Inventory models with integrated time dependent demands for deteriorating items – in third and fourth order equations.

. Inventory models with integrated time-dependent demands for deteriorative items are considered in this study. The demand models found in the literature include constant, linear, quadratic, exponential, price dependent, and stock dependent among others. To wit, no study exists that uses integrated time-dependent demands. Three models are developed: The first model uses continuously compounded demands, the second model uses linear demands integrated with continuously compounded demands, and the third model uses quadratic demands integrated with continuously compounded demands. Mathematical models are delineated for each model and relevant examples are provided to elucidate the proposed procedure. The objective herein is to obtain optimum order quantities and order intervals concerning the overall cost. Sensitivity analysis is provided for each of the three models. The necessary data was generated using Visual Basic 6.0.. Inventory models with integrated time-dependent demands for deteriorative items are considered in this study. The demand models found in the literature include constant, linear, quadratic, exponential, price dependent, and stock dependent among others. To wit, no study exists that uses integrated time-dependent demands. Three models are developed: The first model uses continuously compounded demands, the second model uses linear demands integrated with continuously compounded demands, and the third model uses quadratic demands integrated with continuously compounded demands. Mathematical models are delineated for each model and relevant examples are provided to elucidate the proposed procedure. The objective herein is to obtain optimum order quantities and order intervals concerning the overall cost. Sensitivity analysis is provided for each of the three models. The necessary data was generated using Visual Basic 6.0.

Analisis Pengendalian Persediaan Obat Bpjs Dengan Metode Analisis ABC, Metode Economic Order Quantity (EOQ), Dan Reorder Point (ROP)

Hermina Ciputal Hospital is include the hospital that implement the BPJS program. From March 2014 to Desember 2019 there has been a marked increase in the number of patients. This increase was followed by the increasing need for BPJS medicines. The use of Indonesia-Case Based Group (INA-CBGs) tariffs requires efficient and affective services, including in the procurement of BPJS drugs. This type of research is operational research that aims to determine the value of drug use and investment, the optimum order amount and the time of reorder. The data used in this study are primary data optained from interviews and observations and secondary data obtained through the study of documents related to research. The subjects of the study were the Head of Pharmacy installation and Person in Charge of Pharmaceutical Supplies Management at Ciputat Hermina Hospital. BPJS drug inventory control at the PharmacyInstallation at Hermina Ciputat Hospital is done through stock taking, stock cards, defect books and monthly reports. But not yet using special control methods, both for priority types of supplies, the number of orders and when ordering drugs. From the results of the study through ABC analysis there are 17 types of drugs that are classified as group A that need to be prioritized in inventory control. Based on the Economic Order Quantity (EOQ) method, the optimum order quantity for these 17 drugs varies from 62-54 items. Based on the Reorder Point (ROP) method, it is obtained that the reorder time varies from 66-5555 items. Based on the results of the study, it is suggested to the Pharmacy Installation of Hermina Ciputat Hospital to apply the Economic Order Quantity (EOQ) and Reorder Point (ROP) method to BPJS group A drugs to avoid stock out and purchasing cito.Keywords: BPJSABC analysisEconomic Order QuantityReorder PointABSTRAK Rumah Sakit Hermina Ciputat adalah salah satu rumah sakit yang menerapkan program BPJS. Sejak Maret 2014 sampai Desember 2019 telah terjadi kenaikan jumlah pasien secara signifikan. Kenaikan ini diikuti dengan kenaikan kebutuhan obat-obatan BPJS. Penggunaan tarif Indonesian- Case Based Group (INA-CBGs) menuntut pelayanan yang efisien dan efektif, termasuk dalam pengadaan obat BPJS. Jenis penelitian ini adalah operasional research yang bertujuan untuk mengetahui nilai pemakaian dan investasi obat, jumlah pemesanan optimum dan waktu pemesanan kembali. Data yang digunakan dalam penelitian ini adalah data primer yang di peroleh dari wawancara dan observasi serta data sekunder yang diperoleh melelui telaah dokumen terkait penelitian. Subjek dari penelitian ini Kepala Instalasi Farmasi dan Penanggung Jawab Pengelolaan Perbekalan Farmasi di RS Hermina Ciputat. Pengendalian persediaan obat BPJS di Instalasi Farmasi RS Hermina Ciputat dilakukan melalui stock opname, kartu stok, buku defekta dan laporan bulanan. Namun belum menggunakan metode pengendalian khusus, baik untuk prioritas jenis persediaan, jumlah pemesanan maupun waktu pemesanan obat. Dari hasil penelitian melalui analisis ABC, terdapat 17 jenis obat yang tergolong kelompok A yang perlu di prioritaskan dalam pengendalian persediaan. Berdasarkan metode Economic Order Quantity (EOQ) jumlah pemesanan optimum untuk 17 obat tersebut bervariasi mulai dari 62 – 546 item. Berdasarkan metode Reorder Point (ROP) diperoleh waktu pemesanan kembali yang bervariasi mulai dari 66 – 5555 item. Berdasarkan hasil penelitian disarankan kepada Instalasi Farmasi RS Hermina Ciputat sebaiknya melakukan penerapan metode Economic Order Quantity (EOQ) dan Reorder Point (ROP) pada obat BPJS kelompok A untuk menghindari stock out dan pembelian cito.Kata Kunci: BPJSAnalisis ABCEconomic Order Quantity (EOQ) Reorder Point (ROP)

Questions on Technological Optimization of Centralized Flaring of Associated Hydrocarbon Gas from Sources with Different Methane Concentration

The method of technological optimization of associated hydrocarbon gas centralized flaring from sources with different methane concentration is suggested. The technological scheme of centralized flaring is composed. The relevant optimization task is formulated and solved solution of which make it possible to obtain the optimum type interrelation between methane concentration in associated gas and wind speed. As a result of carried out optimization the optimum order for functioning of composed technological scheme of centralized flaring of associated gas is recommended.

Uncertain Autoregressive Model via LASSO Procedure

Uncertain time series analysis is a method to predict future values based on imprecisely observed values. As a basic model of uncertain time series, an uncertain autoregressive model has been presented. However, the existing paper ignores the temporal dependence information embedded in time-series data. In dealing with this issue, this paper adds a least absolute shrinkage and selection operator penalty to the traditional uncertain autoregressive model and selects the optimum order of the model according to Akaike’s final prediction error criterion. Finally, two numerical examples are given to illustrate the effectiveness of the model and compare the results predicted by the uncertain autoregressive model with the principle of least squares.

A Procedure for Scheduling Inventory of an Industry by Merging Forecasting and Linear Programming

In this paper, we develop a mathematical model combining forecasting and linear programming for a business organization of Bangladesh to calculate optimum order quantity and inventory cost. We test the model using raw data of the demand for the raw materials and spare inventory for the industry and find out minimum total inventory cost along with ordering cost and inventory holding cost. The developed model make a match between the forecasted demand of raw materials and spare inventory and the minimum total cost of inventory. Finally comparing minimum cost, we observe that our estimated appropriate forecasting method gives optimal inventory cost. Dhaka Univ. J. Sci. 68(1): 65-70, 2020 (January)

Inventory Model for Three–parameter Weibull Deterioration and Partial Backlogging

This paper develops an economic order quantity inventory model for time dependent three parameters Weibull deterioration. Partially backlogged shortages are considered. The demand rate is deterministic and time dependent. The rate of deterioration is time dependent. We have derived the most favorable order quantity model by minimizing the entire inventory cost. A numerical illustration has been carried out to evaluate the result of parameters on decision variables and the total average cost of the model. The research focus of this paper is to derive the optimum order quantity by minimizing the total inventory cost.