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PT. Bukit Baiduri Energi (BBE) is a coal mining company that utilizes hauling roads as the main infrastructure for material transportation. This study focuses on a 1.7 km road segment selected as the object of technical evaluation. The objective of this research is to analyze the effect of road geometry improvements on hauling time efficiency and equipment productivity. The method employed includes direct field measurements and calculations of operational parameters such as travel time, cycle time, and productivity. The results indicate that improvements in road grade reduced travel time from 10.13 minutes to 9.86 minutes. This reduction was followed by a decrease in cycle time from 16.29 minutes to 16.22 minutes. In addition, productivity increased from 65.4 bcm/hour to 66.69 bcm/hour. Also, improvements in curve radius and superelevation were implemented on the hauling road. These improvements resulted in a further decrease in travel time from 9.86 minutes to 8.6 minutes. Consequently, the cycle time also decreased from 16.22 minutes to 16.18 minutes. The productivity of hauling equipment increased from 66.69 bcm/hour to 67.02 bcm/hour. Overall, the evaluation of road geometry provided a positive contribution to operational performance. The productivity of overburden removal increased from 65.4 bcm/hour to 67.02 bcm/hour, representing an improvement of 2.48%.

The increasing demand for electrical energy in military education facilities necessitates an efficient, reliable, and sustainable energy solution. This research aims to design a Solar Power Plant (PLTS) system to meet the street lighting needs in the Wangi-Wangi Complex of the Indonesian Naval Academy (AAL). The research method used is quantitative descriptive with an engineering design approach thru the stages of site survey, collection of solar energy potential data in the Surabaya area, calculation of electricity energy needs, calculation of solar panel capacity, calculation of battery capacity, and design of battery connection configuration. The research results show that the energy requirement for street lighting is 1,920 Wh/day, sourced from 8 units of 20 Watt LED lamps with an operating time of 12 hours per day. Based on the average solar radiation potential in Surabaya of 5 kWh/m²/day, the designed system requires 3 units of 200 Wp monocrystalline solar panels with a total area of approximately 4.89 m². For energy storage, 4 units of Yuasa N200 12 V 200 Ah batteries are used, configured in a series-parallel arrangement, capable of providing an effective energy of around 3,600 Wh with an estimated operating time of 22.5 hours. The research results indicate that the proposed solar power plant design is feasible to implement as an environmentally friendly, efficient alternative energy source that supports the green defense concept in the AAL environment.

Sweet corn (Zea mays saccharata Sturt.) is an increasingly popular horticultural commodity in Indonesia, attracting both farmers and consumer. This study aims to evaluate the effectiveness of single‑micronutrient fertilizer Mn‑EDTA (12%) in enhancing the growth and yield of sweet corn (Zea mays saccharata Sturt.). The treatments consisted of control, standard NPK, 0.25 NPK, 0.50 NPK, 0.75 NPK, and 1.00 NPK. The experimental findings demonstrated that the application of single‑micronutrient Mn‑EDTA (12%) fertilizer had a highly significant effect on vegetative growth and yield components of sweet corn, with statistically higher values compared with the control treatment. In general, fertilizer dosages equivalent to 0.25–1.00 NPK produced greater plant height, stem diameter, leaf number, ear length, ear diameter, biomass weight, ear weight with husk, ear weight without husk, plot yield, and productivity than the control. The RAE calculation indicated that the fertilizer was effective when applied at dosages equivalent to 0.75 and 1.00 NPK. The highest effectiveness was observed at the 1.00 NPK dosage, with an RAE value of 101%. Notably, the application of Mn‑EDTA (12%) fertilizer at the 1.00 NPK dosage provided significant field effectiveness, as reflected by the RAE value of 101%. This result implies that the use of single‑micronutrient Mn‑EDTA (12%) fertilizer at the 1.00 NPK dosage increased yield by 1.01 times compared with the yield improvement obtained from the reference fertilizer relative to the control treatment.

