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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Optimierungspotenziale in der petrochemischen Industrie

Treitl, Stefan, Hilber, Jakob, Jammernegg, Werner January 2017 (has links) (PDF)
Die Prozesse und Aktivitäten der petrochemischen Industrie bieten aufgrund ihrer Vielfalt und Komplexität meist ein großes Potenzial für Verbesserungen. In diesem Beitrag sollen anhand kurzer Fallbeispiele, die in Kooperation mit OMV entstanden sind, drei solcher Optimierungspotenziale beispielhaft aufgezeigt werden. Dabei wird der Fokus auf die Downstream-Logistik gelegt und die Distribution der raffinierten Endprodukte zu den Endkunden (Tankstellen) analysiert. Auf strategischer Planungsebene werden die optimalen Standorte von Tanklägem bestimmt und die ökonomische und ökologische Performance verschiedener Netzwerk-Designs verglichen. In einem Fallbeispiel zur taktischen Planung wird ein Optimierungsmodell zur Planung der Transportmengen in einem Distributionsnetzwerk mit stochastischer Nachfrage dargestellt. Die effiziente Tourenplanung von den Lkw zu den Tankstellen stellt schlussendlich ein operatives Planungsbeispiel dar.
2

The Complexity of Safety Stock Placement in General-Network Supply Chains

Lesnaia, Ekaterina, Vasilescu, Iuliu, Graves, Stephen C. 01 1900 (has links)
We consider the optimization problem of safety stock placement in a supply chain, as formulated in [1]. We prove that this problem is NP-Hard for supply chains modeled as general acyclic networks. Thus, we do not expect to find a polynomial-time algorithm for safety stock placement for a general-network supply chain. / Singapore-MIT Alliance (SMA)
3

RealTime and Anytime Supply Chain Planning

Schmalzried, Dirk 12 March 2012 (has links) (PDF)
Bisher sind die Planungsebenen des Supply Chain Management (SCM) konzeptionell, personell und softwaretechnologisch getrennt und oft hierarchisch organisiert. Geschäftsprozesse definieren die Übergänge von und Rückkopplung zwischen Ebenen grober, strategisch/ taktischer Planung und Ebenen feiner, operationaler Planung. Diese Trennung führt zu konzeptionellen, prozessualen und temporalen sowie zu systemtechnischen Defiziten im Supply Chain Planning (SCP). Kerngedanken des neuen Konzepts sind, alle heute üblichen Planungsebenen vollständig auf das operative Modell zu gründen die neuen Softwaresysteme vollständig im RAM zu verankern sowie mit neuen Nutzeroberflächen auszustatten, die den Aspekt der virtuellen Aggregation und Disaggregation der Daten zur Laufzeit befördern. Durch die Ergebnisse der Arbeit wird das den Stand der Technik darstellende Paradigma der sequenziellen, hierarchischen Planung verändert zu einem Konzept einer jederzeit ausführbaren (Anytime) Planung, welche Planungsergebnisse innerhalb sehr kurzer Antwortzeiten (Real-Time) liefert. Durch die schnellen Antworten können zudem ganz neue interaktive, simulationsbasierte Planungsprozesse anstelle bisheriger batchorientierter Prozesse eingeführt werden. Es werden Vorteile gegenüber dem alten Konzept und die praktische Machbarkeit anhand von Softwarefallstudien bewertet.
4

RealTime and Anytime Supply Chain Planning

Schmalzried, Dirk January 2011 (has links)
Bisher sind die Planungsebenen des Supply Chain Management (SCM) konzeptionell, personell und softwaretechnologisch getrennt und oft hierarchisch organisiert. Geschäftsprozesse definieren die Übergänge von und Rückkopplung zwischen Ebenen grober, strategisch/ taktischer Planung und Ebenen feiner, operationaler Planung. Diese Trennung führt zu konzeptionellen, prozessualen und temporalen sowie zu systemtechnischen Defiziten im Supply Chain Planning (SCP). Kerngedanken des neuen Konzepts sind, alle heute üblichen Planungsebenen vollständig auf das operative Modell zu gründen die neuen Softwaresysteme vollständig im RAM zu verankern sowie mit neuen Nutzeroberflächen auszustatten, die den Aspekt der virtuellen Aggregation und Disaggregation der Daten zur Laufzeit befördern. Durch die Ergebnisse der Arbeit wird das den Stand der Technik darstellende Paradigma der sequenziellen, hierarchischen Planung verändert zu einem Konzept einer jederzeit ausführbaren (Anytime) Planung, welche Planungsergebnisse innerhalb sehr kurzer Antwortzeiten (Real-Time) liefert. Durch die schnellen Antworten können zudem ganz neue interaktive, simulationsbasierte Planungsprozesse anstelle bisheriger batchorientierter Prozesse eingeführt werden. Es werden Vorteile gegenüber dem alten Konzept und die praktische Machbarkeit anhand von Softwarefallstudien bewertet.
5

