An integrated shipment planning and storage capacity decision under uncertainty: a simulation study

Purpose – In transportation and distribution systems, the shipment decisions, fleet capacity, and storage capacity are interrelated in a complex way, especially when the authors take into account uncertainty of the demand rate and shipment lead time. While shipment planning is tactical or operational in nature, increasing storage capacity often requires top management’s authority. The purpose of this paper is to present a new method to integrate both operational and strategic decision parameters, namely shipment planning and storage capacity decision under uncertainty. The ultimate goal is to provide a near optimal solution that leads to a striking balance between the total logistics costs and product availability, critical in maritime logistics of bulk shipment of commodity items. Design/methodology/approach – The authors use simulation as research method. The authors develop a simulation model to investigate the effects of various factors on costs and service levels of a distribution system. The model mimics the transportation and distribution problems of bulk cement in a major cement company in Indonesia consisting of a silo at the port of origin, two silos at two ports of destination, and a number of ships that transport the bulk cement. The authors develop a number of “what-if” scenarios by varying the storage capacity at the port of origin as well as at the ports of destinations, number of ships operated, operating hours of ports, and dispatching rules for the ships. Each scenario is evaluated in terms of costs and service level. A full factorial experiment has been conducted and analysis of variance has been used to analyze the results. Findings – The results suggest that the number of ships deployed, silo capacity, working hours of ports, and the dispatching rules of ships significantly affect both total costs and service level. Interestingly, operating fewer ships enables the company to achieve almost the same service level and gaining substantial cost savings if constraints in other part of the system are alleviated, i.e., storage capacities and working hours of ports are extended. Practical implications – Cost is a competitive factor for bulk items like cement, and thus the proposed scenarios could be implemented by the company to substantially reduce the transportation and distribution costs. Alleviating storage capacity constraint is obviously an idea that needs to be considered when optimizing shipment planning alone could not give significant improvements. Originality/value – Existing research has so far focussed on the optimization of shipment planning/scheduling, and considers shipment planning/scheduling as the objective function while treating the storage capacity as constraints. The simulation model enables “what-if” analyses to be performed and has overcome the difficulties and impracticalities of analytical methods especially when the system incorporates stochastic variables exhibited in the case example. The use of efficient frontier analysis for analyzing the simulation results is a novel idea which has been proven to be effective in screening non-dominated solutions. This has provided the authors with near optimal solutions to trade-off logistics costs and service levels (availability), with minimal experimentation times

Implementasi model pembelajaran kuantum berbasis quizizz untuk meningkatkan prestasi belajar PKN siswa kelas V semester II SD Negeri 2 Pangkung Karung

Penelitian ini dilaksanakan di SD Negeri 2 Pangkungkarung berlokasi di Kecamatan Kerambitan, Kabupaten Tabanan, Bali. Subjek penelitian adalah siswa Kelas V Semester II tahun pelajaran 2020/2021. Sedangkan objek penelitian adalah prestasi belajar PKN. Tujuan penelitian tindakan kelas ini adalah untuk mengetahui apakah penerapan model pembelajaran kuantum berbasis quizizz dapat meningkatkan prestasi belajar PKN peserta didik. Penelitian tindakan kelas ini dilakukan dalam dua siklus melalui tahapan-tahapan perencanaan, pelaksanaan, observasi/pengamatan, dan refleksi. Tes prestasi belajar merupakan alat yang digunakan dalam mengumpulkan data hasil penelitian yang selanjutnya dianalisis menggunakan analisis deskriptif. Kriteria keberhasilan penelitian adalah: (a) nilai rata-rata prestasi belajar PKN minimal stara dengan KKM=76 dan (b) ketuntasan belajar secara klasikal minimal 85%. Hasil yang diperoleh dari penelitian ini menunjukkan adanya peningkatan kemampuan peserta didik mengikuti proses pembelajaran dari rata-rata awal 64,82 meningkat menjadi 73,73 pada siklus I dan meningkat menjadi 81,91 pada siklus II. Sedangkan ketuntasan belajar awal 27% pada siklus I meningkat menjadi 73% dan pada siklus II meningkat menjadi 91%. Simpulan yang dapat diambil dari hasil tersebut adalah penerapan model pembelajaran kuantum berbasis quizizz dalam pelaksanaan proses pembelajaran mampu meningkatkan prestasi belajar PKN siswa Kelas V Semester II tahun pelajaran 2020/2021. This research was conducted at SD Negeri 2 Pangkungkarung located in Kerambitan District, Tabanan Regency, Bali. The research subjects were Class V Semester II students in the 2020/2021 academic year. While the object of research is PKN learning achievement. The purpose of this classroom action research is to find out whether the application of the quizizz-based quantum learning model can improve students' learning achievement in PKN. This classroom action research was conducted in two cycles through the stages of planning, implementing, observing, and reflecting. Learning achievement test is a tool used in collecting research data which is then analyzed using descriptive analysis. The criteria for research success are: (a) the average value of PKN learning achievement is at least strata with KKM = 76 and (b) classical learning completeness is at least 85%. The results obtained from this study indicate an increase in the ability of students to follow the learning process from the initial average of 64.82 increasing to 73.73 in the first cycle and increasing to 81.91 in the second cycle. While the initial learning completeness 27% in the first cycle increased to 73% and in the second cycle increased to 91%. The conclusion that can be drawn from these results is that the application of the quizizz-based quantum learning model in the implementation of the learning process is able to improve the learning achievement of PKN students in Class V Semester II for the 2020/2021 academic year