The management of ethical drug inventory is a crucial aspect of supporting the smooth delivery of healthcare services in hospitals. Improper management of ethical drugs can lead to stockouts or overstock, which results increased operational costs and the risk of drug expiration. This study aims to analyze the inventory control of ethical drugs at RSUD Inche Abdoel Moeis Samarinda using the Economic Order Quantity (EOQ), Safety Stock, and Reorder Point methods. The data used in this study are the consumption of ethical drugs during 2024, obtained from the hospital’s Pharmacy Installation. The data analysis method involves calculating ordering and holding costs, determining the optimal order quantity using EOQ, and calculating Safety Stock and ROP to maintain drug availability during lead time. The results of this study indicate that the application of the EOQ method provides a more optimal and efficient order quantity compared to previous policies. Furthermore, Safety Stock and ROP calculations assist the hospital in preventing ethical drug shortages and creating a more structured ordering schedule. Thus, the implementation of EOQ, Safety Stock and ROP methods can improve the efficiency of ethical drug inventory management while supporting the continuity of healthcare services at RSUD Inche Abdoel Moeis Samarinda.

Coal stockpile volume measurement is an essential part of mining production control. This study aims to evaluate the calculation of coal stockpile volume using a Total Station (TS) at PT. Bukit Baiduri Energi, Kutai Kartanegara Regency, East Kalimantan Province, and to assess the accuracy and effectiveness of this method in operational activities. Data acquisition was carried out through direct field measurements using a Total Station with a detailed surface point survey method. The collected data were processed using Minescape 5.7 software to generate a triangulated surface model, and the volume was calculated using the Cut and Fill method. The results show that the Total Station method produced a stockpile volume of 21,069.15 m³ with a high level of accuracy due to direct field measurement. This method provides advantages in elevation data accuracy; however, it requires relatively more time and manpower during the data acquisition process. Based on these findings, the use of Total Station is recommended for stockpile volume calculations that require high accuracy, particularly for production evaluation and coal reserve reporting.

This study aims to analyze the workload of sewing operators within a single production line and to equalize the workload using the line balancing method at PT. Pan Brothers. The garment industry requires high production efficiency; therefore, balanced workload distribution among operators is necessary to ensure optimal production processes. This research used an observational approach with data collection through direct observation of the sewing process, literature study, and documentation of production data. The research population consisted of 36 operators on the observed production line, analyzed through time study activities. The analyzed data included cycle time, takt time, and work processes at each workstation. The results showed that several processes had cycle times exceeding the takt time, specifically in processes number 2, 5, 6, 12, 17, 23, and 26, which caused bottlenecks and workload imbalance among operators. The calculation results indicated that the actual process time reached 520 seconds per product, while the ideal time based on takt time was 287 seconds per product, resulting in a time difference of 233 seconds or about 44% longer than the standard time. The implementation of the line balancing method was carried out by redistributing work elements from processes with high workloads to processes with remaining work capacity. The improvement results showed that the workload among operators became more balanced, the production process became more efficient, and the potential for bottlenecks could be minimized, enabling the company to achieve its production targets.

Ineffective spare part inventory planning may lead to supply delays and reduced compliance with lead time supply key performance indicators (KPIs). This study aims to implement the Collaborative Planning, Forecasting, and Replenishment (CPFR) method in spare part inventory planning at PT XYZ and to compare lead time supply performance before and after the implementation of the CPFR method. This research utilizes spare part usage data from January to June 2025, focusing on fast-moving spare parts. Demand forecasting is conducted using an error forecasting approach with the moving average method. Forecast accuracy is evaluated using the Mean Absolute Deviation (MAD) and Mean Absolute Percentage Error (MAPE). Furthermore, inventory planning is carried out through the calculation of safety stock and reorder point (ROP) as the basis for determining replenishment decisions. The results indicate that the simulated implementation of the CPFR method provides a more structured and anticipative inventory planning process. The comparison of performance before and after the application of CPFR shows an improvement in lead time supply compliance with the established KPIs. Therefore, the CPFR method has the potential to support improved spare part inventory planning performance at PT XYZ.

One of the risk impacts of blasting activities is flyrock. The impact of flyrock can be minimized by evaluate the factors that influence flyrock such as blasting geometry. Flyrock cannot be completely eliminated but flyrock distance can be reduced to prevent damage. This study aims to determine the actual maximum flyrock distance in the field and the factors that influence the flyrock distance. This study was conducted at PT. Sims Jaya Kaltim, Paser Regency, East Kalimantan Province. This research was conducted 31 times and the average throwing distance was 79.8 meters, the actual maximum flyrock throwing distance was 134.3 meters and the minimum throw was 40.5 meters. In the flyrock throw prediction, the Richard & Moore calculation method was used with a face burst mechanism of 121.3 meters and cratering of 232.2 meters and the Ebrahim Ghasemi dimensional analysis method of 104.5 meters. From both methods, the Ebrahim Ghasemi method was found to be closest to the actual flyrock with a standard deviation of 29.49 meters and an error percentage of 2.90%. From the results of the correlation between the blasting parameters and the actual flyrock, it was found that the factors that influence the occurrence of flyrock are powder factors, so an analysis was carried out to obtain a maximum flyrock throwing distance of 90 meters so that the safe radius of the tool is 180 meters, then the maximum powder factor used is 0.14 kg/m3.