A Base Stock Inventory Model for a Remanufacturable Product

Graves, Stephen C. 01 1900 (has links)
We report on an industrial project in which we developed an inventory model to provide decision support for the design and deployment of the field service support system for a remanufacturable product. The product was a dialysis unit for home use. Each unit that was installed in a home would eventually be removed due to failure, or the need for preventative maintenance, or the termination of the service. Upon removal, each unit was shipped to a central depot for re-manufacturing so that it could be returned to service. We develop a model to determine the inventory requirements at each regional depot, and then describe how to use the model to determine the inventory requirements in the two-echelon system consisting of the central facility and the regional depots. / Singapore-MIT Alliance (SMA)
6

Integrated Modelling for Supply Chain Planning and Multi-Echelon Safety Stock Optimization in Manufacturing Systems

Alfaify, Abdullah Yahia M. 12 March 2014 (has links)
Optimizing supply chain is the most successful key for manufacturing systems to be competitive. Supply chain (SC) has gotten intensive research works at all levels: strategic, tactical, and operational levels. These levels, in some researches, have integrated with each other or integrated with other planning issues such as inventory. Optimizing inventory location and level of safety stock at all supply chain partners is essential in high competitive markets to manage uncertain demand and service level. Many works have been developed to optimize the location of safety stock along supply chain, which is important for fast response to fluctuation in demand. However, most of these studies focus on the design stage of a supply chain. Because demand at different horizon times may vary according to different reasons such as the entry of different competitors on market or seasonal demand, safety stock should be optimized accordingly. At the planning (tactical) level, safety stock can be controlled according to each planning horizon to satisfy customer demand at lower cost instead of being fixed by a decision taken at the strategic level. On the other hand, most studies that consider safety stock optimization are tied to a specific system structure such as serial, assembly, or distribution structure. This research focuses on formulating two different models. First, a multi- echelon safety stock optimization (MESSO) model for general supply chain topology is formulated. Then, it is converted into a robust form (RMESSO) which considers all possible fluctuation in demand and gives a solution that is valid under any circumstances. Second, the safety stock optimization model is integrated with tactical supply chain planning (SCP) for manufacturing systems. The integrated model is a multi-objective mixed integer non-linear programming (MINLP) model. This model aims to minimize the total cost and total time. A case study for each model is provided and the numerical results are analyzed.
7

Integrated Modelling for Supply Chain Planning and Multi-Echelon Safety Stock Optimization in Manufacturing Systems

Alfaify, Abdullah Yahia M. January 2014 (has links)
Optimizing supply chain is the most successful key for manufacturing systems to be competitive. Supply chain (SC) has gotten intensive research works at all levels: strategic, tactical, and operational levels. These levels, in some researches, have integrated with each other or integrated with other planning issues such as inventory. Optimizing inventory location and level of safety stock at all supply chain partners is essential in high competitive markets to manage uncertain demand and service level. Many works have been developed to optimize the location of safety stock along supply chain, which is important for fast response to fluctuation in demand. However, most of these studies focus on the design stage of a supply chain. Because demand at different horizon times may vary according to different reasons such as the entry of different competitors on market or seasonal demand, safety stock should be optimized accordingly. At the planning (tactical) level, safety stock can be controlled according to each planning horizon to satisfy customer demand at lower cost instead of being fixed by a decision taken at the strategic level. On the other hand, most studies that consider safety stock optimization are tied to a specific system structure such as serial, assembly, or distribution structure. This research focuses on formulating two different models. First, a multi- echelon safety stock optimization (MESSO) model for general supply chain topology is formulated. Then, it is converted into a robust form (RMESSO) which considers all possible fluctuation in demand and gives a solution that is valid under any circumstances. Second, the safety stock optimization model is integrated with tactical supply chain planning (SCP) for manufacturing systems. The integrated model is a multi-objective mixed integer non-linear programming (MINLP) model. This model aims to minimize the total cost and total time. A case study for each model is provided and the numerical results are analyzed.
8

Advanced supply chain planning processes and decision support systems for large-scale petrochemical companies

