Jurnal Teknik Industri

A Hybrid Scatter Search Heuristic Algorithm for Solving Cockpit Crew Rostering

Ahmad Rusdiansyah, Danim Musthofa, Nurhadi Siswanto, Maulin Masyito Putri — Mon, 28 Jan 2019 09:44:01 +0000

This research introduces the development of Hybrid Scatter Search Heuristic for solving cockpit crew (pilot and co-pilot) rostering problem. This research aims to minimize the deviation of flight hours among the cockpit crew of an airline, Garuda Indonesia Airline, during the one-month planning horizon. The weakness of the existing algorithm used in the airline, which is a trial-and-error algorithm, is that the variation among crew flight times for one month is too significant and the scheduling process takes a quite long time. We tested the performance of our proposed algorithm to that of the existing algorithm. The numerical experiments showed that the proposed algorithm had outperformed the existing algorithm. More specifically, we found some in sensitivity analysis experiments. Our experiment results showed that that the higher the flight time target, the higher the total deviation of flight time. We also conducted several experiments to show the robustness of our proposed algorithm. First, we tested the relationship between the number of pilots who can use their preferences and the total deviation of flight time. We conducted experiments by giving the cockpit crew the opportunity to choose a day off. Finally, we analyzed the results by changing the number of cockpit crew.

Investigation of Lockout / Tagout Procedure Failure in Machine Maintenance Process

Luciana Triani Dewi — Sat, 12 Jan 2019 13:57:58 +0000

Lockout/tag out (LOTO) refers to specific practices and procedures to stop the release of hazardous energy and turnoff machinery and equipment during service or maintenance activities. An effective LOTO system will ensure the workers are protected from the unexpected conditions during maintenance activities. This paper focus on incidents of LOTO system failures in an electricity power industry. LOTO system had implemented for many years in the company, but many incidents of LOTO system failure was still happened. The purpose of the research was to investigate the cases of incident caused by LOTO procedure failures. The research was conducted using descriptive analytical approach to analyse the cases of incident to find the root causes and develop the solution. Main data used in the research was document of incidents and was analysed by Systematic Cause Analysis Technique (SCAT). The result of investigation showed the root causes of LOTO system failure were caused by individual, job and management factors. Based on SCAT chart synthesis, the control actions were identified. The identified control movement were improve operational procedure of LOTO and proposed job description of supervisor. Evaluation of control action concluded that basically the suggestions were feasible to implement and some adjustments were needed due to implementation.

Managing Work Family Conflict and Work Stress through Job Satisfaction and Its Impact on Employee Performance

Riana Gede I — Sat, 12 Jan 2019 13:57:58 +0000

Work satisfaction has an important role in reducing work stress and work family conflict. This research aims to analyze the influence of work family conflict and work stress on the work satisfaction and performance of employees. Â The sample in this research is 46 married female employees. The data analysis technique used is the Partial Least Square (PLS) by using WarpPLS. The research results show that; work family conflict has a significant and negative influence on job satisfaction. Work family conflict has a significant and negative influence on employee performance. Work stress has a negative and significant influence on job satisfaction. Work stress has a negative and insignificant influence on employee performance. The analysis results provide information that work family conflict and work stress has an indirect influence on employee performance through job satisfaction. Furthermore, the indirect influence of work-family conflict on employee performance through job satisfaction is a full mediation. This means that job satisfaction has a strategic role in reducing the work stress and work family conflict so that it does not have a significant impact on employee performance. Job satisfaction can be improved by providing the feelings of fairness so that women can be satisfied with their job, conducting promotions, and supervisions. Finally, the social support of co-workers and management in the form of implementing family friendly policies is greatly needed to maintain the job satisfaction.

Scheduling Flexible Manufacturing System with Stacker Crane Using Coloured Petri Nets

Ari Setiawan, Teguh Ersada Natail Sitepu — Sat, 12 Jan 2019 13:57:57 +0000

Scheduling Flexible Manufacturing System (FMS) can increase production speed and accuracy. It because FMS has an ability to process various variety of product at same work station. However, FMS need efficient allocation of resources, for example: allocation of material handling equipment. This paper presents production scheduling FMS modelling to 24 jobs and 4 machines considering stacker crane. Coloured Petri Nets (CP-Nets) is the programming language which used to simulate model because itâ€™s simplicity. This model consists two main model activities. The first one is Physical Activity (PA) which related to every activity that involve physical movement, including stacker crane processes. PA consist five CP-Nets models: loading/unloading station, stacker crane, machine, picking mechanism, and pallet stocker. The second activity is Logical Expression (LE) which related to the rules on how FMS should operate. LE consist three CP-Nets models: machine selection, pick-up request, and stage two procedure.Â A simulation and numerical report show utilization level of all machines around 80-84% and stacker crane 8,74%.Â

The Effect of Top Management Involvement on Supply Chain Risk Management through Buyer-Supplier Relationship

Hotlan Siagian, Zeplin Jiwahusada Tarigan, Han Tae Hee — Sat, 12 Jan 2019 13:57:57 +0000

This paper aims to examine the role of the buyer-supplier relationship in improving the impact of top management involvement in the supply chain risk management. The study used 55 export-oriented manufacturing companies domiciled in East Java of Indonesia, and three respondents from top management level represented each company. Of 55, 44 companies have completed the questionnaires which means the response rate of 80%. Data collection used a questionnaire designed with a five-item Likert scale. Data analysis used the partial least square technique with Smart-PLS software version 3.0 to examine the hypotheses. The finding revealed that top management involvement affects supply chain risk management, top management involvement affects the buyer-supplier relationship, and buyer-supplier relationship affects supply chain risk management. The last finding is that buyer-supplier relationship empirically the effect of top management involvement. This paper paves the way for the manager in improving supply chain risk management by practicing top management involvement and development of a relationship with the supplier.

Robust Optimization Model for Bi-objective Emergency Medical Service Design Problem with Demand Uncertainty

Diah Chaerani, Siti Rabiatul Adawiyah, Eman Lesmana — Sat, 12 Jan 2019 13:57:56 +0000

Bi-objective Emergency Medical Service Design Problem is a problem to determining the location of the station Emergency Medical Service among all candidate station location, the determination of the number of emergency vehicles allocated to stations being built so as to serve medical demand. This problem is a multi-objective problem that has two objective functions that minimize cost and maximize service. In real case there is often uncertainty in the model such as the number of demand. To deal the uncertainty on the bi-objective emergency medical service problem is using Robust Optimization which gave optimal solution even in the worst case. Model Bi-objective Emergency Medical Service Design Problem is formulated using Mixed Integer Programming. In this research, Robust Optimization is formulated for Bi-objective Emergency Medical Service Design Problem through Robust Counterpart formulation by assuming uncertainty in demand is box uncertainty and ellipsoidal uncertainty set. We show that in the case of bi-objective optimization problem, the robust counterpart remains computationally tractable. The example is performed using Lexicographic Method and Branch and Bound Method to obtain optimal solution.Â

A Hybrid Greedy Algorithm and Simulated Annealing for Single Container Loading Problem: A Case Study

Gede A Widyadana, Audrey Tedja Widjaja, Kun Jen Wang — Sat, 12 Jan 2019 13:57:56 +0000

A single container loading problem is a problem to effectively load boxes in a three-dimensional container. There are many researchers in this problem try to find the best solution to solve the problem with feasible computation time and to develop some models to solve real case problem. Heuristics are the most method used to solve this problem since the problem is an NP-hard. In this paper, we introduce a hybrid greedy algorithm and simulate annealing algorithm to solve a real container loading problem in one flexible packaging company in Indonesia. Validation is used to show that the method can be applied practically. We use seven real cases to check the validity and performance of the model. The proposed method outperformed the solution developed by the company in all seven cases with feasible computational time.

