<p>Detta examensarbete har utförts på Rimaster AB i Rimforsa, vars huvudsakliga verksamhet är legotillverkning inom elektronik och mekatronik. Rimaster AB har cirka 140 anställda och omsätter cirka 116 MSEK. Den största delen av tillverkningen är manuell och all produktion sker mot kundorder. Företaget upplever att produktionsflödet är ojämnt och därmed även kapacitetsutnyttjandet. Dessutom är kapitalbindningen hög, både i råvarulager och i färdigvarulager. Syftet med detta arbete är därför att genom en förbättrad styrning av lager och produktion minska kapitalbindningen samt uppnå ett jämnare kapacitetsutnyttjande.</p><p>Kostnaden för kapitalbindningen bestäms genom att en lagerränta för respektive lagerställe tas fram. För råvarulagret beräknas lagerräntan till 15,8 procent och för färdigvarulagret 16,9 procent. Totalt ger detta en årlig kostnad för kapitalbindning på 2,4 MSEK. Utöver detta ska lagerräntan användas till att fatta korrekta beslut vid lagerstyrning, till exempel vid beräknande av inköpskvantiteter.</p><p>Vid en analys av råvarulagret identifieras ett antal artikeltyper som i sin tur ligger till grund för en klassificering av de lagerförda artiklarna. En artikelklass som stora delar av kapitalbindningsproblematiken kan hänföras till är artiklar med låg behovsfrekvens i kombination med leverantörernas minimala orderkvantiteter. För att minska detta problem rekommenderas ett fördjupat leverantörssamarbete i syfte att göra orderkvantiteterna mindre. För övriga artikelklasser föreslås en differentierad lagerstyrning som ett verktyg för att få kontroll över lagret. Kapitalbindningen i färdigvarulagret beror främst på att kunden, genom avtal, bestämmer hur deras ledtidskrav ska uppfyllas. Detta beslut bör istället fattas av Rimaster AB och baseras på kundorderpunktens placering.</p><p>Det ojämna kapacitetsutnyttjandet beror bland annat på att produktionen är uppdelad i flera mindre grupper med kundfokus. Dessutom stämmer inte produktionsgrupperna överens med de grupper som använts planeringsmässigt. Av denna anledning föreslås ett nytt produktionsflöde där fyra produktorienterade slutmonteringsgrupper skapas, dessa bildar dessutom planeringsgrupper. Genom denna aggregering av resurser skapas förutsättningar för ett jämnare produktionsflöde och därmed även ett jämnare kapacitetsutnyttjande. Samtidigt föreslås ett nytt detaljplaneringssystem med funktionalitet enligt Workload Control-konceptet för att möjliggöra korta och säkra ledtider och en begränsad mängd produkter i arbete.</p><p>En ytterligare bidragande orsak till det ojämna produktionsflödet är att produktionsbatcherna är stora, trots att ställtidsandelen normalt sett är låg. Detta beror på att batchstorleken normalt likställs med storleken på en kundorder. Följaktligen föreslås en minskning av batchstorlekarna vilket förutom att bidra till ett jämnare flöde även medför kortare produktionsledtider.</p> / <p>This Master Thesis has been carried out at Rimaster AB in Rimforsa, a sub-contractor in electronics and mechatronics. Rimaster AB has 140 employees and an approximate annual turnover of 116 MSEK. The main part of the production consists of manual work and is carried out on receipt of customer orders. The company perceives a fluctuating flow in the production and consequently fluctuations in the capacity utilization. Furthermore there is a considerable capital tye-up in the inventory of raw materials as well as in the inventory of finished goods. Therefore the purpose of this Master Thesis is to achieve levelled capacity utilization and less capital tied-up through an improved management of inventory and manufacturing.</p><p>An inventory holding cost is calculated for the inventories respectively to determine the cost of capital tied-up. For the inventory of raw materials the cost is 15.8 percent of the annual average inventory value, and for the inventory of finished goods the cost is 16.9 percent. This yields an annual cost of 2.4 MSEK. Furthermore the inventory holding cost should be used in decisions regarding inventory management, e.g. when calculating order quantities.</p><p>When analyzing the inventory of raw materials a number of types of stock items are identified. These types form the foundation of a classification of the stock items. A significant part of the capital tied-up relates to stock items with low demand combined with minimum order quantities from the suppliers. An improved co-operation with the suppliers in order to reduce these quantities is therefore recommended. For the remaining classes of stock items a differentiated inventory control system is proposed. In the inventory of finished goods the capital tied-up is mainly a consequence of customers requiring, by contract, how their demanded lead time shall be fulfilled. Instead this should be decided by Rimaster AB based on the position of the order penetration point.