Journal Jurnal Optimasi Sistem Industri-
Jurnal Optimasi Sistem Industri, Volume 17, pp 101-112; doi:10.25077/josi.v17.n1.p101-112.2018
Abstract:The success of a project is uncertain. There is a possibility that the project was successful or failed. Some of the risks that may occur in the project include the arrival of goods or the completion of work late from the time set, design changes due to obstacles in the field, as well as other risks. It is therefore necessary to study the project risks to identify potential problems that may occur and make decisions to reduce risks and increase the likelihood of success of the project. In order for risk management to be performed, the owner must know the steps in evaluating the project and the steps in the implementation of risk management. This study discusses the development of algorithms for project evaluation and risk management. The resulting algorithm is then implemented to the CC-II civil construction project at Indarung VI Project. The results of the implementation show that the project is not running in accordance with the plan. The dominant factors causing delays include BOQ miscalculation by consultants, inadequate and slow decision-making mechanisms, and details of workmanship changes.
Jurnal Optimasi Sistem Industri, Volume 17, pp 46-54; doi:10.25077/josi.v17.n1.p46-54.2018
Abstract:In a manufacturing process, quality is not only seen from the final product, but also manufacturing process. PT JI located in Cikarang is a company that produces paints and powder coating. Currently, the company has problems with 24.16% products that need rework or additional process. To increase productivity, PT JI applies the A3 project that is Right First Time (RFT). RFT is how to create a product with a one-time process and produce a product that has good quality on the first test. The average percentage of total RFT products in September 2016-January 2017 was 75.84%. This result is still below the company target of 80%. This study found the source of problems analyzed the manufacturing process using control chart, process capability, fishbone, and pareto. Taguchi method and ANOVA are applied to improve the design process. The application of the Taguchi Method shows that the factors which influence the value of viscosity quality are number of White Spirit, Number of Genekyd, Total Tio2 (kaolin), and mixing temperature, where each factor has an optimal level of 26.01%, 56.07%, 18.78% and 45oC. Then, it is found that all control factors have significant effect on viscosity value from ANOVA analysis. The application of this Taguchi method increases the process capability to Cp = 1.68 and Cpk = 1.43 from Cp = 0.29 and Cpk = 0.18, as well as an increase in RFT percentage of 5.78% or to 81.62% over the last two months.
Jurnal Optimasi Sistem Industri, Volume 17, pp 16-25; doi:10.25077/josi.v17.n1.p16-25.2018
Abstract:E-commerce is a breakthrough in doing business in a digital platform that offers many advantages over conventional business transactions. Indonesia as a country with the sixth largest internet users trying to use the internet as a new way of doing business. The Indonesian government also seriously supports e-commerce with the issuance of Presidential Regulation no. 74 of 2017 in August 2017 on the electronic map of electronic commerce (Road Map E-Commerce) of the Year 2017-2019. With great support from the Government, e-commerce can improve business transactions in Indonesia including for small and medium businesses in Bangka Belitung. Currently, UMKM business development is quite good but not many who take advantage of e-commerce as a way to improve and expand the business. This study aims to analyze the factors that encourage or hamper business actors in Bangka Belitung SME utilizing e-commerce. This research uses Analytical Hierarchy Process (AHP) methodology to construct hierarchically those factors. This research produces several factors that become the main concern of business in utilizing e-commerce, that is technology constraint with weight 33,2%, with sub most influential criteria is information technology mastery factor with weight equal to 38,6%. While the type of business is the most widely ditekuni is a typical food production business that reaches the weight of 38.8%.