Multi-items Batch Scheduling Model for a Batch Processor to Minimize Total Actual Flow Time of Parts through the Shop

Nita P.A Hidayat, Andi Cakravastia, T.M.A Ari Samadhi, Abdul Hakim Halim — Mon, 02 Jul 2018 08:06:34 +0000

This study is inspired by a batch scheduling problem in metal working industry which guarantees to satisfy a due date as a commitment to customers. Actual flowtime adopts the backward scheduling approach and considers the due date. Using the actual flowtime as the objective means that the solution Â is oriented to satisfy the due date, and simultaneosly to minimize the length of time of the parts spending in the shop. This research is to address a problem of scheduling batches consisting of multiple items of parts processed on a batch processor where the completed parts must be delivered several time at different due dates. We propose an algorithm to solve the problem.

The Impact of After-sales Service Quality on Customer Satisfaction and Customer Loyalty of Middle-upper Class Landed Housings

Didik Wahjudi, Timoticin Kwanda, Rianthi Sulis — Mon, 25 Jun 2018 15:52:55 +0000

Nowadays, good products are not sufficient. Market competition requires a good after-sales service. After-sales service quality has been identified as a source of revenue and competitive advantage. While other industry sectors have readily paid attention to after-sales service quality, little study has been done on the effectiveness of after-sales service quality in the field of real estate. This study aims to explore the relationship among after-sales service quality, customer satisfaction, and customer loyalty. Especially, we want to confirm the impact of after-sales service quality on customer satisfaction and customer loyalty of middle-upper class real estate in Surabaya. This research was conducted by survey on 170 respondents from four housing complexes in Surabaya, i.e. Pakuwon City, Citraland, Bukit Darmo Golf, and Graha Family. The data was examined by using structural equation modeling (SEM). Through data analysis we confirm the positive correlation between after-sales service quality and customer satisfaction, the positive correlation between customer satisfaction and customer loyalty, and the direct and indirect relationships between after-sales service quality and customer loyalty. The practical implication of this study provides assurance to real estate management on the effectiveness of after-sales service quality in maintaining old customers and encouraging new consumers.

Logistic Performance Measurement on a Port in Aceh

Prima Denny Sentia, Regita Ramadani, Sarika Zuhri — Sun, 17 Jun 2018 20:09:55 +0000

Indonesia government has established sea toll program through Presidential Regulation No.17 in 2017 to support inter-island distribution. Port X in Aceh is one of the ports included in sea toll program. This paper discusses logistic performance m.easure, especially in sea transportation. A Logistic Performance Index (LPI) is proposed as a tool to identify challenges and opportunities in Port X performance. Key indicators which affect the value of logistics performance index will also be studied in this paper. There are several logistic performance measurements for port X based on literature study: quality, delivery cost, transportation cost, and information. Eight indicators affect Port X performance: quality of the commodity, the quantity of the commodity, on time delivery, ship call, sea transportation cost, storage cost, electronic availability, and electronic access. Port X average total index, based on Analytical Hierarchy Process, is 2,557. This value can be considered as quite reasonable. The study limits logistic performance for the arrival route of the container vessel leading to Port X. The final result shows that quality performance indicator (quality quantity of commodity index) has the highest index for all originating port. The second highest index is electronic information availability index. Through this finding, Port X must improve their service and information because it plays a vital role in their performance

Uncapacitated Pricing Optimization for Mobile Broadband Services

Fransiscus Rian Pratikto — Sun, 17 Jun 2018 20:09:55 +0000

The success of revenue management starting in the mid-1980s has been driving pricing decision to be more tactical and operational. Since then, statistics and operations research have been important tools in pricing and revenue optimization. This research seeks to determine optimal price for mobile broadband services of a particular service provider. The case study is mobile broadband services in Indonesian market. We made a plausible assumption that there is no capacity constraint. We used choice-based conjoint with hierarchical Bayes estimation method to derive individual part-worth utilities, based on which market simulation was run to obtain the price-response function. By combining this with information about market size, we came up with a number of data points representing the demand function. Instead of fitting the data points with some theoretical demand functions, we used monotonic cubic splines to interpolate the demand function. Accordingly, we did not use explicit demand functions in the optimization, but a numerical interpolation function to estimate demand for any particular price level. Using enumeration, we then came up with a recommended contribution-maximizing prices under one, two, and three fare-classes segmentation. We assumed a perfect segmentation where cannibalization and arbitrage were not present. Further, we discussed a generalized optimal segmentation problem under that assumption. We also investigated the impact of the changes in competitorsâ€™ service attributes on the optimal prices.

Curriculum Assessment of Higher Educational Institution Using Trace-segmented Clustering

Satrio Adi Priyambada, Mahendrawathi ER, Bernardo Nugroho Yahya — Sun, 17 Jun 2018 20:09:55 +0000

Curriculum mining is research area that assess studentsâ€™ learning behavior and compare it with the curriculum guideline. Previous work developed sequence matching alignment approach to check the conformance between studentsâ€™ learning behavior and curriculum guideline. Considering only the sequence matching alignment is insufficient to understand the patterns of group of students. Another work proposed an approach by aggregating the studentsâ€™ profile to represent studentsâ€™ learning behavior and investigate the impact of the learning behavior to their learning performance. However, the aggregate profile approach considers the entire period of study rather than segmented period. This study proposes a methodology to assess studentsâ€™ learning path with segmented period i.e. the semester of the related curriculum. The segmented-period profile generated would be the input for sequence matching alignment approach to assess the conformity of studentsâ€™ behavior with the prior curriculum guideline. Real curriculum data has been used to test the effectivity of the methodology. The results show that the students can be grouped into various cluster per semesters that have different characteristic with respect to their learning behavior and performance. The results can be analyzed further to improve the curriculum guideline.

Optimal Retention for a Quota-Share Reinsurance

Lienda Noviyanti, Achmad Zanbar Soleh, Anna Chadidjah, Hasna Afifah Rusyda — Sun, 17 Jun 2018 20:09:54 +0000

The Indonesian Financial Services Authority (OJK) has instructed all insurance providers in Indonesia to apply a mandatory tariff for property insurance. The tariff has to be uniformly applied and the rule of set the maximum and minimum premium rates for protection against losses. Furthermore, the OJK issued the new rule regarding self-retention and domestic reinsurance. Insurance companies are obliged to have and implement self-retention for each risk in accordance with the self-retention limits. Fluctuations of total premium income and claims may lead the insurance company cannot fulfil the obligation to the insured, thus the company needs to conduct reinsurance. Reinsurance helps protect insurers against unforeseen or extraordinary losses by allowing them to spread their risks. Because reinsurer chargers premium to the insurance company, a properly calculated optimal retention would be nearly as high as the insurer financial ability.Â This paper is aimed at determining optimal retentions indicated by the risk measure Value at Risk (VaR), Expected Shortfall (ES) and Minimum Variance (MV). Here we use the expectation premium principle which minimizes individual risks based on their quota share reinsurance. Regarding to the data in an insurance property, we use a bivariate lognormal distribution to obtain VaR, ES and MV, and a bivariate exponential distribution to obtain MV. The bivariate distributions are required to derive the conditional probability of the amount of claim occurs given the benefit has occurred.

