Number Of Kanbans Research Articles

Perancangan Sistem Kanban untuk Mengurangi Keterlambatan Komponen Rear Spar

Kanban literally means a visual note that usually takes the form of a card placed in a rectangular vinyl envelope and containing part information sent from one process to the previous process. The application of kanban is believed to optimize the production process. In this study, the kanban system was designed to reduce delays in Rear Spar components at PT. XYZ, a manufacturing company that produces aircraft, such as NC212 aircraft. The Rear Spar component on NC212 aircraft is often delayed. The main cause of Rear Spar delays is the unclear information and material flow so that operators on the Fabrication Line do not know when parts must be in the Assembly Line so that there is no priority for part work and some parts are late to be delivered to the Assembly Line. The design of the kanban system is carried out using the Constant-Quantity Withdrawal System method which consists of four stages, namely: calculating the lead time, calculating the necessary number of parts during the lead time, calculating safety inventory, and calculating the number of kanban cards. After calculating the number of kanban cards, the number of Assembly Line kanban cards to the Assembly Store is one sheet of production kanban and one sheet of withdrawal kanban. As for the number of Assembly Store kanban cards to the Fabrication Line is one sheet of production kanban for each part. The design of the kanban system is continued with the design of the kanban card, kanban mechanism, and kanban post position. The results obtained after simulating the design results using the simulation scenario made by the author are that the part making process is reduced by 41 minutes.

Using the kanban system as an effective tool for organizing the transportation of dairy raw materials

The paper considers approaches to providing the enterprise with the required raw materials or semi-finished products. The general scheme of the milk raw material transportation cycle was analyzed. According to one approach, the supply system of raw materials can be represented by three constants, based on which several of their relations can be established, allowing us to describe the supply system much better. It is emphasized that the total duration of the cycle for each supplier is individual and depends on the demand indicator and the volume of the batch of the product or raw material. However, each product or raw material supplier's different cycle times do not allow them to be consolidated to build a stable delivery route. It is essential to achieve the required delivery frequency with maximum vehicle loading. The need to use the " heijunka board" to organize the efficient operation of routes for the transportation of dairy raw materials by the enterprise's employees was analyzed. Such a tool allows one to visualize dairy raw materials' transportation routes and ensure explicit control. For this, a heijunka board and supplier kanban cards are used, which form a graphic representation of transport routes in the corresponding time interval. Policy directions for determining the frequency of transportation of raw materials or semi-finished products are highlighted. It is proved that the optimal order policy must satisfy the zero-order property, and the time between orders can be calculated based on the amount of stock in the warehouse and the speed of their use, which will correspond to the demand indicator d and will reach zero after f orders. The kanban system allows optimal results in combination with the heizunk method, which balances the delivery time of raw materials or products as much as possible. Several models for the analysis of the heizunk system are considered. The common feature of these methods is the search for the optimal size of the buffer stock to ensure the maximum efficiency of production facilities while minimizing losses. The total number of kanbans for the system is decisive because this indicator determines the effectiveness of their adaptation to changes in production conditions. Keywords: kanban, system, heizunk method, loss minimization, order.

Editorial: Toyota Production System practices asFast‐and‐Frugalheuristics

Editorial: Toyota Production System practices as<scp>Fast‐and‐Frugal</scp>heuristics

System dynamics modelling of fixed and dynamic Kanban controlled production systems: a supply chain perspective

PurposePull production systems have received much attention in the supply chain management environment. The number of Kanbans is a key decision variable in the pull production system as it affects the finished goods inventory (FGI) and backorders of the system. The purpose of this study is to compare the performance of the fixed and dynamic Kanban systems in terms of operational metrics (FGI and backorders) under the demand uncertainty.Design/methodology/approachIn this paper, the system dynamics (SD) approach was used to model the performance of fixed and dynamic Kanban based production systems. SD approach has enabled the feedback mechanism and is an appropriate tool to incorporate the dynamic control during the simulation. Initially, a simple Kanban based production system was developed and then compared the performance of production systems with fixed and dynamic controlled Kanbans at the various demand scenarios.FindingsFrom the present study, it is observed that the dynamic Kanban system has advantages over the fixed Kanban system and also observed that the variation in the backorders with respect to the demand uncertainty under the dynamic Kanban system is negligible.Research limitations/implicationsIn a just-in-time production system, the number of Kanbans is a key decision variable. The number of Kanbans is mainly depended on the demand, cycle time, safety stock factor (SSF) and container size. However, this study considered only demand uncertainty to compare the fixed and dynamic Kanban systems. This paper further recommends researchers to consider other control variables which may influence the number of Kanbans such as cycle time, SSF and container size.Originality/valueThis study will be useful to decision-makers and production managers in the selection of the Kanban systems in uncertain demand applications.