Louw, Johannes Jacobus 12 1900 (has links)
Thesis (PhD (Logistics))--University of Stellenbosch, 2006. / Conventional supply chain integration concepts focus primarily on the internal and external integration of individual supply chains (can be viewed as intra-supply chain integration). Due to the highly integrated nature of petrochemical value chains, related supply chains should also be integrated by taking account of enterprise/industry-wide synergies and interdependencies (can be viewed as inter-supply chain integration). Inter-supply chain integration can typically develop along three dimensions: - Upstream feed clusters (upstream in the chemical value chain) - Downstream product clusters (downstream in the chemical value chain) - Macro logistics network clusters (within and across related logistics networks for liquid bulk, dry bulk, packaged goods and gases) This dissertation presents a generic framework of applicable intra- and inter-supply chain planning processes that supports related long- (strategic), medium- (tactical) and short-term (operational) supply chain decisions for large-scale petrochemical companies. This type of companies has to manage relative complex supply chains. Highly complex supply chains (due to an extensive product portfolio, supplier base, customer base, manufacturing processes, transportation, and management processes and systems) require far more advanced planning processes than simple supply chains. Advanced supply chain planning processes cover an extended supply chain scope, deal with longer time horizons, and utilize more sophisticated analytical techniques and decision support systems. An extensive literature study, supplemented by empirical research in the South African petrochemical industry, provided the foundation for the advanced supply chain planning framework concluded in this dissertation. Semi-structured interviews and a questionnaire presented to an informed audience constitute the empirical research conducted. The related best practices, concepts, approaches followed, and level of advancement in three supply chain planning dimensions were derived. To guide petrochemical companies along the planning advancement journey, the roadmap developed can be utilized for the application and implementation of the advanced supply chain planning framework. This roadmap articulates the advancement stages, dimensions, characteristics, and triggers to advance. Typical characteristics associated with the advancement stages and dimensions provide the means for a company to assess their level of progression. The essential mechanisms that can enable interventions are also articulated.
9

Hantering av informations- och materialflöden för att främja logistiken på anläggningsprojekt / Management of information and material flow to promote logistics within construction projects

Lennéer, Rebecca, Lever, Nina January 2021 (has links)
Syfte: I problembeskrivningen konstaterades att de logistikproblem som upplevs på byggprojekt ofta är kopplade till glappet mellan projekterings- och produktionsfasen. Problemen är även kopplade till brist på informationsutbyte, projektförståelse och långvariga relationer samt attityd till samarbeten och skilda tolkningar. Syftet är att undersöka hur informations- och materialflödena hanteras på anläggningsprojekt samt vad som kan göras för att optimera försörjningskedjan och därmed främja logistiken.  Metod: Undersökningens huvudsakliga angreppssätt är en kvalitativ studie. Kvalitativa data, i form av primärdata, samlas in genom en intervjustudie. För att få en teoretisk bakgrundsförståelse samlas sekundärdata in genom att studera tidigare litteratur inom ämnet. Detta ligger till grund för att uppnå det formulerade målet för undersökningen.  Resultat: Studien konstaterar att ett gränsöverskridande samarbete och ett helhetsperspektiv behövs för att gynna försörjningskedjan och logistikarbetet på ett anläggningsprojekt. Om aktörer i de olika faserna involveras i varandras arbete skapas bättre förutsättningar för att hantera informations- och materialflödena och därmed främja logistiken på projektet. Resultatet bidrar till ökad inblick i hur flödena hanteras idag samt vilka begränsningar och förbättringsmöjligheter som finns. Detta ger en indikation på varför anläggningsbranschen inte har nått samma framgångar kring förbättring av försörjningskedjan som andra företag.  Konsekvenser: För att möta den utmaning som finns i anläggningsbranschen med avseende på logistiken krävs följande:  Att informations- och materialflödet hanteras på ett strukturerat sätt. Att skapa långvariga relationer, använda digitala verktyg i större omfattning och att entreprenörerna gör integrerade inköp. Att aktörer inom de olika faserna integreras i varandras arbete, ha en samordningsansvarig inom projektet och använda sig utav logistikcentra.  Begränsningar: Studien avgränsades till att fokusera på aktörer som i regel inte har en direkt inverkan på logistikarbetet. I efterhand görs bedömningen att det varit till rapportens fördel att intervjua fler aktörer som kan påverka logistiken. Detta för att få en bredare bild av den syn som finns i projekterings- och planeringsfasen samt byggfasen. Trots att studien visar på olika aktörers perspektiv av situationen uppnås inte en rättvis bild och ett mer balanserat urval av respondenter hade behövts. Det är viktigt att nämna att studien inte fokuserar på att undersöka hur förbättringarna kan genomföras.  Nyckelord: Logistik, Supply Chain Management, ramverk för Supply Chain Planning, anläggningsprojekt, informations- och materialflöden. / Purpose: In the introduction it was concluded that the experienced logistical difficulties on a construction site often were related to multiple reasons. Examples of these are the disconnection between the design and production phase, lack of information exchange, project understanding and relationships as well as attitude towards cooperation and the various interpretations. The aim of this study is to investigate how information and material flows are managed within construction projects as well as finding options to optimize the supply chain and in turn promote the logistics.  Method: For the methodological approach of the study, a qualitative method is used. Qualitative data, in form of primary data, is collected through an interview study. To build an understanding of the theoretical background, secondary data is gathered by studying former literature research findings. This is the basis for achieving the goal of the study.  Findings: The result of the study shows that a cooperation between disciplines and a holistic approach is needed to promote the supply chain and logistics within a construction project. When disciplines in the various phases are involved in each other’s work, conditions are being created for managing the information and material flows and in turn improving the logistics. The result contributes to insight as to how the flows are managed today as well as the experienced limitations and improvements. This gives an indication of why the construction industry has not achieved the same success in enhancement of the supply chain as other industries.  Implications: This is what is needed to meet the challenge of improving the logistics in the construction industry:  Information and material flows need to be handled in a structured manner.  Creation of long-term relationships, increased usage of IT-tools and integrating purchases within contractors.  Disciplines within the various phases need to be integrated in each other’s work, having someone who coordinates the responsibilities within the project and utilization of logistics centers.  Limitations: Initially, the study was limited to only focusing on disciplines who generally do not have a direct impact on the logistics. In hindsight, it is considered that the study would benefit from interviewing more disciplines who can affect the logistics. This would provide a broader view of the aforementioned phases’ perspective. Although the study indicates different disciplines’ standpoint of the situation, a fair result is not fulfilled as a more equal selection of interviewees would be needed. It is important to note that the study does not focus on investigating how the improvements can be implemented.  Keywords: Logistics, Supply Chain Management, framework for Supply Chain Planning, construction projects, information and material flow.
10