Ergonomic Checkpoint in Agriculture, Postural Analysis, and Prevalence of Work Musculoskeletal Symptoms among Indonesian Farmers: Road to Safety and Health in Agriculture

Ari Widyanti — Sun, 17 Jun 2018 20:09:54 +0000

Agriculture is one of the most crucial and hazardous sectors in both the developing and the developed countries. The agriculture area has a various problem related to safety and health, calling an urgent research to solve the problem. The purpose of this study is to apply ergonomics checkpoint in agriculture (developed by ILO) in Indonesian as well as to observe the prevalence of musculoskeletal symptoms among Indonesian farmers.

251 Indonesian farmers participate voluntarily in this study. â€œErgonomic checkpoint in agricultureâ€ as a tool to reduce agriculture-related accident and increase productivity is assessed by student researcher. Prevalence of musculoskeletal symptoms (MSS) is assessed using Nordic body map that is filling out by participants. Rapid Upper Limb Assessment (RULA), Rapid Entire Body Assessment (REBA), and postural analysis using 3 dimension Static Prediction Program (3D SSPP) are applied to observe the risk activities of Indonesian farmers including the manual hoe for land clearing, grass cutting for land clearing, planting the rice, manual plow, giving fertilizer, harvesting, threshing, cleaning the rice from the straw, and sun-drying of rice.Â

According to ergonomics checkpoints, material handling and storage are the worst in Indonesian agriculture, coupled with minimum safety information, toilet and washing facilities, and first aid. The high-risk activities are manual hoe for land clearing, manual plow, grass cutting for land clearing and threshing. The reported MSS mainly found in the shoulder and lower back.

In conclusion, Indonesian agriculture is in a poor ergonomics condition and is associated with high musculoskeletal symptoms. The postural analysis also reveals a high risk of farmer activities.

Measuring Supplier Service Quality in Indian SMEs Using Factor Analysis & GTA

Surjit Kumar Gandhi, Anish Sachdeva, Ajay Gupta — Sun, 17 Jun 2018 20:09:54 +0000

This study uses a hybrid scale to identify the factors contributing to the services delivered by the suppliers working with SME units in Indian setting. Application of EFA, CFA followed by GTA brings out a numerical measure of service quality index. 120 executives working at top/middle management levels in different SMEs of northern India responded to a questionnaire survey related to the assessment of services being delivered by their suppliers. The executives evaluated performance of their suppliers on the 1-5 Likert scale. Application of EFA followed by CFA revealed an interpretable latent structure comprising of five factors viz., Credibility, Relationship, Understanding, Alignment, and Dependability with 17 indicator items. Further, application of GTA resulted in an index value of Supplier Service Quality. This paper thus provides a framework for the measurement of SSQ in a previously less explored manufacturing sector. The proposed scale can be used as a benchmark by SME units for evaluation of supplier service quality. This methodology used may be applied in more such situations so that generalizations can be contemplated.

Perbandingan Algoritma Simulated Annealing dan Harmony Search dalam Penerapan Picking Order Sequence

Tanti Octavia, Septiananda Angelica — Tue, 09 Jan 2018 10:01:18 +0000

Implementation of mobile rack warehouse is commonly used in manufacturing industry because it can minimize the warehouse area used. Applying picking orders in taking of Stock Keeping Unit (SKU) on mobile rack warehouses could give fast loading order. This research aims to find out which algorithm is better in applying picking order sequence in mobile rack warehouse. The algorithm used is Simualted Annealing (SA) and Harmony Search (HS) algorithm. Both of these algorithms will be compared in terms of the gap with the shortest path method.The result shows that the HS algorithm produces a better solution than the SA algorithm with lower CPU time, but the convergence rate of HS is lower than that of SA.HS was able to produce a better solution than the shortest path method of 9 cases, while SA only 8 cases from 15 cases.

Algoritma Genetika untuk Pemecahan Masalah Rute Kendaraan dengan Ukuran dan Campuran Armada, Trip Majemuk, Pengiriman Terbagi, Produk Majemuk, dan Kendaraan dengan Kompartemen Majemuk

Suprayogi Suprayogi, Daniel Bunga Paillin — Mon, 08 Jan 2018 09:38:37 +0000

This paper discusses a variant of the basic vehicle routing problem (VRP) by including the following characteristics: fleet size and mix, multiple trips, split delivery, and multiple compartments. One of real cases of this problem is related to determining tankerâ€™s routes in delivering fuel products from a supply port to a number of destination ports. Each tanker has several compartments where each compartment is dedicated to a certain fuel product. In this paper, a solution approach based on genetic algorithm (GA) is proposed and tested using nine hypothetical instances. Experiment results show that the proposed GA gives consistent results measured by coefficient variations

Implementasi Metode Metaheuristik Symbiotic Organisms Search Dalam Penentuan Tata Letak Fasilitas Proyek Konstruksi Berdasarkan Jarak Tempuh Pekerja

Doddy Prayogo, Richard Antoni Gosno, Richard Evander, Sentosa Limanto — Mon, 08 Jan 2018 09:37:47 +0000

Penelitian ini menyelidiki performa dari metode metaheuristik baru bernama symbiotic organisms search (SOS) dalam menentukan tata letak fasilitas proyek konstruksi yang optimal berdasarkan jarak tempuh pekerja. Dua buah studi kasus tata letak fasilitas digunakan untuk menguji akurasi dan konsistensi dari SOS. Sebagai tambahan, tiga metode metaheuristik lainnya, yaitu particle swarm optimization, artificial bee colony, dan teachingâ€“learning-based optimization, digunakan sebagai pembanding terhadap algoritma SOS. Hasil simulasi mengindikasikan bahwa algoritma SOS lebih unggul serta memiliki karakteristik untuk menghasilkan titik konvergen lebih cepat jika dibandingkan dengan metode metaheuristik lainnya dalam proses optimasi tata letak fasilitas proyek konstruksi.

Pengoptimuman Portofolio dengan Kendala Karakteristik Perusahaan Emiten

Ezra Putranda Setiawan, Dedi Rosadi — Mon, 08 Jan 2018 09:36:57 +0000

Diversifikasi saham merupakan salah satu cara yang dilakukan investor untuk memperkecil risiko investasi. Pada umumnya, diversifikasi mengacu pada hasil perhitungan matematis berdasarkan nilai pengembalian (return) masing-masing saham, misalnya pada model mean-variance. Dalam penelitian ini dibahas modifikasi model mean-variance yakni dengan menambahkan kriteria yang berkaitan dengan perusahaan emiten, misalnya bidang usaha, status perusahaan, dan sebagainya. Sebagai contoh, investor dapat menentukan bahwa portofolio yang dibentuk hanya melibatkan sejumlah saham dari sektor pertambangan, sejumlah saham dari sektor perdagangan, dan sebagainya. Penyelesaian masalah pengoptimuman portofolio ini ditentukan dengan metode algoritma genetika. Studi kasus dilakukan pada sejumlah saham yang diperdagangkan di Bursa Efek Indonesia.

