collection of light measurement in the workspace is carried out at the hour (09.00-14.00 WIB). Then the data is processed using surfer software version 10 to determine the distribution of lighting. Testing is done by comparing the standardization table of lighting intensity levels based on SNI 03-6575-2001 standards. Risk data the visual comfort of the lighting at work is analyzed in terms of the level of lighting risk. The results of this study indicate that quantitative exposure risk, all work spaces of the Faculty of Engineering, Muria Kudus University does not eligible SNI 03-6575-2001. Meanwhile, based on the risk of qualitative lighting, administrative workspaces that have a low risk of visual comfort and industrial engineering study program workspaces have a high risk of visual comfort
SPEKTRUM INDUSTRI, Volume 18, pp 133-144; doi:10.12928/si.v18i2.17801
To meet customer demand, the company was faced with insufficient capacity problems caused by low efficiency and congestion on the assembly line. Recent data shows that there is an imbalance in the work process time between workstations. This study aims to solve these problems to achieve the desired capacity. The research begins by observing the operating time and collecting other data on the assembly line then analyzed and developed as a solution to these problems. The analysis results show that the assembly line has low line efficiency and the impact on the output target is not as expected. From the time observations made on the assembly line, it can be seen that the current line is inefficient and there is a bottleneck at some workstations. Ranked Positional Weight (RPW) was chosen as a line balancing method to solve the problem. RPW generates new work arrangements for each workstation that has relatively the same uptime. The results of the RPW method showed a significant increase in line efficiency, namely 75.03%, the smoothness index increased by 90.79%, and the balance delay was reduced by 90.52%. After the solution is obtained, a new layout is created to be used as a guide for rearranging the assembly line.
SPEKTRUM INDUSTRI, Volume 18, pp 183-194; doi:10.12928/si.v18i2.17824
Logistics service providers are the key stakeholder in Indonesian logistics activities that are growing significantly and face many challenges. In this research, a case study on a logistics service provider located in the city of Yogyakarta Indonesia is evaluated. The provider is currently experiencing rapid growth indicated by increasing delivery volume and scopes. However, optimal resource management has not been able to be adequately calculated, such as inefficient courier assignment and overloaded couriers' volume. Thus, this study aims to minimize total distances through optimal zone groups under several restrictions. An optimization approach is selected in this research by initially building a mathematical model using a standard form of linear programming. Then, the mathematical model is solved to generate minimum distances. The result indicated that the total minimum distances had been reached with considerable changes in delivery zone grouping, and the couriers' capacity was optimally utilized without overloaded capacity. These zone groups can be used as a reference for further research by taking into account some restrictions such as packages fluctuations as well as adding objective to minimize couriers' traveling time.
SPEKTRUM INDUSTRI, Volume 18, pp 167-174; doi:10.12928/si.v18i2.17918
PT.XYZ operates in the field of two-wheeled vehicle manufacturing. A product defect is produced in the design, namely scratch defect, which has an average defect percentage of 2.39%, which exceeds the Company's defect standard of 0.2%. This study aims to determine the factors that cause scratch defects and reduce scratch defects using the QCC method on the frame assembly line section. The research method is done with the stage starting from the problem identification stage to find out the problems that need improvement steps. Data collection techniques are done by conducting direct observations in the field and conducting interviews with related personnel as well as performing literature studies to learn the science of literature that has a direct relationship with the research topic. The problem formulation level is done to find out the main problems that are the source of the occurrence of defective products. Stages of activity collecting data obtained based on direct observation results and company defect data. The data processing stage was done using the QCC method with PDCA approach and using 5W + 1H stage for the repair process so that the defect value is 0.56%, in this case, there is a decrease in the percentage of a defect by 1.84% from the previous 2.39%. As well as giving a good quality influence on the products produced
SPEKTRUM INDUSTRI, Volume 18, pp 113-120; doi:10.12928/si.v18i2.17316
Industrialization development, which is being implemented in some areas, is increasing rapidly. There are over one hundred thousand construction companies in Indonesia. Thus, the risk of accidents in the construction field is also likely to increase. Moreover, Indonesia is one of the countries with the highest construction accidents according to ASEAN's accident rate. This will cost a significant loss. The Indonesian construction industry should conduct a more in-depth investigation into the problem so that improvements would significantly decrease the accident rate. This research aims to obtain the first modification of HFACS models to be implemented in the companies. Thus, it is expected that there is a correction to the dominant factor. HFACS model is an accident investigation method based on the human error factor. This research is generally divided into three steps. There are preliminary, data collecting, then conclusion and recommendation. Based on the explanation above, it is obtained that the development of the HFACS model is by adding the level of an external factor, which obtained 1,2% in the construction industry. Through the recommendation based on the result of this research, be expected that construction companies in Indonesia could make continuous improvements to reduce the accident
SPEKTRUM INDUSTRI, Volume 18, pp 175-182; doi:10.12928/si.v18i2.14393
Nata de coco is food made from coconut water waste which can be consumed and can help improve the digestive process. The results of fermentation at PT XYZ still contain damaged or moldy nata sheets. The purpose of this study is to identify the causes of nata sheet defects. The identification of production defects in this study uses a fishbone diagram. The results of this study show that the cause of nata de coco sheet defects is the quality of coconut water that is too old (contains oil), too young (does not contain minerals), too long exposure to open air (contaminated with other bacteria). So that the resulting starter seeds are not good enough. Other causes are because the tray used is not clean (still runny), the newspaper used is torn (wide open), shocks occur during fermentation, alkaline pH, fluctuating air temperature, the boiling process has not reached boiling point, and the amount of additional materials (ZA fertilizer and sugar) is not quite right.