This study aims to redesign the raw material yarn warehouse layout at PT. XYZ using the Class Based Storage method to improve storage and retrieval efficiency. The main problem identified in the warehouse is random item placement, resulting in relatively long retrieval times of approximately 10–15 minutes per pallet. This research applies a descriptive quantitative approach using a case study method. The data used consists of inbound, outbound, and inventory records of yarn raw materials from November 2024 to April 2025. The analysis was conducted using the FSN (Fast Moving, Slow Moving, and Non-Moving) method through the calculation of consumption rate and average stay, combined with ABC classification to determine storage priority. The results show that 9 types of yarn are classified as Class A, 11 types as Class B, and 11 types as Class C. Based on this classification, a new warehouse layout was designed by placing Class A items near the input-output area, Class B items in the middle area, and Class C items in the back area of the warehouse, thereby improving storage efficiency and reducing retrieval time.

This study aims to redesign the raw material yarn warehouse layout at PT. XYZ using the Class Based Storage method to improve storage and retrieval efficiency. The main problem identified in the warehouse is random item placement, resulting in relatively long retrieval times of approximately 10–15 minutes per pallet. This research applies a descriptive quantitative approach using a case study method. The data used consists of inbound, outbound, and inventory records of yarn raw materials from November 2024 to April 2025. The analysis was conducted using the FSN (Fast Moving, Slow Moving, and Non-Moving) method through the calculation of consumption rate and average stay, combined with ABC classification to determine storage priority. The results show that 9 types of yarn are classified as Class A, 11 types as Class B, and 11 types as Class C. Based on this classification, a new warehouse layout was designed by placing Class A items near the input-output area, Class B items in the middle area, and Class C items in the back area of the warehouse, thereby improving storage efficiency and reducing retrieval time.

Pyrolysis is a biomass conversion method into fuel through heating at high temperatures under oxygen-limited conditions. The main factors influencing the pyrolysis process include temperature, residence time, pressure, particle size, reactor design, and the type of pyrolysis employed. This study aims to design an auger-type fast pyrolysis system based on previous research. The design and modeling of the fast pyrolysis equipment were carried out using Autodesk Inventor 2021 software. Based on the calculation and design results, a fast pyrolysis reactor with a multi-stage configuration and a capacity of 5.2 kg was developed. The system consists of a three-stage reactor made of Stainless Steel 304. The reactor is equipped with a screw conveyor for material transport, which is driven by an electric motor. Biomass heating inside the reactor is provided by a clamp heater with an electrical power requirement of 611 W, while biomass cooling is performed using a condenser with a cooling water capacity of 15.586 liters. Based on the structural simulation results, the maximum von Mises stress obtained was 35.4 MPa, the maximum displacement was 0.0528 mm, and the safety factor was 6.07 under loading conditions including an internal reactor pressure of 0.32 MPa, a torsional moment of 1,130 kg·mm, and an operating temperature of 700 °C. These values are within the allowable limits of the material, indicating that the designed reactor is structurally safe and feasible for use.

The lack of a systematic calculation approach makes it difficult for APR Nine to monitor fabric raw material inventory, resulting in raw material purchases still being based on habit and intuition. With a total inventory of 2,001 rolls and raw material usage of 1,803 rolls of fabric, there were seven times of excess stock and five times of shortage during the period of October 2024 to September 2025. The difference between the two was 198 rolls. This study uses the Economic Order Quantity (EOQ) method to analyze fabric raw material inventory control. This study uses a quantitative approach with descriptive analysis using data from the period of October 2024 to September 2025. The results of the study indicate that 1694 orders with an ordering frequency of 10 times, a safety stock of 29 rolls, and a reorder point of 35 rolls are the ideal quantities when using the Economic Order Quantity (EOQ) approach. Compared to the previous APR Nine approach, the application of the Economic Order Quantity (EOQ) method is more effective in reducing overall inventory costs from Rp. 5,011,949.35 to Rp. 4,508,824.67.