Exploring the causes of Low-Productivity in Dairy Supply Chain using AHP

Rahul S Mor, Sarbjit Singh, Arvind Bhardwaj — Mon, 08 Jan 2018 09:35:32 +0000

Dairy industry is one of the essential global industries with considerably important implications for world economy where the dairy supply chains (DSC) cover every stage of the food system starting from the milk production at farmer level to final consumption. For achieving success in the dairy supply chain, it is needed to focus on critical factors (CFs) that are necessary for an organization to achieve its corporate goals with continually improving the operational performance. In this context, the current study is an attempt to identify the critical factors causing low-productivity in dairy supply chains. After comprehensive literature review and pilot studies in some dairy industries located in northern region of India, a total of 32 critical factors have been identified. A structured questionnaire consisting of 32 CFs have been circulated and the data has been collected from select cooperative dairy units. Further, only eight major critical factors have been carried forward for AHP analysis based on the data collected. The factor having higher weightage score is considered as major CF. The findings of this study indicate that the poor logistics and transportation facilities is the most critical factor as productivity barrier in the context of coop. milk processing units in northern India. This research study would be useful for the dairy professionals & managers of milk processing units to manage their production operations effectively by considering the identified CFs.

Tabu Search for the Vehicle Routing Problem with Multiple Trips, Time Windows, and Simultaneous Delivery-Pickup

Suprayogi Suprayogi, Yusuf Priyandari — Mon, 08 Jan 2018 09:34:25 +0000

This paper discusses a vehicle routing problem with multiple trips, time windows, and simultaneous delivery-pickup (VRPMTTWSDP). This problem is a variant of the basic vehicle routing problem (VRP) including the following characteristics: multiple trips, time windows, and simultaneous delivery-pickup. Â In this paper, a solution approach based on tabu search (TS) is proposed. In the proposed TS, the sequential insertion (SI) algorithm is used to construct an initial solution. A neighbor structure is generated by applying an operator order consisting of eleven operators of relocation, exchange, and crossover operators. A tabu solution code (TSC) method is applied as a tabu restriction mechanism. Computational experiments are carried out to examine the performance of the proposed TS using hypothetical instances. The performance of the proposed TS is compared to the local search (LS) and the genetic algorithm (GA). The comparison shows that the proposed TS is better in terms of the objective function value.

Space-sharing Strategy for Building Dynamic Container Yard Storage Considering Uncertainty on Number of Incoming Containers

Siti Nurminarsih, Ahmad Rusdiansyah, Maulin Masyito Putri — Mon, 08 Jan 2018 00:00:00 +0000

The implementation of AEC (Asian Economic Community) leads to demand increase at ports in Indonesia. This increasing demand is followed by operational efficiency at the port as well. In fact, ports in Indonesia have an average dwell time for 5 days. One of the causes of this long dwell time is container transfer inefficiencies during loading process. In this research, we will focus in yard management and increasing land utilization. To increase the land utilization, we develop the space-sharing concept to reduce the initial space needed for a given workload. Since the ships arrivals are also varying, this concept will be possible. We develop the concept by adding uncertainty on number of incoming containers at operational level as the determining factor in planning a shared yard area. We propose a simulation approach to evaluate strategies in making yard template.

Model Optimisasi Robust untuk Mengatasi Ketidaktentuan Estimasi Durasi Operasi pada Masalah Penjadwalan Ruang Operasi Rumah Sakit

Diah Chaerani, Ija Royana, Elis Hertini — Thu, 01 Jun 2017 00:00:00 +0000

Masalah penjadwalan ruang operasi di rumah sakit merupakan masalah keragaman durasi operasi yang memerlukan penjadwalan untuk mengurangi tingkat kesibukan ruang operasi.Â Masalah yang harus diselesaikan dalam penjadwalan ruang operasi adalah bagaimana menempatkan pasien ke dalam blok ruang operasi yang tersedia secara optimal untuk meminimumkan waktu tunggu pasien. Masalah ini dapat disajikan dalam sebagai masalah optimisasi dalam formulasi mixed integer linear programming (MILP). Pada prakteknya sering terjadi ketidaktentuan estimasi durasi operasi yang dapat mengakibatkan jadwal operasi tidak berjalan sesuai perencanaan awal, sehingga pasien tidak dapat dioperasi sesuai dengan waktu yang telah ditentukan. Dalam makalah ini dikaji pemodelan masalah optimisasi tak tentu dengan menggunakan teknik pemodelan Optimisasi Robust (OR) dalam hal mengatasi ketidaktentuan estimasi durasi operasi pada masalah penjadwalan ruang operasi rumah sakit. Dalam metodologi OR diperkenalkan Robust Counterpart (RC), dimana Â tujuan utama yang ingin dicapai adalah menguji level robustness dengan cara menguji formulasi model robust counterpart yang dihasilkan apakah dapat direpresentasikan dalam jenis kelas masalah optimisasi yang dapat terjamin sebagai kelas masalah yang computationally tractable. Pemilihan jenis himpunan taktentu untuk merepresentasikan data taktentu yang terlibat dalam pemodelan sangat menentukan, untuk memastikan Â apakah formulasi robust counterpart yang diperoleh merupakan masalah yang computationally tractable atau tidak. Dapat disimpulkan bahwa model RC yang diperoleh termasuk dalam kelas masalah yang computatioonally tractability, dalam hal ini model tak tentu dapat direpresentasikan dalam formulasi model optimisasi dalam bentuk linear programming (untuk box uncertainty set) dan conic quadratic programming (untuk ellipsoidal uncertainty set).

Designing Indonesian Liner Shipping Network

Thu, 01 Jun 2017 00:00:00 +0000

As the largest archipelago nation in the world, Indonesiaâ€™s logistics system has not shown excellence according to the parameters of logistics performance index and based on logistics costs percentages from overall GDP. This is due to the imbalances of trading on the western and eastern regions in Indonesia, which impacts the transportation systems costs to and from the eastern regions. Therefore, it is imperative to improve the competitiveness of Indonesian maritime logistics through maritime logistics network design. This research will focus on three levels of decision making in logistics network design, which include type of ships in the strategic level, shipping routes in the tactical level, and container allocation in the operational level with implementing butterfly routes in Indonesiaâ€™s logistics networking problems. Furthermore, this research will analyze the impact of Pendulum Nusantara and Sea Toll routes against the company profits and percentages of containers shipped. This research will also foresee how demand uncertainties and multi-period planning should affect decision making in designing the Indonesian Liner Shipping Network.

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

Gan Shu San, I Nyoman Pujawan — Thu, 01 Jun 2017 00:00:00 +0000

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 consumerâ€™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 demandâ€™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 retailerâ€™s optimization. Furthermore, the remanufactured productâ€™s wholesale and retail prices are influenced by the expansion effectiveness coefficient.

