Hospital is a community service center that has a vital role. Hospital activities related to human life make the hospital as a system that must provide excellent service for visitors (patients). In fact the excellent service is not easy to do because of the many components involved in the system. Components or variables in the system are prbabilistik or uncertain. To maintain the quality of hospital services, an action is needed to evaluate, analyze and improve the system, especially the service system for patients. Simulation is one of the tools that can be used to evaluate, analyze and test changes to the system to get better results. In this study, simulation will be carried out on the outpatient or polyclinic service system in RSUX using simulations with the help of software promodel. From the simulation results it is known that the simulation model is valid and can be used to evaluate the system. In this study, a trial was conducted to change the number of servers in the pricing section to obtain a smaller idle process.

Simulation is one of the tools to solve the problems in a system, including hospital systems. The hospital has objectives and entities that are different from other systems, namely service to patients (humans) primarily, so making some decisions requires consideration due to the complexity of the variables within them. This preliminary study will discuss what problems might occur in the hospital and how the application of the simulation in solving the problem. Based on observations and interviews conducted, it is known that there are four issues: 1.) hospital services 2.) labor allocation (nurses) 3.) capacity and number of rooms/beds 4.) drug supply. Based on the literature search results, it is known that the simulation has the ability to solve these problems. The results of this literature review will then be used as a basis for developing simulation models in hospitals which are the object of research.

Regional autonomy in Indonesia allows every region in Indonesia to manage its own finances. Each region shall be entitled to regulate their own locally-generated revenue, including taxes and user charges. One source of regional levies is from Public On-street parking. On-Street parking in Sleman Regency Yogyakarta has considerable potential. Sleman is a district with the largest population in DI Yogyakarta province of Indonesia. This is because most of the commercial, educational, health and employment centers are located in Sleman. There are several On-street parking centers in Sleman, and the most are in Depok District. So far, the parking retribution system of On-street parking is one of the sources of locally-generated revenue is to determine the value of certain contracts that must be paid by the parking operator to the government. The value of this contract is fixed monthly for one year and will be reviewed in the following year. The value of this fixed contract indicates the number and types of vehicles coming at that location are fixed every day. For example, if the parking rate of two-wheeled vehicles is IDR 1000 and the monthly contract value is IDR 400,000 then the parking location will only contain a maximum of 13 motorcycles every day. In fact, the frequency of vehicles and vehicle types is a variable that is probabilistic in nature. Therefore, this study will attempt to simulate the potential revenue of parking charges by entering on-street parking probabilistic elements. The result of this research is the combination and number of parking vehicles obtained from simulation result. This simulation model can then be used as a predictor of the potential revenue from on-street parking charge so that it can also be used to determine a more appropriate contract value policy.

The price of broiler chickens at the consumer level varies daily. The price can be very low or otherwise. The price has resulted from the imbalance between the availability of chicken from suppliers and the market demand. As a result, demand will also fluctuate because it is influenced by consumer purchasing power. When the price of live chickens is low, the carcass company will usually buy in large quantities and expect to sell them at a higher price. The problem arises when the chicken overstock company will risk product damage due to product buildup in the refrigerated warehouse, so rework is necessary. In this paper, we will be developed a multi-item inventory model that considers material prices that vary to time, probabilistic demand, and rework costs. The aim is to determine the right policy for controlling frozen chicken products' inventory to minimize losses and total inventory costs.  This model can evaluate the best time to order broiler chickens, how much to order, how long the interval between orders, and the optimal number of orders, resulting in minimum total inventory cost per period.  The model solution is carried out with an optimization approach based on the parameters that affect the model. A numerical example is given at the end of this paper for model validation and illustrates the model solving algorithm.

The government has initiated the accreditation of journals as publication media to improve the quality and quantity of research in Indonesia to have competitiveness against international publication media. As one of the scientific journals, the OPSI Journal has just received a Sinta 3 rating in journal accreditation. To improve the quality of the journal, it is necessary to evaluate the usability level of the OPSI Journal website so that the strategies that must be used in improving its quality can be identified. The usability level evaluation is carried out using the System Usability Scale (SUS), which has many advantages. The evaluation was carried out on users of the OPSI journal website categorized into four groups: reviewers, authors, editors, and readers. Based on the results of the research conducted, it was found that the highest usability value was in the author group, and the lowest was in the editor group.