Implementing lean paradigm in an Indian foundry facility: a case study

This article seeks to establish the effectiveness of lean manufacturing in eliminating the hidden wastes, maintaining better inventory control and reducing the total production time. A large Indian foundry facility is utilised to illustrate the adopted approach. Firstly, current state mapping is prepared to have the knowledge of the existing procedure followed in the production of castings. In addition, relevant data such as, cycle time, changeover time, percentage of defects, percentage downtime and inventory in between the processes are collected for each process. Further, the future state map is created, after amending the entire process, by adopting the methodology proposed by Rother and Shook (1999). Additionally, the required buffer size (number of Kanbans) at each stage and the sequence of production are also estimated by adopting the method advocated by the Smalley (2004). Finally, improvement is accounted in terms of reduced lead time of the process.

Implementation of kanban to improve efficiency of a manufacturing system subject to bottlenecks

The strategy of a kanban is to optimise the inventory level by minimising the inventory holding cost and the back order level. The number of kanbans determines the total inventory has been used for manufacturing. A bi-criteria objective performance consisting of weighted tardiness and weighted work-in-process has been utilised for assessment. The bottleneck is a hurdle to reaching the objective. The major role of the projected paper is evolving the model to enhance kanban system in a product manufacturing industry by various optimisation methods by considering the hurdles due to bottleneck operation. These industrialised models can be used to enhance the system by minimising the tardiness and work in progress cost in the flow of product at the restricted access point with kanban production scheme. From the solutions attained, the optimal kanban size with minimum tardiness and WIP cost is identified by harmony search (HS) optimisation algorithm.

Vehicle routing problem in a kanban controlled supply chain system considering cross-docking strategy

This paper considers an inventory-routing problem in a distribution network in which kanban is used as a means to implement just-in-time strategy. There are a set of part suppliers and cross-docks in this network, which provide parts for an assembly plant. A novel mixed integer non-linear programming formulation is developed for the problem in which the optimum number of kanbans is determined considering inventory and transportation cost. In the other word, this research aims at reducing the level of inventory and transportation cost in a kanban controlled supply chain system, in which the number of kanbans is to be determined optimally considering demand from suppliers and geographical distribution of them. A fleet of vehicles is applied to transport kanbans from suppliers to the assembly plant via two transportation strategies: direct shipment and shipment through cross-docks (indirect shipment). In the second strategy, it is possible to have routes between suppliers. The proposed problem is NP-hard based on literature, thus a memetic algorithm is introduced to solve it. Solving several examples reveals that the solving method significantly outperforms GAMS/CPLEX in reducing objective value and computational time.

The Determination of Production and Distribution Policy in Push-Pull Production Chain with Supply Hub as the Junction Point

The development of technology causes the needs of products and services become increasingly complex, diverse, and fluctuating. This causes the level of inter-company dependencies within a production chains increased. To be able to compete, efficiency improvements need to be done collaboratively in the production chain network. One of the efforts to increase efficiency is to harmonize production and distribution activities in the production chain network. This paper describes the harmonization of production and distribution activities by applying the use of push-pull system and supply hub in the production chain between two companies. The research methodology begins with conducting empirical and literature studies, formulating research questions, developing mathematical models, conducting trials and analyses, and taking conclusions. The relationship between the two companies is described in the MINLP mathematical model with the total cost of production chain as the objective function. Decisions generated by the mathematical models are the size of production lot, size of delivery lot, number of kanban, frequency of delivery, and the number of understock and overstock lot.