Pengembangan Model Persediaan Continuous Review dengan All-Unit Discount dan Faktor Kadaluwarsa

Cherish Rikardo, Dharma Lesmono, Taufik Limansyah — Thu, 01 Jun 2017 00:00:00 +0000

Paper ini membahas suatu model matematika untuk suatu sistem persediaan dengan mempertimbangkan adanya all-unit discount dan faktor kadaluwarsa. Permintaan barang bersifat deterministik yang merupakan fungsi dari waktu dan bergantung pada jumlah persediaan yang ada (inventory dependent demand), laju kadaluwarsa barang juga bergantung pada waktu dan tidak ada lead time. Model yang dibahas merupakan pengembangan dari Nagare dan Dutta [9] dengan menambah faktor all-unit discount dan laju kadaluwarsa yang bergantung pada waktu. Dari model yang dikembangkan akan ditentukan kuantitas pemesanan (economic order quantity) dan waktu antar pemesanan yang optimum yang meminimumkan total biaya persediaan tahunan. Algoritma penentuan solusi optimum dari model yang dikembangkan dan contoh numerik sebagai ilustrasi dari permasalahan persediaan ini diberikan. Analisis sensitivitas model dengan melihat pengaruh laju kadaluwarsa dan laju permintaan terhadap kuantitas dan waktu antar pemesanan yang optimal juga diberikan. Dari hasil analisis sensitivitas diperoleh bahwa semakin besar laju kadaluwarsa, maka waktu antar pemesanan menjadi semakin singkat dan kuantitas pemesanan menjadi semakin sedikit.Â Hal yang sama terjadi jika laju permintaan barang semakin besar.

Kata kunci:Â Persediaan, kadaluwarsa, all-unit discount.

Kontrol Optimal pada Model Economic Order Quantity (EOQ) dengan Inisiatif Tim Penjualan

Abdul Latif Al Fauzi, Isnani Darti, Agus Suryanto — Thu, 01 Jun 2017 00:00:00 +0000

Pengendalian Â tingkat persediaan stok suatu produk/barang merupakan salah satu kegiatan yang penting dalam kelancaran penjualan, yang juga berakibat pada keuntungan yang akan diperoleh dari penjualan suatu produk/barang.Â Model Economic Order Quantity (EOQ) merupakan salah satu model persediaan barang yang sering digunakan untuk pengendalian persedian barang. Pada artikel ini dibahas kontrol optimal pada model EOQ dengan inisiatif tim penjualan tidak hanya pada saat kondisi setimbang saja, tetapi kontrol optimal dengan usaha tim penjualan pada setiap saat. Strategi kontrol optimal dilakukan dengan meminimumkan biaya persediaan, biaya pembelian, biaya penjualan dan biaya usaha tim penjualan. Masalah kontrol optimal diselesaikan menggunakan prinsip maksimum Pontryagin. Solusi optimal yang diperoleh disimulasikan secara numerik menggunakan metode Sweep Maju-Mundur. Berdasarkan hasil simulasi numerik dapat diketahui bahwa semakin besar koefisien tingkat permintaan barang, maka proses persediaan barang akan lebih cepat berkurang. Selain itu semakin besar usaha tim penjualan, maka proses persediaan barang akan lebih sedikit bahkan lebih cepat habis.

Model Optimasi Fixturing Benda-kerja dengan Prinsip 3-2-1 Klem Tunggal

Isa Setiasyah Toha, Mohammad Yazid Diratama, Dadan Heryada Wigenaputra — Thu, 01 Jun 2017 00:00:00 +0000

Untuk memegang benda-kerja pada tempatnya, diperlukan penetap (fixture). Beberapa penelitian sebelumnya membahas keseimbangan gaya dan momen yang berbasis pada model kinematik penetap, teori ulir (screw theory), melibatkan gaya kontak serta kesalahan posisi. Permasalahan yang paling mendasar dalam desain penetap adalah menentukan koordinat lokator dan klem serta gaya klem, agar benda-kerja stabil selama proses pemesinan. Makalah ini membahas model optimasi untuk menentukan koordinat lokator dan klem serta gaya klem, dengan memperhatikan keseimbangan gaya dan momen. Secara spesifik, model optimasi yang dikembangkan untuk permasalahan penetapan (fixturing) benda-kerja dengan prinsip 3-2-1 menggunakan klem tunggal. Untuk menunjukkan operasionalisasi model, digunakan contoh numerik penetapan benda-kerja nyata yang diselesaikan menggunakan perangkat-lunak Exel/Solver.

Model Integrasi Keputusan Lokasi, Perutean Kendaraan, dan Pengendalian Persediaan Pada Sistem Rantai Pasok Tiga Eselon

Nova Saragih, Senator Nur Bahagia, Suprayogi Suprayogi, Ibnu Syabri — Thu, 01 Jun 2017 00:00:00 +0000

Keputusan lokasi, perutean kendaraan, dan kebijakan persediaan merupakan keputusan yang saling terkait satu dengan yang lain. Keputusan pengendalian persediaan, seperti ukuran lot pemesanan dan frekuensi pemesanan akan mempengaruhi baik itu ongkos persediaan dan ongkos transportasi. Sebagai contoh, pengiriman dalam kuantitas yang sedikit dan frekuensi yang sering menyebabkan pengurangan ongkos persediaan tetapi membutuhkan tambahan ongkos transportasi. Selanjutnya, keputusan perutean dan keputusan pengendalian persediaan akan mempengaruhi keputusan pemilihan lokasi sebab pemilihan lokasi ditentukan berdasarkan kriteria ongkos sistem minimum. Kegagalan dalam melibatkan ongkos persediaan dan ongkos transportasi ke dalam pertimbangan ketika memilih lokasi dapat menyebabkan sub-optimalitas sebab keputusan pemilihan lokasi memiliki dampak yang besar pada ongkos persediaan dan ongkos transportasi. Oleh karena itu, bagaimana memilih lokasi, menentukan rute kendaraan, dan mengendalikan persediaan yang optimal menjadi isu yang penting dalam merancang sebuah sistem logistik. Penelitian ini mengembangkan model integrasi yang secara simultan mengoptimisasikan keputusan lokasi, rute kendaraan, dan pengendalian persediaan pada sistem rantai pasok tiga eselon yang belum pernah dikembangkan sebelumnya. Entitas yang terlibat dalam rantai pasok kajian terdiri dari satu Pemasok, multi Depot, dan multi Ritel. Karakteristik permintaan yang dipertimbangkan dalam penelitian ini bersifat probabilistik dan jumlah produk terdiri dari satu produk. Model integrasi yang dikembangkan selanjutnya dipecahkan dengan metode optimal dan metode heuristik. Setelah dilakukan perbandingan dengan model dekomposisi diperoleh kesimpulan bahwa model integrasi menghasilkan ongkos total sistem yang lebih kecil.

Penentuan Jadwal dan Rute Perjalanan Kapal dengan Batasan Waktu dan Jumlah Kunjungan

I Gede Agus Widyadana, Richard Wibisono — Thu, 01 Dec 2016 00:00:00 +0000

Scheduling and routing are important for a shipping company. In this paper a scheduling and routing model is developed to solve a shipping company problem. The model is different to some previous models since it considers the companyâ€™s constraints such as number of ports that can be visited in one route, number of calls in each port and minimum gap between consecutive visits. The model is applied in one shipping company in Surabaya, Indonesia and is solved using insertion heuristic and simulated annealing. The result shows that simulated annealing method can reduce 18.2% of total distance compare to previous companyâ€™s schedule and routes.