Jurnal Optimasi Sistem Industri, Volume 17, pp 1-15; doi:10.25077/josi.v17.n1.p1-15.2018
Abstract:PT. Semen Padang is one of the cement producers competing to meet the needs of the cement. To that end, PT. Semen Padang must ensure the availability of cement on time, quantity, location and at competitive rates. One way to achieve this by optimizing the distribution system because it will be able to maximize sales and increase corporate profits. In this research, the distribution network planning model of PT. Semen Padang considering the cost of transportation, facility capacity, time, and uncertain demand. This model aims to minimize the total cost of product distribution and cost of opening the buffer warehouse and Packing Plant and maximize responsiveness to customers considering the uncertain parameters by using Fuzzy Multi-Objective Programming method. Based on the results of the research, had obtained the product distribution network planning model by using the fuzzy multi-objective programming method with the output is the opening of Packing Plant and buffer warehouse and the amount of product delivery to the final consumer with minimum cost and time of distribution. Search solution or output model assisted with Software Lingo 17.0. The designed model is able to explain the change of output if there are any changes in parameters covering demand between marketing areas, transportation costs between marketing areas and vehicle speed in transporting products from the last distribution center to the marketing area. The model can be implemented in the distribution network planning of PT. Semen Padang by using data in accordance with the conditions in the field.
Jurnal Optimasi Sistem Industri, Volume 17, pp 86-100; doi:10.25077/josi.v17.n1.p86-100.2018
Abstract:UKM Simo was established in 2002 and produces various hygiene products such as detergent soap, bath soap, softener and others. Currently, Simo has a mainstay product in the form of bath soap for the hotel. However, these products still cannot dominate the Batam market. Sales of bath soap are declining. The decline is due to soap products that are made not in accordance with customer expectations. This study looks for product specifications that meet customer expectations. The method used is quality function deployment (QFD). The purpose of this study is to design a quality soap product in accordance with customer expectations. The customer voices are grouped in such a way as to get an overview of customer expectations. The process of grouping is done by using exploratory factor analysis method. Through exploratory factor analysis, the company can get customer expectations that may not be explored through the questionnaire. Through this general overview, customer expectations are detailed up to the tertiary stage. The priority of customer expectations is determined based on the questionnaire data so that the allocation of resources can be done appropriately. Details of these expectations are related to the technical characteristics. Through the technical characteristics, the company is able to make products according to the customer expectations.
Jurnal Optimasi Sistem Industri, Volume 17, pp 75-85; doi:10.25077/josi.v17.n1.p75-85.2018
Abstract:The process of batik tulis (hand-waxed batik) dying in Kalinyamat Wetan, Tegal Municipality is performed in stooping and squatting working postures. Workers’ both hands hold a cloth and dip the cloth into a bucket containing colorants. When this dip dyeing process proceeds continuously for an enormous number of cloths, it will eventually result in musculoskeletal complaint, particularly in the such parts of body as the back, neck, leg, upper arm, lower arm and wrist. This research aims at designing an ergonomic batik dying machine to enable a natural body posture at work. The research anthropometry data and Rapid Entire Body Assessment (REBA) method. The research on batik craftswomen’s working posture during the traditional dip dyeing process found that the stooping and squatting worker’s posture scores are 4-8 with medium to high musculoskeletal levels (needs to needs to be immediately corrected). Meanwhile, the machine dip dyeing work position with standing body posture scores are 2-4 with safe to low musculoskeletal level (maybe need to be corrected in longer term). As for the specification of batik dyeing machine, it uses driving force of 0.190 HP, machine rotation of 72.5 rpm.
Jurnal Optimasi Sistem Industri, Volume 17, pp 55-63; doi:10.25077/josi.v17.n1.p55-63.2018
Abstract:Leaders who have transformational, empowerment, and other positive characteristics positively affect the performance of employee creativity. This study aimed to confirm and clarify the influence of leadership on employee creativity through meta-analysis method. Thirty-two titles of articles with 33 studies used in the analysis, yielding correlation values that support the hypothesis (0.27). In a geographical perspective, there is no difference between the west and the east. This can be seen from the comparable correlation value of each 0.268 and 0.274. However, in a sectoral perspective, manufacturing firms have a more prominent correlation (0.322) than service firms or mixed (0.238 and 0.235). Different motivation factors need to be considered as the link between personal and contextual factors. Therefore, further research should be done to examine the role of different motivations in linking the leadership support on employee creativity.