Designing number of Kanban in glove box assembly

For many decades, Just-In-Time manufacturing and lean manufacturing have adopted kanban system as a mean to control inventory and production. A number of tagged kanban cards represents inventory of the system, whereas untagged kanban cards equate to production orders. The ideal conditions are a consistent product mixed with a small production lot size and minimum setup time. Such conditions are difficult to obtain even in many automotive assembly lines similar to a case study. The case study assembly line is a glove box assembly production line that assembles two plastic parts and wields them together with a vibration machine after positioning in a mold designed for different products. Because of storage equipment, each kanban card represents 60 identical glove boxes. Therefore, a production engineer re-schedules the production planning to minimize the numbers of changeover without any effect on downstream. This ad hoc production scheduling leads to urgent production orders and interruption of lot size. As a result, the factory embeds historical data into a computer simulation that accounts for current molds, receiving time, and numbers of pending kanban cards, as well as number of storage equipment. The results of this simulation reveals that scheduling criteria and suggest a suitable lot size if the factory decides to change a storage equipment.

Optimizing the Number of Kanbans for Two-stage Production System Based on Queuing Theory

Optimizing the Number of Kanbans for Two-stage Production System Based on Queuing Theory

MENJAMIN KUALITAS VAKSIN DENGAN MANAJEMEN RANTAI DINGIN

&lt;p&gt;Kemajuan Konsep paradigma sehat di dalam pembangunan kesehatan adalah pembangunan kesehatan yang lebih memprioritaskan upaya promotif dan preventif dibandingkan kuratif dan rehabilitatif. Program imunisasi merupakan salah satu upayapreventif yang telah terbukti sangat efektif menurunkan angka kesakitan dan angka kematian serta kecacatan pada bayi dan balita (Ditjen Bina Kefarmasian dan Alat Kesehatan Depkes RI, 2009).&lt;/p&gt;&lt;p&gt;Vaksin merupakan komponen utama dalam program imunisasi dimana ketersediaannya harus terjamin sampai ke sasaran. Sesuai dengan PP 38 tahun 2007 tetang kewenangan pemerintah dan kewenangan provinsi sebagai daerah otonomi dan Peraturan Menteri Kesehatan No. 439/ MENKES/ PER/ VI/ 2009 tentang Perubahan Kedua Atas Peraturan Menteri Kesehatan No. 1575/ MENKES/PER/XI/2005 tentang Organisasi dan Tata Kerja Depkes, antara lain menyebutkan bahwa kewenangan pemerintah pusat menyediakan obat esensial tertentu dan obat sangat esensial untuk pelayanan kesehatan dasar. Selain itu pemerintah juga menjamin ketersediaan bahan imunisasi yang aman, bermutu, efektif, terjangkau, dan merata bagi masyarakat untuk upaya pengendalian penyakit menular melalui imunisasi (Undang - Undang Kesehatan RI No. 36/09).&lt;/p&gt;&lt;p&gt;Sejak ditemukannya vaksin dan tehnik pembuatan vaksin yang semakin berkembang pesat hingga saat ini, ada satu hal yang mutlak harus ada bila kita berbicara tentang penyimpanan vaksin, yaitu rantai dingin atau cold chain, yaitu suatu sistim penyimpanan vaksin dengan suhu antara 2 – 8 derajat Celsius, agar supaya komponen dalam vaksin yang bersifat bioaktif tidak mengalami kerusakan karena suhu yang tinggi atau suhu yang terlalu rendah, sehingga dengan suhu penyimpanan yang tepat, potensi proteksi vaksin akan tetap terjaga maksimal hingga waktu yang telah ditentukan oleh pabrik pembuat vaksin, yang ditentukan dengan yang disebut Expiration Date atau Waktu Kadaluarsa vaksin.&lt;/p&gt;

Implementation of Kanban to improve efficiency of a Manufacturing System subject to bottlenecks

The strategy of a kanban is to optimise the inventory level by minimising the inventory holding cost and the back order level. The number of kanbans determines the total inventory has been used for manufacturing. A bi-criteria objective performance consisting of weighted tardiness and weighted work-in-process has been utilised for assessment. The bottleneck is a hurdle to reaching the objective. The major role of the projected paper is evolving the model to enhance kanban system in a product manufacturing industry by various optimisation methods by considering the hurdles due to bottleneck operation. These industrialised models can be used to enhance the system by minimising the tardiness and work in progress cost in the flow of product at the restricted access point with kanban production scheme. From the solutions attained, the optimal kanban size with minimum tardiness and WIP cost is identified by harmony search (HS) optimisation algorithm.