Reverse Logistics Systems: Persepsi dan Harapan Konsumen

Farida Pulansari, Dwi Sukma Donoriyanto, Nisa Masruroh — Thu, 01 Dec 2016 00:00:00 +0000

Complaint is a signal that indicates important information directly by customers. Complaint will give valuable information to company to plan recovery strategies to maintain customer satisfaction and loyalty. Hence, electronic waste (E-waste) becomes a hot issue internationally, domestically and locally. There are many kind of regulations, strategy, methods or approach to minimize of E-waste. The goal of this research is design of house of reverse logistics (HRL) to understanding the customer needs and wants for reverse logistics (RL) implementation. This research adopted quality function deployment (QFD) method to construct the HRL. Differences among them are determination of the customer needs and wants. HRL insert five perspectives i.e. input, structure, process, output, and social and organization. In other hand, QFD only inserts consumer perspectives. The results showed the important factors of consumer dissatisfaction comes from: third-party services mechanism (20%), collaboration RL system (collection centers, recycling centers, disposal center; 10%), the standardization of servicing system (10%).

Efek Keadilan Remunerasi, Kompetensi Atasan dan Kohesivitas Kelompok terhadap Withholding Effort

Ida Ayu Kartika Maharani, I Gede Riana, I Gede Adnyana Sudibya — Thu, 01 Dec 2016 00:00:00 +0000

Withholding effort is a tendency employee to reduce work contribution as the possibility of an individual in giving less than maximum effort on tasks associated with the job. The purpose of this study is to analyze the remuneration fairness influences, supervisor competencies and group cohesiveness on withholding effort. The population in this study was all administrative employees with the status of civil servants and probationary civil servants who were actively working in the Institute Hindu Dharma Negeri Denpasar. The number of respondents were 80 people. The research data was primary data obtained from questionnaires. This study used confirmatory factor analysis and multiple linear regression analysis as analytic technique. The results show that fairness of remuneration has a negative and significant effect on the withholding effort, supervisor competencies has a negative and significant effect on the withholding effort, group cohesivenessÂ has a negative and significant effect on the withholding effort.

Budaya Organisasi yang Mendukung Keselamatan Pasien di Rumah Sakit

Ari Widyanti — Thu, 01 Dec 2016 00:00:00 +0000

Organizational culture is one of important factors that contribute to the performance of an organization, including in a hospital. In a hospital, performance can be measured by its level of patient safety. Howover, studies and research that discuss the relationship of organizational culture and patient safety are still very limited, including in Indonesia. This research is conducted to observe organizational culture that support patient safety. This research is conducted in three hospitals in Jakarta. Type of organizational culture is identified using the Organizational Culture Assessment Instrument (OCAI) questionnaire and the level of patient safety is assessed using the Hospital Survey on Patient Safety Culture (HSOPSC) questionnaire. Once the organizational culture is identified and the level of patient safety culture is observed in each hospital, correlation test and analysis is conducted between types of organizational culture with aspect of patient safety based. Results show that three hospitals do not have dominant organizational culture. However, type of organizational culture that has a significant positive correlation with aspect of patient safety the most is adhocracy culture, eventhough other organizational culture type also support patient safety. The result of this research then used as initial suggestion to make change on organizational culture so that patient safety could be improved.

Peramalan Multivariate untuk Menentukan Harga Emas Global

David Christian, Siana Halim — Thu, 01 Dec 2016 00:00:00 +0000

Gold is one of the most enticing commodities and a very popular way of investing. Goldâ€™s price is allegedly influenced by another factors such as US Dollar, oilâ€™s price, inflation rate, and stock exchange so that its model is not only affected by its value. The aim of this research is to determine the best forecasting model and influencing factors to goldâ€™s price. This research is modeling gold using multivariate analysis and reviews the univariate modeling as a benchmark and comparison to the multivariate one. Univariate time series is modeled using the ARIMA model which indicates that the fluctuation of the gold prices are following the white noise. Goldâ€™s multivariate modeling is built using the Vector Error Correction Model with oilâ€™s price, US Dollar and Dow Jones indices, and inflation rate as its predictors. Researchâ€™s result shows that the VECM model has been able to model the goldâ€™s price well and all factors investigated are influencing goldâ€™s price. US Dollar and oilâ€™s price are negatively correlated with goldâ€™s price as the inflation rate is positively correlated. Dow Jones Index is positively correlated with goldâ€™s price only at its first two periods.

Genetic Algorithm for Solving Location Problem in a Supply Chain Network with Inbound and Outbound Product Flows

Suprayogi Suprayogi, Senator Nur Bahagia, Yudi Thaddeus — Thu, 01 Dec 2016 00:00:00 +0000

This paper considers a location problem in a supply chain network. The problem addressed in this paper is motivated by an initiative to develop an efficient supply chain network for supporting the agricultural activities. The supply chain network consists of regions, warehouses, distribution centers, plants, and markets. The products include a set of inbound products and a set of outbound products. In this paper, definitions of the inbound and outbound products are seen from the regionâ€™s point of view.Â The inbound product is the product demanded by regions and produced by plants which flows on a sequence of the following entities: plants, distribution centers, warehouses, and regions. The outbound product is the product demanded by markets and produced by regions and it flows on a sequence of the following entities: regions, warehouses, and markets. The problem deals with determining locations of the warehouses and the distribution centers to be opened and shipment quantities associated with all links on the network that minimizes the total cost. The problem can be considered as a strategic supply chain network problem. A solution approach based on genetic algorithm (GA) is proposed. The proposed GA is examined using hypothetical instances and its results are compared to the solution obtained by solving the mixed integer linear programming (MILP) model. The comparison shows that there is a small gap (0.23%, on average) between the proposed GA and MILP model in terms of the total cost. The proposed GA consistently provides solutions with least total cost. In terms of total cost, based on the experiment, it is demonstrated that coefficients of variation are closed to 0.

Model Penentuan Jumlah Kapal dan Komposisinya untuk Short Sea Shipping Pulau Jawa

Ika Deefi Anna, Fitri Agustina — Thu, 01 Dec 2016 00:00:00 +0000

This research aims to determine the amount and mixture composition of vessels in short sea shipping (SSS) operation in Java. SSS in Java is proposed to mitigate the surface transportation problem and move freight off the overcrowded North-Coast highways and rail systems onto the waterways. A mathematical model based on non-linear integer programming was developed to calculate the amount and the composition mix of vessels required for the proposed system. The model was solved by Lingo software and the computational results reveal that the proposed system would require daily shipment using 1 unit of type B vessel and 1 unit of type C vessel. The calculation results also show that the SSS in Java would require 6 vessels to operate. Overall, the model and the obtained solutions in this paper provide an alternative to raise awareness of short sea shippingâ€™s potential with the government, logistic companies, and executive policymakers. Finally, this paper also contribute to research of maritime fleet size and mix problems.