</p><p>One reason to the fluctuating capacity utilization is that the production is divided into several sub-groups with customer focus. Furthermore these groups do not correspond to the groups used for production planning. A new production flow is therefore proposed with four product-oriented final assembly groups. These new groups should also be used for production planning. Through this aggregation of production resources it is possible to achieve a levelled production flow and hence a levelled capacity utilization. In combination with the measures mentioned above, a new production activity control system, in accordance to the Workload Control concept, is proposed. This control system enables short and safe lead times and a limited amount of work in progress.</p><p>Another reason to the fluctuating capacity utilization, caused by a fluctuating production flow, is the use of large batches despite short set-up times. The size of a batch is normally equal to the size of a customer order. Consequently a reduction of the batch sizes is proposed in order to achieve a levelled production flow and shortened production lead times.</p>

Detta examensarbete har utförts på Rimaster AB i Rimforsa, vars huvudsakliga verksamhet är legotillverkning inom elektronik och mekatronik. Rimaster AB har cirka 140 anställda och omsätter cirka 116 MSEK. Den största delen av tillverkningen är manuell och all produktion sker mot kundorder. Företaget upplever att produktionsflödet är ojämnt och därmed även kapacitetsutnyttjandet. Dessutom är kapitalbindningen hög, både i råvarulager och i färdigvarulager. Syftet med detta arbete är därför att genom en förbättrad styrning av lager och produktion minska kapitalbindningen samt uppnå ett jämnare kapacitetsutnyttjande. Kostnaden för kapitalbindningen bestäms genom att en lagerränta för respektive lagerställe tas fram. För råvarulagret beräknas lagerräntan till 15,8 procent och för färdigvarulagret 16,9 procent. Totalt ger detta en årlig kostnad för kapitalbindning på 2,4 MSEK. Utöver detta ska lagerräntan användas till att fatta korrekta beslut vid lagerstyrning, till exempel vid beräknande av inköpskvantiteter. Vid en analys av råvarulagret identifieras ett antal artikeltyper som i sin tur ligger till grund för en klassificering av de lagerförda artiklarna. En artikelklass som stora delar av kapitalbindningsproblematiken kan hänföras till är artiklar med låg behovsfrekvens i kombination med leverantörernas minimala orderkvantiteter. För att minska detta problem rekommenderas ett fördjupat leverantörssamarbete i syfte att göra orderkvantiteterna mindre. För övriga artikelklasser föreslås en differentierad lagerstyrning som ett verktyg för att få kontroll över lagret. Kapitalbindningen i färdigvarulagret beror främst på att kunden, genom avtal, bestämmer hur deras ledtidskrav ska uppfyllas. Detta beslut bör istället fattas av Rimaster AB och baseras på kundorderpunktens placering. Det ojämna kapacitetsutnyttjandet beror bland annat på att produktionen är uppdelad i flera mindre grupper med kundfokus. Dessutom stämmer inte produktionsgrupperna överens med de grupper som använts planeringsmässigt. Av denna anledning föreslås ett nytt produktionsflöde där fyra produktorienterade slutmonteringsgrupper skapas, dessa bildar dessutom planeringsgrupper. Genom denna aggregering av resurser skapas förutsättningar för ett jämnare produktionsflöde och därmed även ett jämnare kapacitetsutnyttjande. Samtidigt föreslås ett nytt detaljplaneringssystem med funktionalitet enligt Workload Control-konceptet för att möjliggöra korta och säkra ledtider och en begränsad mängd produkter i arbete. En ytterligare bidragande orsak till det ojämna produktionsflödet är att produktionsbatcherna är stora, trots att ställtidsandelen normalt sett är låg. Detta beror på att batchstorleken normalt likställs med storleken på en kundorder. Följaktligen föreslås en minskning av batchstorlekarna vilket förutom att bidra till ett jämnare flöde även medför kortare produktionsledtider. / This Master Thesis has been carried out at Rimaster AB in Rimforsa, a sub-contractor in electronics and mechatronics. Rimaster AB has 140 employees and an approximate annual turnover of 116 MSEK. The main part of the production consists of manual work and is carried out on receipt of customer orders. The company perceives a fluctuating flow in the production and consequently fluctuations in the capacity utilization. Furthermore there is a considerable capital tye-up in the inventory of raw materials as well as in the inventory of finished goods. Therefore the purpose of this Master Thesis is to achieve levelled capacity utilization and less capital tied-up through an improved management of inventory and manufacturing. An inventory holding cost is calculated for the inventories respectively to determine the cost of capital tied-up. For the inventory of raw materials the cost is 15.8 percent of the annual average inventory value, and for the inventory of finished goods the cost is 16.9 percent. This yields an annual cost of 2.4 MSEK. Furthermore the inventory holding cost should be used in decisions regarding inventory management, e.g. when calculating order quantities. When analyzing the inventory of raw materials a number of types of stock items are identified. These types form the foundation of a classification of the stock items. A significant part of the capital tied-up relates to stock items with low demand