SPEKTRUM INDUSTRI, Volume 18, pp 159-166; doi:10.12928/si.v18i2.18396
This research focuses to study the potential of energy auditing in university building following ISO 50001 Energy Management standard. The sample area is Faculty of Animal Science and Technology Building, Maejo University. The scope of area is a lecture building (building A) and conference building (building B). For energy indicators analysis is divided into three levels namely; organization level, system level, and equipment level. The results found that the sample building used 100% of electricity or about 166,041.66 kWh/year. The significant energy use (SEU) area was the air conditioning system that consumed the highest energy use about 38.33%, following by the lighting system, other systems, lift system, ventilation system and pump system which their proportion are 30.76%, 28.32%, 1.43%, 0.95%, and 0.21, respectively. The energy utilization index (EUI) before the study is equal to 5.49 kWh/m2∙year higher than after the study assessment that is equal to 3.75 kWh/m2∙year from four recommended measures for example; lighting bulb reducing in the brighter area than standard, changing the fluorescent bulb to LED bulb, changing air conditioning to use a high-efficiency air conditioner, and reducing time ventilation fans in the air-conditioned room. If the sample building will improve following recommended measures, the expected result is a great saving than the current situation. The energy performance index (EPI) of will be decreased by about 31.63%. The electricity will be saved of 32,239.38 kWh/year or equivalent to 125,088.78 Baht/year which the investment cost is about 682,075.00 Baht and get a payback period of 5.45 years.
SPEKTRUM INDUSTRI, Volume 18, pp 145-158; doi:10.12928/si.v18i2.17515
To maintain the performance to optimalization operating at Coal Fire Power Plant (CFPP) the reliability of power plant equipment needs to be maintained especially on critical equipment. Based on CFPP failure data during 2012 – 2017, one of the critical equipment is the Induce Draft Fan (IDF). The Journal will analyze the reliability, availability and maintainability for the IDF equipment with the approach of Life Cycle Cost Analysis (LCCA). Using the IDF equipment failure data during 2012 - 2017 which is processed using Minitab 17 application with Weibull Analysis method, the results obtained the mean value (µ) for MTTF and shape parameters (β) and scale parameters (η) for calculation MTTR. That data combined with the hours of annual routine maintenance periods for each unit, used to calculate the operating and maintenance (O&M) hours of IDF in a year and then combined with operational cost data so the total O&M costs for the IDF during 15 years period obtained. Consider with assumptions for the calculation, the final results can provide input for management to making appropriate maintenance decisions.Based on analysis data, MTTF and MTTR values for IDF 1A is 10,726.6 hours and 43.84 hours, IDF 1B is 4,891.07 hours and 5.35 hours, IDF 2A is 5961.44 hours and 75.45 hours, IDF 2B is 7,047.26 hours and 163.70 hours, IDF 3A is 5,059.77 hours and 220.86 hours then IDF 3B is 7,218.89 hours and 101.14 hours. The results of LCCA approach for 15 years obtained the lowest total maintenance cost is IDF unit 1 of 527.68 billion.
SPEKTRUM INDUSTRI, Volume 18, pp 195-202; doi:10.12928/si.v18i2.16967
Bonorowo land in Laren Subdistricts, Lamongan Districts, is one of the areas that uses its land for rice, corn and kenaf cultivation. The agricultural sector in Laren does not yet have a detailed economic analysis. Farmers ignore the importance of considering initial capital and some “small” costs in this activities. Therefore, in this study, the calculation of business feasibility was carried out on rice, kenaf, and corn farmer groups in Bonorowo land, West Laren. Business feasibility analysis is conducted through calculation of the value of NPV, IRR, and IP. The calculation system uses a Microsoft Excel spreadsheet formula. The NPV, IRR, and PI values of corn cultivation are Rp. 524,182.40; 144.43%; and 2,9. The NPV, IRR, and PI values for kenaf cultivation are Rp. 1,145,532.39; 266.43%; and 5.15. The NPV, IRR, and PI values for rice cultivation are Rp. -495,085.78; -25.18%; and -0.79. The results of the economic analysis of the cultivation of rice, corn, and kenaf in Bonorowo land, Laren Subdistrict, show that rice cultivation has caused losses and is not feasible to continue.
SPEKTRUM INDUSTRI, Volume 18, pp 103-112; doi:10.12928/si.v18i2.14957
PT. Trijaya Plastik Utama is a company that manufactures raincoats. Based on the results of interviews with workers in 3 production departments, most experienced complaints in the upper limbs, especially the neck, back, and hands. Most of the work does repetitive activities with long cycles, so the nature of the work is suspected to cause musculoskeletal disorders for the operator. This study aims to identify the presence of musculoskeletal risks due to repetitive work using the Occupational Repetitive Action (OCRA) method. Based on the identification results of each department section, the packing section has the highest OCRA index value with a value of 3.86 for the right hand and 3.01 for the left hand. Improvement efforts to reduce risk due to repetitive work is to apply the concept of Eliminate, Combine, Re-Arrange and Simplify (ECRS) and the proposed design of work facilities. As a result, the OCRA index value dropped to 0.95 for the right hand and 0.85 for the left hand where the conditions were optimal