MSMEs Traditional culinary MSMEs play a vital role in the Indonesian economy through job creation, income equality, and preservation of local culture. However, limited capital, raw materials, and labor, as well as unsystematic production planning, mean that MSME production decisions are still intuitive, leading to inefficiencies and suboptimal profits. A case study of MSME Sostang Tijang Bruno, a Sundanese cireng producer, shows that cireng production is still based on experience without clear calculations, resulting in a mismatch between production and demand and waste of raw materials. This study aims to optimize cireng production volume using the Graphical Linier Programming method to maximize profits by considering constraints on raw materials, working time, and market capacity. Data were obtained through observation, interviews, and documentation. The decision variables were the production volume of original chicken-filled cireng and spicy chicken-filled cireng. The analysis results showed an optimal production combination of 2.93 kg of original chicken-filled cireng and 0.53 kg of spicy chicken-filled cireng with a maximum profit of Rp499,000 per day. This method is expected to help MSMEs make more efficient and rational production decisions

The implementation of the Health Workload Analysis (ABK Kes) method reveals both strengths and weaknesses, particularly regarding the suboptimal execution of core tasks such as filing and distributing medical records. This study aims to compare the workload of health human resources (SDMK) between primary and advanced healthcare facilities—specifically Banyudono 1 Public Health Center and Indriati Boyolali Hospital—both of which have implemented hybrid medical record systems. Using primary data collected through interviews and observations and analyzed via the ABK Kes method, the results indicate a need for 10 additional staff members in the Casemix Unit at Indriati Boyolali Hospital and 2 additional medical record practitioners at Banyudono 1 Public Health Center. The Available Working Time (WKT) at the Public Health Center was set at 75,000 based on the Minister of PAN-RB Regulation No. 1 of 2020, whereas the Hospital used real-time calculations. While the Public Health Center aligns its policies with Ministry of Health Regulation No. 19 of 2020, the Hospital adjusts its staffing needs based on the ABK Kes results. Given that this method focuses primarily on quantity, future research and development (R&D) should integrate Lean Thinking for process analysis, ABK Kes for capacity, Queueing Theory for dynamic analysis, and NASA-TLX for psychological evaluation to provide a more holistic assessment of staffing needs.

This study aims to analyze the inventory management practices of qurban cattle at Purnomo Sapi Mulyo Farm in Boyolali, Central Java, particularly in facing the surge in demand prior to Eid al-Adha. The research is motivated by the unique characteristics of qurban cattle inventory, which involves living assets, seasonal demand, and biological risks that differ significantly from conventional inventory management. A qualitative descriptive approach with a case study design was employed to capture in-depth information regarding inventory planning, procurement, storage, and sales practices. Data were collected through in-depth interviews with the business owner as the key informant, direct observation of operational activities, and documentation review. The findings reveal that inventory management at the farm is conducted in a responsive manner based on consumer orders, enabling the business to minimize overstock risks and operational costs. However, inventory recording remains manual and unstructured, potentially limiting the accuracy of cost calculation and long-term planning. Price fluctuations and supply availability are strongly influenced by the Eid al-Adha momentum, while cattle health and lead time are critical factors affecting inventory effectiveness. From a theoretical perspective, the study extends inventory management concepts to the context of live and seasonal inventory. Practically, the findings suggest that implementing a simple yet structured inventory recording system could enhance operational efficiency and decision-making accuracy in local qurban cattle farms.

Problems in the transmission box of the Drilling Machine 438-02-814-0925 type (0.75 HP, 230/400V, 1425 rpm, produced in 1988) are the degradation of mechanical components for the pulley, V-belt, and rolling bearing. The purpose of maintenance and repair planning is to obtain maintenance costs, maintenance schedules in the period 2026, and the ratio of maintenance costs to profits. The maintenance and repair planning method includes collecting previous maintenance data; application of the inspection-replace-repair-overhaul (IRRO) method; evaluation of the working conditions of components, especially on the pulley, V-belt, spindle pulley (driven pulley), and rolling bearing; prediction of component service life; prediction of repairman costs; prediction of supporting equipment that will be used in maintenance; prediction of spare part replacement time or reinstallation of components after repair; estimation of maintenance and repair costs in 2026; and calculation of the ratio of maintenance costs to profits. The results of maintenance and repair planning obtained maintenance costs in 2026 amounting to Rp 4,627,000 with an estimated Drilling Machine rental rate of Rp 75,000/hour which has the opportunity to be rented for 400 hours/year, and a maintenance cost to profit ratio of 15.42% which implies that the Drilling Machine still has the opportunity to generate profits and is suitable for use in the coming years.