combined with minimum order quantities from the suppliers. An improved co-operation with the suppliers in order to reduce these quantities is therefore recommended. For the remaining classes of stock items a differentiated inventory control system is proposed. In the inventory of finished goods the capital tied-up is mainly a consequence of customers requiring, by contract, how their demanded lead time shall be fulfilled. Instead this should be decided by Rimaster AB based on the position of the order penetration point. One reason to the fluctuating capacity utilization is that the production is divided into several sub-groups with customer focus. Furthermore these groups do not correspond to the groups used for production planning. A new production flow is therefore proposed with four product-oriented final assembly groups. These new groups should also be used for production planning. Through this aggregation of production resources it is possible to achieve a levelled production flow and hence a levelled capacity utilization. In combination with the measures mentioned above, a new production activity control system, in accordance to the Workload Control concept, is proposed. This control system enables short and safe lead times and a limited amount of work in progress. Another reason to the fluctuating capacity utilization, caused by a fluctuating production flow, is the use of large batches despite short set-up times. The size of a batch is normally equal to the size of a customer order. Consequently a reduction of the batch sizes is proposed in order to achieve a levelled production flow and shortened production lead times.

Recent developments in the area of Cyber-Physical Production Systems prove that high technology readiness level is already achieved and industrialization of such technologies is not far from today. Although these technologies seem to be convenient in providing solutions to environmental uncertainties, their application provides adaptability only at shop floor level. Needless to say, an enterprise cannot reach true adaptability without ensuring adaptation skills at every level in its hierarchy. Commonly used production planning and control approaches in industry today inherit from planning solutions which are developed in response to historical market characteristics. However, market tendency in recent years is towards making personalized products a norm. The emerging complexity out of this trend obliges planning systems to a transition from non-recurring, static planning into continuous re-planning and re-configuration of systems. Therefore, there is a need of responsive planning solutions which are integrated to highly adaptable production system characteristics. In this dissertation, Demand Responsive Planning, DRP, is presented which is a planning framework aiming to respond to planning needs of shifting trends in both production system technologies and market conditions. The DRP is based on three main constructs such as dynamicity, responsiveness and use of precise data. These features set up the foundation of accomplishing a high degree of adaptability in planning activities. By this means, problems from an extensive scope can be handled with a responsive behavior (i.e. frequent re-planning) by the use of precise data. The use of precise data implies to execute planning activities subject to actual demand information and real-time shop floor data. Within the context of the DRP, both a continuous workload control method and a dynamic capacity adjustment approach are developed. A test-bed is coded in order to simulate proposed method based on a system emulation reflecting the characteristics of cyber-physical production systems at shop floor level. Continuous Precise Workload Control, CPWLC, method is a novel approach aiming at precise control of workload levels with the use of direct load graphs. Supported by a multi-agent platform, it generates dynamic non-periodic release decisions exploiting real time shop floor information. As a result, improved shop floor performances are achieved through controlling workload levels precisely by the release of appropriate job types at the right time. Presented dynamic capacity adjustment approach utilizes rapid re-configuration capability of cyber-physical systems in achieving more frequent capacity adjustments. Its implementation architecture is integrated to the CPWLC structure. By this means, a holistic approach is realized whereby improved due date performance is accomplished with minimized shop floor congestion. Hence, sensitivity to changing demand patterns and urgent job completions is improved. / <p>QC 20150907</p>