A hybrid push/pull design of kanban systems during production ramp-up phase

This paper investigates a hybrid push/pull design of kanban systems that better fulfils the requirements posed by uncertain environments during production ramp-up phase. Rapid surges in customer demand after start-of-production of new products impact the operations performance of material flows and stock levels. We address this issue and demonstrate that an incremental planning model, allowing fluctuations in the number of kanbans, provides viable planning results. In addition, we select possible kanban system environments by using Monte Carlo simulation. This approach proactively allows the operations manager to cope better with processing times and demand variations. In addition, it may reveal potential weakness in standard approaches for kanban system planning. Our research is based on a real case study data of the German auto industry.

Determining the number of kanbans for dynamic production systems: An integrated methodology

Determining the number of kanbans for dynamic production systems: An integrated methodology

Determining the number of kanbans for dynamic production systems: An integrated methodology

Determining the number of kanbans for dynamic production systems: An integrated methodology

A simulative approach for evaluating alternative feeding scenarios in a kanban system

In accordance with the lean production philosophy, an assembly line may be supplied by means of a kanban system, which regulates and simplifies the flow of materials between the lines and the warehouses. This paper focuses on evaluation of feeding policies that differ from each other in term of the number of kanbans managed per feeding tour. A pure cost-based approach is thus proposed, which considers both inline inventories along with handling costs proportionate to the number of operators involved in the parts-feeding process. A multi-scenario simulative approach is applied in order to establish the number of operators required to avoid inline shortages. The scenario minimising total cost is then selected. The innovation introduced is a model for describing kanban arrivals and their requests for feeding, improving the potential of the simulation to describe real-life environments. Lastly, a case study from the automotive industry is presented in order to highlight the applicability of the proposed approach as well and the effects of alternative feeding policies on the total cost incurred.

A mathematical programming model for cellular manufacturing system controlled by kanban with rework consideration

This research studies the cellular manufacturing system (CMS) controlled by kanban mechanism which defective items are produced in any production run of each product and rework is carried out to transform them into serviceable items. We consider and compare two different policies for rework where in the first policy rework is completed within the same production cycle and in the second policy rework done after N production cycles. Recently Aghajani et al. (2012) explain policy 2 and proposed a mixed-integer nonlinear programming (MINLP) model for this policy. In order to minimize total cost, MINLP model was developed for policy 1 to find simultaneously the optimal number of kanban, batch size, and number of batches. The cost function includes the cost of setup, holding, and transportation. Due to the high combinatorial structure of the problem, particle swarm optimization (PSO), and simulated annealing (SA) algorithms as meta-heuristic methods are proposed to solve the problem and numerical experiments are conducted to demonstrate the efficiency of the proposed algorithms. It is shown that both PSO and SA result are in a near optimal solution but the PSO algorithm gives a better performance than the SA method. Also, sensitivity analysis is carried out to study the effect of defective rate, holding cost, and setup cost variations on the total system cost is discussed the performance of these policies in different conditions.