Learning is the process of children getting to know knowledge that aims to increase knowledge as a basis for forming behavior. The learning process is carried out so that children experience behavioral changes and gain an overall improvement in knowledge, skills, and attitudes. Learning is very closely related to daily life, therefore it is important for children to learn continuously, one of which is through learning mathematics. Mathematics learning has a very important role in the sustainability of children's education because mathematics is one of the fundamental non-physical tools in the world of education and daily life. Through mathematics learning, children are trained to think logically, systematically, critically, and creatively in solving various problems. In addition, mathematics helps children solve calculation problems that are often encountered in daily activities, such as counting money, measuring length, time, and distance, and interpreting simple data. Mathematics learning also plays a role in developing the ability to reason and make appropriate decisions. Therefore, mathematics learning is a subject that must be followed because it has a great influence on thinking skills, learning independence, and children's readiness to face life challenges and scientific development in the future.

This study addresses the urgent need for digital transformation at Percetakan Rajawali, a printing company currently reliant on manual order processes, which leads to service delays, recording errors, and lack of transparency. The research aims to design and implement a web-based online ordering information system to facilitate customer orders, accelerate confirmation and order tracking, and improve the efficiency of order data management. Adopting the linear and sequential Waterfall methodology, the study progressed through stages of system analysis, design, coding, testing, and maintenance. The key findings include the successful design of a comprehensive system featuring product catalogs, an online ordering module with real-time cost calculation, integrated payment management, and an admin dashboard for order processing. The system is designed with user-centered and secure principles, expected to significantly enhance operational efficiency, service speed, and customer satisfaction by providing an integrated, transparent, and accessible online ordering platform.

The calculation of work volume and construction costs is a fundamental aspect of project management, as errors in the estimation process can directly affect the preparation of the project budget. Many projects still use conventional methods for estimation, which are based on 2D working drawings with the assistance of Microsoft Excel, as seen in the Sungai Raya Religious Court Building project. This method is considered prone to calculation errors and less efficient due to the considerable amount of time required. With the advancement of technology, Building Information Modeling (BIM) has emerged, enabling automatic and integrated calculation of work volumes and construction costs through a three-dimensional digital model. This study aims to examine the implementation of BIM in the Sungai Raya Religious Court Building project and to compare the results of work volume and construction cost calculations between the BIM method using Autodesk Revit and the conventional method based on the project’s Bill of Quantity (BoQ). The research method was conducted by modeling the structural elements of the building, including pile caps, tie beams, columns, beams, floor slabs, and reinforcements. The results of work volume and construction cost calculations obtained from Autodesk Revit were then compared with the project’s BoQ as the conventional method. Based on the analysis, an average difference of 6.3% in work volume and 5.6% in construction cost was found, with the Autodesk Revit calculations showing slightly lower values compared to the project’s BoQ.

Improving service quality is a primary priority in hospital management. Service quality can be improved by reducing the percentage of non-value added activities through the Lean Hospital approach. This study aims to identify activities and analyze the root causes of critical waste in the drug distribution and utilization processes at the Outpatient Pharmacy Installation of Karanganyar Regency Hospital. This study is a non-experimental research with a qualitative descriptive design. Critical waste was obtained through the distribution of a waste weighting questionnaire assessed by all personnel involved in the drug distribution and utilization processes. The results show that the Value Stream Mapping calculation for the drug distribution process obtained a lead time of 147.41 minutes and a VAR value of 36%, while in the drug utilization process, compounded prescription service obtained a lead time of 128.53 minutes and a VAR of 24%, and non-compounded prescription service obtained a lead time of 75.8 minutes and a VAR of 26%. The critical waste questionnaire calculation using the Borda method in the drug distribution process showed overproduction 60%, inventory 53.33%, and waiting 43.33%, while in the drug utilization process, waiting 43.75%, overproduction 42.85%, and defect 39.70%. The 5S method, a Lean method, was used to eliminate waste in the service process at the Outpatient Pharmacy Installation of Karanganyar Regency Hospital.