Model Penentuan Nilai Target Functional Requirement Berbasis Utilitas

In a product design and development process, a designer faces a problem to decide functional requirement (FR) target values. That decision is made under a risk since it is conducted in the early design phase using incomplete information. Utility function can be used to reflect the decision maker attitude towards the risk in making such decision. In this research, we develop a utility-based model to determine FR target values using quadratic utility function and information from Quality Function Deployment (QFD). A pencil design is used as a numerical example using quadratic utility function for each FR. The model can be applied for balancing customer and designer interest in determining FR target values. Keywords: Optimization, quadratic utility, risk, functional requirement

Usulan Konsep Peningkatan Pelayanan Jasa di LBPP LIA Surakarta dengan Menggunakan Model SERVQUAL dan Metodologi Quality Function Deployment

This research is aimed to to identified customers’ needs in LBPP LIA Surakarta. Based on these identified customers’ need then the pre-concept of quality improvements in LBPP LIA Surakarta is made. Model that is used to identified customers’ needs is SERVQUAL while the methodology that is used to form the deployment is Quality Function Deployment (QFD), beside the use of factor analysis to identify factors which are influenced the quality service in LBPP LIA Surakarta. Keywords : Service, SERVQUAL, QF

Sistem Pakar untuk Pemilihan Unit Gawat Darurat Rumah Sakit di Kota Surakarta

Abstrak Makalah ini menyajikan sistem pakar untuk pemilihan unit gawat darurat rumah sakit di Kota Surakarta. Sistem ini dapat membantu tenaga medis saat menangani pasien gawat darurat untuk mengambil keputusan pemilihan rujukan ke rumah sakit yang tepat berdasarkan kondisi pasien dan ketersediaan sumber daya rumah sakit. Sistem ini berbasis website dan dapat diakses menggunakan telepon genggam. Sistem pakar ini dibangun atas model keputusan berbasis pengetahuan (knowledge base), basis data, dan antarmuka. Model keputusan berisi aturan (rule) dalam penentuan rumah sakit berdasarkan kondisi pasien dan data ketersediaan sumber daya rumah sakit serta data estimasi waktu tempuh tercepat sesuai peta digital Kota Surakarta yang diolah menggunakan sistem informasi geografis. Representasi pengetahuan disimpan menggunakan production rule dan mesin inferensi menggunakan metode runut maju (forward chaining). Hasil penelitian menunjukkan bahwa sistem pakar dapat bekerja dengan baik dalam membantu tenaga medis untuk memilih unit gawat darurat rumah sakit. Kata kunci: sistem pakar, pemilihan unit gawat darurat rumah sakit

Penjadwalan Pekerjaan pada No-Wait Flowshop dengan Kriteria Minimasi Total Waktu Tinggal Aktual Menggunakan Algoritma Genetik

This research uses genetic algorithm for no-wait flowshop scheduling problem. The shop requires the condition that each job be processed without any interruptions on all m machines and between two consecutive machine. This means that the start of processing a job on a given machine may be delayed in order to make the completion of the job on the machine coincide with this beginning of processing the job on the subsequent machine. The objective for the model is to minimize total actual flow time accommodating the condition that job to be processed arrive at the shop at any times when needed and the condition that the completed job be delivered at a common due-date. Genetic algorithm is randomly and structured search to find optimal solution. Numerical experience shows that for a given scheduling problem, genetic algorithm solution better than before (Yuniaristanto, 2001). Keywords : actual flowtime, genetic algorithm, no-wait flowsho

Determination Inventory Level for Aircraft Spare Parts Using Continuous Review Model

In this paper, we determine ordering quantity and reorder point for aircraft consumable spare parts. We use continuous review model to propose a spare part inventory policy that can be used in a aircraft maintenance company in Indonesia. We employ ABC classification system to categorize the spare parts based on their dollar contribution. We focus our research on managing the inventory level for spare parts on class A and B which commonly known as important classes. The result from the research indicates that the continuous review policy gives a significant amount of saving compared to an existing policy used by the company

Perancangan Setting Level Optimal dan Penentuan Quality Loss Function pada Pembuatan Tegel dengan Metode Taguchi

Taguchi method is one of methodology that used in off-line quality control activity on the product and process design phase. Tile company that made flowers motif tile which have 30 cm long, 30 cm wide and 3.5 cm thickness often found a product that have under company product quality standard. The aim’s of the research are to define the influence factors of quality design, to determine the optimum conditions of control factors so that the product is least sensitive to uncontrollable factors (noise factors) such a wear, aging and ambient conditions and to count quantitative evaluation of quality loss function due to functional variation. Keywords : Taguchi methods, optimum setting level and quality loss function