Submitted by Aelson Maciera (aelsoncm@terra.com.br) on 2017-10-10T13:29:21Z No. of bitstreams: 1 DissTKK.pdf: 6363757 bytes, checksum: c18f1887d457c1920bc3a2ff568e2f25 (MD5) / Approved for entry into archive by Ronildo Prado (producaointelectual.bco@ufscar.br) on 2017-10-10T17:27:10Z (GMT) No. of bitstreams: 1 DissTKK.pdf: 6363757 bytes, checksum: c18f1887d457c1920bc3a2ff568e2f25 (MD5) / Approved for entry into archive by Ronildo Prado (producaointelectual.bco@ufscar.br) on 2017-10-10T17:27:20Z (GMT) No. of bitstreams: 1 DissTKK.pdf: 6363757 bytes, checksum: c18f1887d457c1920bc3a2ff568e2f25 (MD5) / Made available in DSpace on 2017-10-10T17:31:49Z (GMT). No. of bitstreams: 1 DissTKK.pdf: 6363757 bytes, checksum: c18f1887d457c1920bc3a2ff568e2f25 (MD5) Previous issue date: 2015-06-08 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / The improvement in the delivery reliability performance in Make-To-Order (MTO) companies has been becoming an important competitive criterion in the recent market context. Thus, it gets clear the importance of researches able to present tools to help the identification of enhancement opportunities in the matter of delivery reliability. The identification of opportunities requires a structure of diagnosis of the recent situation. However, depending on the performance problem to be diagnosed, a theoretical understructure based on specific scientific knowledge is needed. This work presents the framework developed by Soepenberg et al. (2012c) based on Workload Control (WLC) concepts. Such framework is composed by a structure for the diagnosis process of the reliability performance that allows browsing from the obtained performance to the subjacent causes related to Production Planning and Control (PPC). The aim of the present work is to present the WLC as well as the diagnostic tools with the purpose of elucidating their applicability through the framework developed by Soepenberg et al. (2012c) in a real context through a case study. The results of the case study indicated that the framework is a key instrument for diagnosis due to the accuracy by which it defines the causes of delays of the orders related to the PPC decisions. The application of the framework indicated that the lack of spare parts is the most impacting factor on delays, however this is not a cause only related to the company PPC decisions, but to external factors that are out of the company’s reach. Another result obtained is the verification that most of the orders are concluded before the date set. This is due to the lack of accuracy in the definition of the delivery dates and to the estimative mistakes of the capacity to be used for the maintenance of each part number, whose responsibilities rely on PPC. / A melhoria no desempenho da confiabilidade de entrega em empresas Make-To-Order (MTO) vem se tornando um importante critério competitivo na atual conjuntura de mercado. Diante do exposto, fica evidente a importância de pesquisas que apresentem ferramentas para o auxílio na identificação de oportunidades de melhorias no que se refere à confiabilidade de entrega. A identificação de oportunidades de melhorias requer uma estrutura de diagnóstico do desempenho da situação atual. No entanto, dependendo do problema de desempenho a ser diagnosticado, um arcabouço teórico com base no domínio de conhecimentos específicos da científica é necessário. Este trabalho apresenta o framework desenvolvido por Soepenberg et al. (2012c), que se baseia nos conceitos de WLC. Tal framework consiste em uma estrutura para o processo de diagnóstico do desempenho da confiabilidade de entrega, que permite navegar a partir do desempenho alcançado para as causas subjacentes relacionadas ao PCP. O objetivo do presente trabalho é apresentar o WLC, bem como as ferramentas de diagnóstico com o propósito de elucidar suas aplicabilidades através do framework desenvolvido por Soepenberg et al. (2012c) em um contexto real através de um estudo de caso. Os resultados do estudo de caso apontaram que o framework é um importante instrumento de diagnóstico devido à precisão para a determinação das causas de atraso das ordens relacionadas às decisões de PCP. A aplicação do framework identificou que a falta de peças é o fator mais impactante nos atrasos, porém a mesma não é uma causa relacionada somente as decisões de PCP da empresa, mas a fatores externos que não podem ser controlados pela empresa. Outro resultado obtido é a constatação de que a maioria das ordens é concluída antes das datas estabelecidas. Esse fato é resultado da falta de acurácia na determinação das datas de entrega e do erro na estimativa da capacidade a ser utilizada para a manutenção de cada part number, cuja responsabilidade dessas atividades é do PCP.

Workload control (WLC) systems constitute a framework mainly for the inputoutput control systems which regulate both jobs&rsquo / queues into the workshop and the flow of finished goods out of the workshop. This study is concerned with the job entry and release level of WLC which maintains a pool of unreleased jobs for the controlled release of jobs. While most of the studies in WLC concepts deal with the centralized workload control, our study decentralizes the job entry and release control and makes workstations more powerful in schedule decision making. Job&rsquo / s information is sent to the workstations by mediator which is the supervisor of the workstation. Both mediator and work stations are represented by agents in a distributed system. Jobs&rsquo / routing information is assumed to be known in advance. The developed system is verified and validated by means of test runs. Results are analyzed as well.