Defect Detection on Texture using Statistical Approach

Siana Halim — Fri, 07 Oct 2016 21:22:29 +0000

In this paper we present several techniques for detecting simple defect on the texture. The simple defect means, that the defect can be detected via image histogram or via wavelet of the image histogram. Hill estimator is one of the techniques that we suggest to use to solve this problem, since it does not need estimate parameters for estimating the image density

Solusi Optimal Model Optimisasi Robust Untuk Masalah Traveling Salesman Dengan Ketidaktentuan Kotak Dan Pendekatan Metode Branch And Bound

Poppy Amriyati, Diah Chaerani, Eman Lesmana — Fri, 07 Oct 2016 21:17:13 +0000

Traveling Salesman Problem (TSP) merupakan teknik pencarian rute yang dimulai dari satu titik awal, setiap kota harus dikunjungi sekali dan kemudian kembali ke tempat asal sehingga total jarak atau waktu perjalanan adalah minimum. Untuk mengatasi kedakpastian jarak atau waktu perjalanan, maka perlu dilakukan pengembangan model TSP. Salah satu bidang Optimisasi yang mampu menyelesaikan permasalahan terkait ketidakpastian adalah Optimisasi Robust. Dalam makalah ini dibahas mengenai penerapan Optimisasi Robust pada TSP (RTSP) menggunakan pendekatan Box Uncertainty dan diselesaikan dengan menggunakan Metode Branch and Bound. Disajikan simulasi numerik pada software aplikasi Maple untuk beberapa kasus nyata terkait penerapan Optimisasi RTSP , seperti masalah manajemen konstruksi, penentuan jarak tempuh kota di Pulau Jawa, dan Penentuan Rute Mandiri Fun Run.

Bayesian-based Project Monitoring: Framework Development and Model Testing

Budi Hartono, Riesa Ayuningtyas, Yun Prihantina Mulyani — Mon, 03 Oct 2016 15:58:31 +0000

During project implementation, risk becomes an integral part of project monitoring. Therefore. a tool that could dynamically include elements of risk in project progress monitoring is needed. This objective of this study is to develop a general framework that addresses such a concern. The developed framework consists of three interrelated major building blocks, namely: Risk Register (RR), Bayesian Network (BN), and Project Time Networks (PTN) for dynamic project monitoring. RR is used to list and to categorize identified project risks. PTN is utilized for modeling the relationship between project activities. BN is used to reflect the interdependence among risk factors and to bridge RR and PTN. A residential development project is chosen as a working example and the result shows that the proposed framework has been successfully applied. The specific model of the development project is also successfully developed and is used to monitor the project progress. It is shown in this study that the proposed BN-based model provides superior performance in terms of forecast accuracy compared to the extant models.

Pengembangan Metode Penstrukturan Masalah Berbasis Cognitive Map dan Strategic Choice Approach dan Penerapannya pada Masalah Manajemen Rantai Pasokan

Iwan Mumin Basarah, Sani Susanto — Thu, 29 Sep 2016 07:51:10 +0000

The problem structuring methods used to deal with complex Â and ill-structured problems. One of the method of structuring ill-structured Â problem is the Strategic Choice Approach (SCA), while one of the problems of complex and ill-structuredproblems Â is a supply chain management problems. This research proposes the use of a cognitive map as a base application of SCA on the problems of supply chain management at PT X, a leading manufacturing company in Indonesia. Three main results of this study are structuring problems, choosing of the top priority problems, and choosing of troubleshooting options among other identified options.

Karakteristik Kurva Efisien Frontier dalam Menentukan Portofolio Optimal

epha diana supandi — Thu, 29 Sep 2016 07:39:15 +0000

Pada tulisan ini karakteristik kurva efisien frontier pada model portofolio Markowitz diteliti secara matematis. Portofolio optimal diperoleh dengan menggunakan metode Lagrange. Pada penelitian ini juga dikaji karakteristik portofolio optimal pada portofolio minimum variance, portofolio tangency dan portofolio mean-variance serta posisinya pada kurva efisien frontier. Lebih lanjut untuk memberikan gambaran yang lebih konkrit maka diberikan contoh numerik pada beberapa saham yang diperdagangkan di pasar modal Indonesia.

Penilaian Keberlanjutan UKM Batik Kota Semarang dengan Metode Product Service System (PSS)

Ratna Purwaningsih, Novie Susanto, Mahardhika Cakra Yudha — Thu, 29 Sep 2016 07:07:48 +0000

UKM Batik Kota Semarang masih berfokus pada mempertahankan usaha dan mendapatkan keuntungan untuk kelangsungan produksi. Aspek keberlanjutan belum mendapat cukup perhatian. Penelitian ini bertujuan untuk melakukan penilaian keberlanjutan terhadap sistem produksi UKM Batik Kota Semarang menggunakan metode product-service system (PSS). PSS terdiri dari tiga dimensi keberlajutan yaitu lingkungan, sosial-budaya dan ekonomi yang masing-masing memiliki 6 kriteria. PSS bukan hanya menilai tingkat keberlanjutan tapi juga mengidentifikasi peluang pengembangan didasarkan dari peta sistem dan analisa SWOT. Perumusan rekomendasi menggunakan panduan berupa sebuah daftar periksa (check list). Selanjutnya, diagram kelayakan rekomendasi digunakan untuk menyeleksi dan menguji kelayakan rekomendasi yang diciptakan menggunaakan portofolio diagram. Penilaian keberlanjutan yang dilakukan memberikan hasil nilai rata â€“ rata 0,103 yang berada dalam kategori â€œrendahâ€. Rekomendasi yang dihasilkan untuk dimensi lingkungan antara lain menerapkan penggunaaan bahan baku dan air yang optimal, melakukan daur ulang dari limbah pewarna buatan, penggunaan bahan baku bio-degradable. Pada dimensi sosial budaya rekomendasinya adalah penggunaan alat pelindung diri bagi pekerja. Pada dimensi ekonomi direkomendasikan untuk mengidentifikasi kelompok sasaran, menerapkan strategi yang menghasilkan produk lebih menarik bagi pelanggan dan menciptakan diversifikasi dalam penawaran batik. Rekomendasi ini kemudian digambarkan dalam sebuah diagram berupa radar keberlanjutan

Menuju manufaktur berkelanjutan di Indonesia: Tantangan dan Kesempatan

Jessica Hanafi — Wed, 24 Aug 2016 11:47:52 +0000

Persaingan global mendorong Indonesia untuk memajukan ekonominya. Salah satu cara untuk menjawab tantanganÂ globalisasi ini adalah dengan menerapkan manufaktur berkelanjutan. Manufaktur berkelanjutan berawal dari manufaktur ramping, produksi bersih dan Life Cyle Assessment dengan memperhatikan keselamatan karyawan, konsumen dan masyarakat. Terdapat berbagai hambatan dalam implementasi manufaktur berkelanjutan. Indikator keberlanjutan suatu organisasi juga beragam, yang berdasar pada tiga aspek, yaitu ekonomi, sosial dan lingkungan. Pada makalah ini akan dibahas bagaimana isu manufaktur berkelanjutan akan dilihat dari ketiga perspektif, yaitu sisi industri, pemerintah dan akademia, khususnya di Indonesia.