Two stages optimization model on make or buy analysis and quality improvement considering learning and forgetting curve

Purpose: The aim of this research is to develop a two stages optimization model on make or buy analysis and quality improvement considering learning and forgetting curve. The first stage model is developed to determine the optimal selection of process/suppliers and the component allocation to those corresponding process/suppliers. The second stage model deals with quality improvement efforts to determine the optimal investment to maximize Return on Investment (ROI) by taking into consideration the learning and forgetting curve. Design/methodology/approach: The research used system modeling approach by mathematically modeling the system consists of a manufacturer with multi suppliers where the manufacturer tries to determine the best combination of their own processes and suppliers to minimize certain costs and provides funding for quality improvement efforts for their own processes and suppliers sides. Findings: This research provides better decisions in make or buy analysis and to improve the components by quality investment considering learning and forgetting curve. Research limitations/implications: This research has limitations concerning investment fund that assumed to be provided by the manufacturer which in the real system the fund may be provided by the suppliers. In this model we also does not differentiate two types of learning, namely autonomous and induced learning. Practical implications: This model can be used by a manufacturer to gain deeper insight in making decisions concerning process/suppliers selection along with component allocation and how to improve the component by investment allocation to maximize ROI. Originality/value: This paper combines two models, which in previous research the models are discussed separately. The inclusions of learning and forgetting also gives a new perspective in quality investment decision.Peer Reviewe

Developing Inventory Policy for Aircraft Spare Parts using Periodic Review Model

This research is conducted to develop inventory policy of aircraft consumable spare parts which are needed on aircraft maintenance activity. In this research, we used periodic review model to determine the optimal policy of aircraft spare parts inventory. By using the periodic review model, we find optimal period of inventory review and maximum level of inventory.  The optimal decision is determined based on the minimum total cost. We have classified consumable spare parts using ABC method to categorize them based on their dollar contribution and demand frequency. Therefore in this research, we focus on managing the inventory level for spare parts on class C. The result from this study shows that the proposed periodic review policy result in lower total inventory cost compared the the company policy. The proposed policy gives an average saving 35.38 %. Keywords: Inventory, spare part, periodic review, inventory review, maximum level, ABC method

Order Allocation Model Considering Transportation Alternatives and Lateral Transhipment

Intense competition among companies encourages them to provide the best quality of products in competitive price. It is important for company to manage supply chain properly in order to achieve that. Selecting the best reliable supplier is the key to reduce purchasing cost, increase customer satisfaction and improve the competitive ability. In this study, we develop an order allocation model in multi echelon environment which includes supplier, manufacturer, and retailer. We consider transportation alternatives for the shipment from supplier to manufacturer and also the shipment from manufacturer to retailer. This model allows lateral transshipment between retailers.  A Mixed Integer Linear Programming (MILP) is used to model the system. Sensitivity analysis is conducted at the end of the research. The result shows that the retailer demand, lead time, material variable price are sensitive to the objective function while the transportation costs from supplier to manufacturer, from manufacturer to retailers, and between retailers are not sensitive to the objective function. Retailer demand parameter is also sensitive to all decision variables. The transportation cost from supplier to manufacturer, material prices, and lead time are sensitive to the order allocation from manufacturer to supplier, while transportation cost from manufacturer to retailers and transportation cost between retailers are sensitive to the allocation of product sent from the manufacturer to retailers and the allocation of product sent between retailers

An Integrated Optimization Model for Product Design and Production Allocation in a Make to Order Manufacturing System

A mechanical assembly consists of several components to perform an intended function. At the design stage, the intended function must be converted into critical product dimensions. After determining the dimensions, a designer must determine the assembly tolerance and allocate this tolerance to the tolerances of the corresponding components. After determining the optimal tolerances, process selection must be conducted along with production allocation to the selected process. There are three aspects in commercial competition that must be considered by a manufacturing company: cost, quality, and delivery. The aim of this research is to develop an optimization model for process selection for a make to order company to minimize manufacturing cost, quality loss, and lateness cost. The model attempts to determine optimal tolerance and production allocation, which takes into consideration the production capacity and process sequence. Hence, the model attempts to include not only the product design decision, but also to solve the process selection and allocation problems. A numerical example is provided to show the implementation of the model