Physical inventories constitute a significant proportion of companies' investments in today's competitive environment. The trade-off between customer service levels and inventory reserves is addressed in practice by statistical inventory software solutions; given the tremendous number of Stock Keeping Units (SKUs) that contemporary organizations deal with, such solutions are fully automated. However, empirical evidence suggests that managers habitually judgementally adjust the output of such solutions, such as replenishment orders or reorder levels. This research is concerned with the value being added, or not, when statistically derived inventory related decisions (Order-Up-To, OUT, levels in particular) are judgementally adjusted. We aim at developing our current understanding on the effects of incorporating human judgement into inventory decisions; to our knowledge such effects do not appear to have been studied empirically before and this is the first endeavour to do so. A number of research questions are examined and a simulation experiment is performed, using an extended database of approximately 1,800 SKUs from the electronics industry, in order to evaluate human judgement effects. The linkage between adjustments and their justification is also evaluated; given the apparent lack of comprehensive empirical evidence in this area, including the field of demand forecasting, this is a contribution in its own right. Insights are offered to academics, to facilitate further research in this area, practitioners, to enable more constructive intervention into statistical inventory solutions, and software developers, to consider the interface with human decision makers.

No abstract

Bullwhip effect is a crucial problem in a supply chain. Bullwhip effect is distortion information between inventory and demand in the whole supply chain stages. This problem has not solved in the business recently, although there are many studies discussed this issue. Bullwhip effect gives a negative impact on the performance of the inventory system. This impact can reduce using Centralized Demand Information (CDI). This research aims to analyze the bullwhip effect that happens in between a manufacturer, distribution, and retailers to minimize inventory cost. This research aim is achieved by: i) Calculating the amount of bullwhip effect of PT. X that occurs in the bottled drinking water distribution system; ii) Implement the centralized demand information method to reduce the bullwhip effect on the supply chain water supply network; iii) Comparing inventory costs before and after cutting the bullwhip effect on the supply chain. The data such as time series, data in 12 periods (monthly), data on raw material procurement, holding cost and stockout costs. The reason for using CDI for calculating the bullwhip effect and Economic Order Quantity (EOQ) to calculate the inventory cost. Research findings show that using CDI will decrease the bullwhip effect and the impact is reducing inventory cost.

This research raises the problem of controlling the inventory of medicinal products. The case study was conducted at a drug store in the city of Solok, West Sumatra, where the drug store still has stock out and over stock of various types of drugs it manages. The purpose of this study was to control drug supplies that have a high demand value. Demand data for the period February-April 2020 are grouped with demand value criteria using the Pareto Classification ABC Method. From the demand categorization process, 45 types of drugs were included in A group, which means that this drug group provides a large revenue contribution for the drugstore. Thus, the type A drug group needs more attention from drug store manager in terms of controlling drug supplies. Furthermore, forecasting is carried out for drugs belonging to A drugs group using the Moving Average Method, the Single Exponential Smoothing Method and the Linear Regression Method. The inventory control method adopted is the Economic Order Quantity (EOQ) method. The results showed that the lot size of each type of drug per order ranged from 10-122 units with a safety stock ranging from 5-50 units of product. Then the reorder points obtained ranged from 8-81 units. With the control of drug supplies in place, it is hoped that the stock out and over stock that occurs in drug stores can be minimized.

Stock control is the most important aspect in an inventory system. It determines the safety stock in order to ensure that products are readily available when the customers require them. The decision makers in organizations tend to rely on software solution in obtaining stock control solutions since they have to manage a massive number of Stock Keeping Units (SKUs). However, managers intervene in the system and use their judgement to adjust or decide on various quantitative elements. This research discusses the effects of combination of stock control methods. An extended database of approximately 1,800 SKUs from an electronics company is analyzed. Then, a simulation experiment is performed in order to evaluate in a dynamic fashion what are the effects of applying combined stock control methods. The findings indicate that the combined method of stock control seems to improve the performance of the inventory system, especially in reducing inventory investment.

Pandemi Covid-19 yang terjadi pada saat ini telah menjadi bencana non alam global yang hingga per tanggal 27 Januari 2021 telah menginfeksi lebih dari 101 juta orang dan lebih dari 2,1 juta orang dinyatakan meninggal akibat terpapar virus Corona. Pandemi ini menjadi permasalahan besar yang melingkupi hampir seluruh negara di dunia. Walaupun pada saat ini telah ditemukan vaksin yang dapat digunakan untuk membangun kekebalan tubuh manusia terhadap virus ini, namun menjalankan kebiasaan hidup baru (new normal) dan patuh dalam melaksanakan protokol kesehatan (mencuci tangan dengan sabun-memakai masker-menjaga jarak fisik dan menghindari kerumunan) masih menjadi cara paling jitu dalam meutus rantai penyebaran Covid-19. Untuk dapat menjalankan protokol kesehatan ini, penggunaan APD menjadi hal yang sangat penting bagi masyarakat umum. Namun, kekurangan dan keterbatasan APD menjadi permasalahan baru di berbagai daerah. Kekurangan APD di berbagai daerah, termasuk di Kota Padang Provinsi Sumatera Barat ditandai dengan ketidaktersdiaan APD di berbagai toko obat dan apotek serta swalayan. Kondisi ini menyebabkan kekhawatiran masyarakat terhadap pemenuhan kebutuhan APD dan menjadi pemicu terjadinya panic buying. Ketidakpastian kebutuhan APD menjadi penyebab sulitnya pengambil keputusan dalam menentukan mengelola pengadaan APD tersebut. Sehingga perlu dilakukan suatu kajian yang memprediksi kebutuhan APD di masa pandemi Covid-19. Penelitian ini bertujuan untuk menghasilkan forecasting kebutuhan APD di masa pandemi covid-19 dengan menggunakan Metode Text Mining di Provinsi Sumatera Barat. APD yang diambil sebagai objek penelitian adalah APD berupa masker, pelindung wajah (face-shield), sarung tangan, sepatu boot karet dan baju hazmat. Dengan menggunakan data dari media sosial Twitter, dianalisis kebutuhan APD di Provinsi Sumatera Barat.

Proper layout arrangements can have an impact on minimizing the distance and time of the production process. The research was conducted at UKM X which produces fish-based snacks in Jambi Province where there is a back and forth flow in work activities due to the placement of work stations that are not in the order of the process flow and the placement of each process in a different room resulting in an increase in both working time and distance required in the production process. The purpose of this research is to re-design the layout of production process facilities in minimizing the distance between production processes by applying the Systematic Layout Planning (SLP) method. The results of this study indicate that the percentage of reduced material movement distance in the initial layout with the proposed alternative layout I is 21.56% (the selected proposed layout) and in the proposed II alternative layout is 15.94%. And the results of this study can be used as a guideline for UKM X managers which are used as case studies in research..

In a bakery, an operator needs a working tool for bread production process. To avoid injury and inconvenience the tool should be suitable and appropriate for the operator’s body posture and workload. Operators’ assistive device produced is trolley rack. Value engineering approach is carried out on this tool to identify and develop its functions in achieving the balance among cost, reliability and appearance of the product. The work-plan is divided into several development stages: creative stage, analysis stage, development stage and recommendation stage. Product value is determined by comparing between product benefits and product costs. This study employs Function Analysis System Technique (FAST) method which consists of 5 stages, namely information, creative, analysis, development and presentation/recommendation stages. The recommendation stage explains the best alternative design. The results show that alternative II has the highest performance value which is 97.16 and the highest rating of 0.45. It is rated as the best design and has good product durability.