Analysis of Empty Containers Supplies in the Shipping Network: Case Study at National Shipping Company

National Shipping Company (NSC) is a national shipping lines servicing domestic routes and a logistic key player of sea transport in Indonesia. Focus of this research is to determine total containers inventory for all routes, containers safety stocks at primary ports as well as optimum empty containers reposition strategy based on market’s requirement, all with purpose to avoid potential empty containers shortage. Unbalanced container turnover between inbound and outbound is a global issue in the shipping industry. A very common method applied by shipping operators in balancing supply and demand is repositioning excess containers to deficit areas. Determination of total container inventory begins with the calculation of safety stock of container inventory in Surabaya and Jakarta as a demand location port. Main parameter forming the calculation model is forecast cargo at home base port per route, service schedule as well as swiftness of cargo stuffing and stripping. Furthermore, determining the best routes combination shall reduce amount of container inventory. Calculation model of producing total container inventory which should be provided in 2018 is 46,382 TEUs while total existing NSC’s inventory in 2018 is 48,567 TEUs. From the total existing inventory, 2,516 TEUs turned out to be inactive (idle) for more than 30 days, meaning the active ones were 46,051 TEUs. From this comparison, calculation model is able to describe existing condition at 99.3%. Using the same model, a change in route combination with a pendulum nusantara service was carried out, which resulted in 968 TEUs reduction of container potential and reduction of one vessel allocation. This leads to potential efficiency of IDR 40,624,648,190 (forty billion six hundred twenty four million six hundred forty eight thousand one hundred and ninety Rupiah) for operational of year 201

Re-Design Layout and Allocation of Raw Material Warehouses Using Simulation Methods to Minimize the Handling Cost from Port to Warehouses

The high cost of raw materials handling from the port to the warehouses at PT. Petrokimia Gresik has encouraged this research to find solutions to reduce costs in raw material unloading activities. The location of factories and raw material warehouses that are separated from each other, the number of warehouses that are not yet connected with conveyor belts as well as the diverse types of raw materials become its own challenges in operating unloading activities to be more efficient. The layout and allocation of raw materials in the existing warehouses creates high cost of raw materials handling because slow moving raw materials are close to the production location, while fast moving raw materials are far from the production location. In addition, the differences in the existing unloading methods also affect the cost of raw materials unloading, the use of vessel cranes and dump trucks will increase costs, otherwise the use of conveyor belts will minimize the cost of raw materials handling. This research is important to find the layout and allocation of raw materials that have the most efficient handling costs. The steps in this study include (1) data collecting and processing; (2) making conceptual and simulation models, (3) verification and validation tests; (4) developing alternative scenarios; (5) running simulations based on alternative scenarios; (6) comparing scenarios using anova test and cost and benefit analysis. The simulation is done using Arena 14.0 software. The simulation results show that the re-design layout and allocation of 5 warehouses in Factory 2A and Factory 2B is the best alternative scenario. This scenario is proven to be able to minimize the cost of raw materials handling with savings of Rp. 10.958.028.455 per year with an ROI of 108% and a Payback Period of 0,48 years