Jurnal Optimasi Sistem Industri, Volume 17, pp 64-74; doi:10.25077/josi.v17.n1.p64-74.2018
Abstract:The scheduling of electrical energy usage during Peak Load Period (PLP) is a complicated problem that has been faced by PT Semen Padang after Indonesian Power Company (PLN) implemented the demarcation regulation of electrical energy usage during PLP (6:00 – 10:00 p.m.) which may not exceed 44.100 kWH. This regulation forces Production Department of PT Semen Padang to arrange the “on (1) or off (0)” schedule for the Raw Mills and Cement Mills during PLP. A Raw Mill or Cement Mill can be switched-off if the specified criteria are satisfied. Those criteria refer to the achievement of daily production targets, silo content at PLP, and the requirement for particular Raw Mill or Cement Mill to be off during those 4 hours of PLP. Meanwhile, the constraints are related to the length of machining hours of Raw Mill, Kiln or Cement Mill before preventive maintenance takes place. To solve this problem, a scheduling model for Raw Mills and Cement Mills on-off during PLP is then developed using a linear programming approach. The decision variables are the “on-off” state of Raw Mills and Cement Mills during PLP, while the objective function is to minimize the penalty expense of energy used during PLP. The developed scheduling model has the ability to solve the problem of the “on-off” assignment for Raw Mills and Cement Mills from Indarung II to Indarung V. This scheduling model can decrease the penalty of electrical energy expense during PLP from Rp. 3.07 billion to Rp. 1.79 billion.
Jurnal Optimasi Sistem Industri, Volume 17, pp 35-45; doi:10.25077/josi.v17.n1.p35-45.2018
Abstract:Distribution process at PT XYZ is identical to one of the variants of Vehicle Routing Problem (VRP) which there are several vehicles with different capacities and operation cost, called as Heterogeneous Fleet Vehicle Routing Problem (HFVRP). There are two kinds of vehicle that have been used, namely, vehicle As and vehicle Bs. Vehicle As has the higher operation cost than vehicle Bs. Currently, the company implements policies where vehicle Bs is used if all vehicle As have been used. This policy may lead the distribution cost is so expensive and its equal with the operation cost of vehicle As that also high. Routing aims to combine the use of available vehicles to generate minimal distribution costs in servicing the customers. This research uses mathematical model according to the description of the distribution system in the company. The model is verified and tested using the optimization software. Then the constraints of the verifiable mathematical model are used as the basis for developing Insertion Heuristic (IH) algorithm. Comparison of model solutions with developed algorithm solutions showed a difference of 11.6%. This implies that the algorithm generated solution is quite good as one of the heuristic approaches that result in optimal local solutions. Implementation of IH algorithm provides cost savings of 5.97% towards the actual distribution system in the company.
Jurnal Optimasi Sistem Industri, Volume 17, pp 26-34; doi:10.25077/josi.v17.n1.p26-34.2018
Abstract:This paper presents a case study of determining vehicles’ routes. The case is taken from a pharmaceutical products distribution problem faced by a distribution company located in the city of Padang, Indonesia. The objective of this paper is to reduce the total distribution time required by the salesmen of the company. Since the company uses more than one salesman, then the problem is modeled as a multi traveling salesman problem (m-TSP). The problem is solved by employing genetic algorithm (GA) and a Matlab® based computer program is developed to run the algorithm. It is found that, by employing two salesmen only, the routes produced by GA results in a 30% savings in total distribution time compared to the current routes used by the company (currently the company employs three salesmen). This paper determines distances based on the latitude and longitude of the locations visited by the salesmen. Therefore, the distances calculated in this paper are approximations. It is suggested that actual distances are used for future research.