Kanban-driven parts feeding within a semi-automated O-shaped assembly line: a case study in the automotive industry

Purpose – The aim of the present work is to provide a case study where lean production (LP) techniques are implemented in a semi-automated assembly line with O-shaped (closed-loop) layout configuration. The action research has been conducted within an assembly line for automotive components. The work aims to provide insights on the impact of loop layout features with respect to lean principles’ application; operative solutions related to some logistic limit of loop layout; and how kanban technique can be adapted to an O-shaped layout. Design/methodology/approach – The main research methodology is based on action research within an assembly line of oil pumps. The two research questions find answer through literature analysis and implementation of LP in the O-shaped layout. In the A3 step, we identify the main weak points of a loop layout also under the perspective of operators’ feeling. The analysis of the main constraints is conducted in this step, with respect to the most common layout used within LP adoption. Steps A4 and A5 answer to RQ2 by an on-field results’ analysis. Findings – The use of an O-shaped layout may allow to improve ergonomic conditions for workers; to better organize parts feeding through slides and chutes because of the presence of operators outside the line. The new approach to determine the number of withdrawal kanban potentially extends the findings of Tardif et al. (2012): the minimum of the objective function is reached with a higher number of withdrawal kanbans. Research limitations/implications – The approach is applied within a stand-alone line, while in several industrial contexts, we may find several of these lines in the same shop floor. In this case, LP implementation would cope with the several kanban cards circulating, the over-saturation of the logistic operator in supplying all the lines with smaller quantities of materials. Practical implications – The action research resulted in the introduction of a new concept of supermarket, conceived as a decoupling buffer that lies near the line and in the review feeding devices, with the adoption of bins and operators’ feeding chutes. Parts’ feeding systems is reorganized with a two levels of withdrawal kanban. The introduction of line supermarket and the change of supply policies from pallets to bins contributed to the strong reduction of average work-in-progress. Yet, the double-withdrawal kanban and the small quantities supplied may cause an increase of material handling times and meters covered by operators. Social implications – Better working condition of the line operators because of the presence of ergonomic chutes for parts’ feeding. In contrast, we observed a high saturation of logistic operator because of the small quantities of components supplied on the line, with an increased stress of this worker. Originality/value – A decoupled withdrawal kanban (DWK) is developed. In DWK, the first withdrawal is issued to the supermarket that serves the line. The second withdrawal kanban is issued from the supermarket to the central warehouse. Within DWK, we propose a modified dimensioning formula through minimization of the objective function Z(k). Parts’ feeding is now organized with sliding chutes on operators’ workstations to collect components in accordance to kanban dimensioning.

Mathematical Approach for Determining the Number of Kanbans: A Step towards Non-Stock Production in Manufacturing Scenario

Just-in-time (JIT) production is a philosophy that calls for reducing work-in-process (WIP) inventory to aid process improvement and reduce process variability. Kanban act as the nerve of a JIT production system whose functions is to direct materials just-in-time to workstations in stages of manufacturing, and pass information as to what and how much to produce. Indeed, the number of kanbans between two adjacent workstations decides the inventory level of that pair of workstations. With the objective of minimizing WIP inventory level, is developed for deciding the optimum number of kanbans. In the present work the mathematical model for calculating optimum number of kanbans and solution procedure are illustrated with a numerical example.

Análise do impacto da variabilidade de fluxo no dimensionamento de kanbans

O objetivo deste artigo é analisar os efeitos da variabilidade de fluxo, preconizada pela Factory Physics, no dimensionamento de Kanban em sistemas produtivos. A variabilidade de fluxo pressupõe que a variabilidade existente nas atividades executadas por um processo é dissipada ao longo de todo o fluxo produtivo do sistema, causando variações no lead time, no nível de estoques em processo e na disponibilidade de equipamentos, entre outros. Para conduzir a investigação, foi criado um modelo didático de simulação computacional por eventos discretos. O modelo proposto visa apresentar os possíveis impactos provocados pela variabilidade de fluxo no sistema produtivo no dimensionamento do número de cartões Kanban, a partir dos resultados fornecidos por dois cenários distintos investigados. Os principais resultados da pesquisa permitem evidenciar que, comparando os dois cenários desenvolvidos para o modelo, a presença de variabilidade no sistema produtivo causou um aumento médio de 32% no número de cartões Kanban (p=0,000). Isso implica que, em sistemas produtivos reais, o estudo de dimensionamento de Kanbans deveria contemplar as variabilidades individuais das operações, fato por vezes relegado a um pressuposto na formulação da literatura que trata da definição do número de Kanbans, oportunizando assim o desenvolvimento de pesquisas futuras nesse sentido.