Design of Decision Support System in Selecting Cement Vehicles Based on Driver Performance, Expeditor Performance, and Waiting Time

Current logistics developments affect a process in any company using third party logistics. Third party logistics is a distribution service, warehousing carried out by third parties (outsourcing). Third party logistics in its business practices has been owned by many parties. PT Z is one of the companies engaged in the cement industry which has a lot of cooperation with third party logistics. PT Z has assessed the expeditor partners. The problem that occurs is the problem of each driver and expeditor in the field agreeing to the same. There are some expeditors who have good performance and vice versa. In the midst of tight business third-party logistics resulted in each expeditor competing with each other and providing the best service to his clients. This research makes a decision support system by examining aspects that make the consideration of the selection of drivers and expeditors to be used for the transport of cement in PT Z. The method used in this study is the analytical hierarchy process (AHP) according experts’ opinion in cement industry. Research uses decision support systems based on web information systems as an application method. This research can determine the choice of the driver and expeditor who has the best performance to carry out the cement transportation process at PT Z by considering the driver's waiting time. Drivers who have better results will get greater opportunities (priority) chosen to transport cemen

Pricing and Warranty Level Decisions for New and Remanufactured Short Life-Cycle Products

Remanufacturing has become more prominent as a recovery process to mitigate the massive disposal of short life-cycle product at its end-of-use. However, remanufactured product is often perceived to be inferior to new product, and it has lower value in consumer’s willingness to pay. To increase the perceived quality of the remanufactured product, manufacturer offers a warranty, since one of the three roles possessed in warranty is being a signal to product reliability. This paper studies the pricing decisions and warranty level decision for new and remanufactured products in a closed-loop supply chain consists of a manufacturer and a retailer. The optimization modeling is performed under Stackelberg game with manufacturer as the leader. We found that higher expansion effectiveness coefficient would increase the supply chain profit. Also, there is an interval of demand’s speed of change, where the total profit would be at its highest. The optimum warranty level can be achieved regardless the initial warranty level set at the beginning of retailer’s optimization. Furthermore, the remanufactured product’s wholesale and retail prices are influenced by the expansion effectiveness coefficient

Simulation of In Bag Fertilizer Loading Process In Port of Petrokimia Gresik to Increase Loading Rate

Pelabuhan Petrokimia Gresik is one of the element to support the goverment regarding to maintain stability of fertilizer loading speed. The issue that occurs at Pelabuhan Petrokimia Gresik is the low speed of loading of fertilizer in the bag for the past 4 years. The low speed of loading fertilizer in bag tends to affect its cost. This study aims to simulate the process of loading fertilizer in bag at the Port of Petrokimia Gresik in order to find out the factors which influence the speed deterioration of fertilizer bagging process and applicable alternative scenarios to improve the process of loading fertilizer in bag. Simulations were executed using discrete simulation methods. The results show that loading speed downturn are influenced by significant factors as follows: high loading preparation time at the dock, which consumes 29,35% of loading activity; the high loading time at the dock, which reaches 23,15% of loading activity; also the extensive duration of truck commute from the warehouse to the pier which utilizes 22,95% of loading activity. This study evaluate 7 alternative improvement scenarios. According to ROI perspective, it is preeminent to additionally put field internal control personnel at each shift when loading fertilizer in bag, which can increase the loading speed to 668,29 tons / day, of investment (ROI) of 68% will be obtained within 1 year and the payback period will approximately result in 0,60 years. The best scenario in terms of loading speed is to add internal control personnel and apply a new method of loading fertilizer using a sling bag with an increase in loading rate to 804.17 tons / day, following ROI value of 23% within one year and a PP value of 0.81 year