Safety Management in an Oil Company through Failure Mode Effects and Critical Analysis

Benedictus Rahardjo — Thu, 09 Jun 2016 00:00:00 +0000

This study attempts to apply Failure Mode Effects and Criticality Analysis (FMECA) to improve the safety of a production system, specifically the production process of an oil company. Since food processing is a worldwide issue and self-management of a food company is more important than relying on government regulations, therefore this study focused on that matter. The initial step of this study is to identify and analyze the criticality of the potential failure modes of the production process. Furthermore, take corrective action to minimize the probability of repeating the same failure mode, followed by a re-analysis of its criticality. The results of corrective actions were compared with those before improvement conditions by testing the significance of the difference using two sample t-test. The final measured result is the Criticality Priority Number (CPN), which refers to the severity category of the failure mode and the probability of occurrence of the same failure mode. The recommended actions proposed by the FMECA significantly reduce the CPN compared with the value before improvement, with increases of 38.46% for the palm olein case study.

Potensi Kebijaksanaan Kontrak Pemeliharaan Mesin dalam Menunjang Keberhasilan Mekanisme Industri Pertanian

Hennie Husniah, Udjiana S. Pasaribu, A.H. Halim, B.P. Iskandar — Thu, 09 Jun 2016 00:00:00 +0000

In this paper we discuss a mathematical model of maintenance policy for certain type of agricultural equipments. It is assumed that the equipments are repairable and sold with two-dimensional warranty, i.e. a warranty with two scales of limit, such as the age of the equipment and the usage of the equipment. As an example in the case of automobile, the warranty is cease whenever the age of the automobile reaches 5 years or its mileage reaches 50.000 km, whichever occurs first. The model is intended to provide the best contract-based preventive maintenance (PM) strategy chosen from available options. A method to determine the optimal cost of service contract, both from user and producer view points, is presented. Numerical simulations reveal that the resulting optimal strategy depends on the level of the consumer usage pattern. In this paper we show that the selection of optimal policy is potential in supporting the performance of mechanization in agricultural industry in terms of choosing the best strategy to maintain agricultural equipments effectively (is able to reduce the failure rate of the equipment) with a minimal cost.

Model Persediaan pada Produk yang Mendekati Masa Kadaluwarsa: Mempertimbangkan Diskon Penjualan dan Retur

Laila Nafisah, Wellem Sally, Puryani Puryani — Thu, 09 Jun 2016 00:00:00 +0000

Most products are sold in Mirota Campus Supermarkets have perishable nature. One of the strategies undertaken in product sales is by providing discounts on products approaching expiry date. The closer to the expiration date, then the discounts given per unit will increase. Allows product pemasoks can in returns with the terms and conditions agreed. In this paper, developed a model multi-item inventory for a product that has a shelf-life of taking into account discounts and product returns. Completion of the model is done with optimization approach based on parameters that influence in this model. Numerical examples are given at the end of this paper to illustrate the model settlement algorithms.

Pengembangan Alat Pengukuran Kelelahan Mental Berbasis Uji Flicker

Yassierli Yassierli, Atya Nur Aisha, Azi Ginanjar Nugraha — Thu, 09 Jun 2016 00:00:00 +0000

Previous studies have been conducted to measure fatigue using flicker test. However, the validity of the device is still unknown empirically. This study proposed a modification of fatigue measuring apparatus based on flicker test. The modifications were developed from the framework of human factors product design, with the stages including analysis of the existing condition, operational concept, user requirements, performance criteria, system requirements, design prototyping, usability testing and final testing. The proposed apparatus consists of two main parts: a stimulus source and a control device as input. The stimulus is given by three lights with adjustable position and orientation angle. A LCD screen was provided to display status and result of the measurement. The control device consists of three buttons to respond the stimulus accordingly. Product testings were done through 1) a laboratory experiment with activities of critical reading and arithmetic complex and 2) a field study on a night bus driver. All the tasks selected represent works with a dominant mental workload. The laboratory experiments showed the range of Critical Flicker Fusion Frequency (CFFF) at work of 14-40 HZ, with the average decline of CFFF values of 5.3 Hz in arithmetic complex and 4.8 Hz in critical reading activities. The study on the night bus driver resulted in CFFF value range of 18-40 Hz with the average delta CFFF of 8.97 Hz. Both testings suggest that flicker test with CFFF indicators can be used to measure mental fatigue. In addition, the proposed framework used in this design development can be used as a reference in designing various products by taking human factor aspects as the focus such as user needs and user limitations.

Change Management Perspectives in an ERP Module Implementation: A Case Study in a Telecommunication Company

Tota Simatupang, Rajesri Govindaraju, Reni Amaranti — Thu, 09 Jun 2016 00:00:00 +0000

Successful Enterprise Resource Planning (ERP) projects require change management to support the integration of the ERP systems into work environment because ERP impleÂ¬menÂ¬tations involve lots of changes on technical infrastructures, business processes, organization structure, rules and skills of people in the organization. This study was aimed to explain the challenges in implementing an ERP module in a Indonesian telecommunication company, focusing on the change management process involves in the project. A case study at a teleÂ¬comÂ¬munication company was used to collect empirical data and to analyses important aspects of project arrangements that will have an impact on the change management process accompanying the ERP implementation project. The following two aspects of changes were analyzed as the impact of ERP implementation: changes in individual behaviors and changes in the organisational practices. Based on the empirical study, two important aspects of change management effectiveness in the project and post-project stage were highlighted: alignment of the organization structure to support IT-business collaboration and alignment of employee orientation towards effective use of ERP systems. Besides, this study also highlighted that it is important to plan and execute change management process in the post-project stage to obtain benefits from ERP implementation.

Pengembangan Framework untuk Mengukur Tingkat Keberhasilan Implementasi Reverse Logistics

Farida Pulansari, Dwi Sukma Donorianto, Iriani Iriani — Wed, 16 Dec 2015 00:00:00 +0000

Electronic Waste (E-waste) is growing attention at the end of this decade. E-waste must be managed properly. E-waste has a negative impact on the environment. E-waste contain B3 (Bahan Berbahaya dan Beracun). Reverse Logistics (RL) is one approach that able to solve these problems. The use of secondary materials through the process of remanufacturing, recycling, refurbishing, recondition are strategy to minimizing the number of e-waste. Many companies claim successfully implementing of RL. However, there are no clear indicators or parameters to assess the success of RL implementation. In this research we propose the design of reverse logistics maturity framework. Grounded Theory (GT) is chosen to design this framework. GT is a research methodology involving the construction of theory based on phenomena. This framework will be divided into five levels of maturity: Level Conventional, Managed, Developed, Innovative and Optimized. Results of research from three consumer electronics companies were in the Level Managed.

Model Optimisasi untuk Penjadwalan Ulang Perjalanan Kereta Api

Suprayogi Suprayogi, Hery Ramdhani — Wed, 16 Dec 2015 00:00:00 +0000

This paper discusses the train rescheduling problem due to disturbances. The train rescheduling problem discussed in this paper is taken from a real train network of DAOP II Bandung in Jawa, Indonesia. The train network consists of block sections including unidirectional double-tracks and bidirectional single-tracks. There are some connections among trains because they use same rolling stocks. A mixed integer linear programming model is formulated to represent the problem. Main decision variables of the model are new departure and arrival times due to the disturbance. The objective function to be minimized is the total weighted delay. The model is examined using a hypothetical instance for four disturbance cases. Numerical experiments show that the model can represent the problem under study