Supply chain planning : processes of a sports retail company

Terblanche, Lee-Anne 03 1900 (has links)
Thesis (MComm)--Stellenbosch University, 2015. / ENGLISH ABSTRACT: There are numerous supply chain planning processes and activities that need to take place to ensure efficiency and effectiveness in a company. For the case study retailer, these planning processes and activities contribute to the end goals and objectives of the company. In order to reach these goals and objectives, the importance and contribution of each of the planning processes and activities must be determined. Supply chain planning can provide a company with a competitive advantage, but it can also lead to catastrophic events when it is not fully utilised or poorly executed. A case study was done on a South African sports retailer to determine to what extent the different supply chain planning processes and activities contribute to the end goals and objectives of this retailer and how these goals and objectives are tracked within the company. The implementation of planning processes and -activities were also investigated and what the consequences may be when the planning processes and activities are poorly executed. Goals and objectives which were given to the retailer‟s planners were investigated and thoroughly studied. Some of these goals included achieving effective stock policies, managing gross sales margins for products and accurate forecasting. A hybrid research method was used to gather both qualitative and quantitative data. Interviews were conducted with planners in the company to explore their current planning methods as well as to highlight the shortcomings thereof. A job satisfaction questionnaire determined the motivators and hygiene factors (where hygiene factors refer to factors such as the employee‟s relationships with their supervisor, salaries and working conditions) of the employees in the company. A low level of motivators and hygiene factors may contribute to employee‟s responses at the workplace: exit, voice, loyalty and neglect. The importance of supply chain planning in the sports retail industry and the shortcomings this retailer has on supply chain planning methods were determined and the crucial role planning plays in this retailer was effectively determined and comprehended. Areas for improvement include, realistic budgeting and planning, enhanced forecasting methods and investing in employee training. Results also show that the retailer is managing effective levels of planning to reach the goals and objectives of the company. However, there are key areas for improvement where focus should be placed upon. / AFRIKAANSE OPSOMMING: Daar is talle beplanningsprosesse en beplanningsaktiwiteite wat moet plaasvind om die effektiwiteit en doeltreffendheid van n maatskappy te verseker. Vir die kleinhandelaar in die gevallestudie dra hierdie beplanningsaktiwiteite, en -prosesse by tot die doelwitte en doelstellings van die maatskappy. Om hierdie doelwitte en doelstellings te kan bereik, moet die belangrikheid en bydrae van die beplanningsprosesse en beplanningsaktiwiteite bepaal en ten volle begryp word. Voorsieningskettingbeplanning kan aan „n maatskappy „n mededingende voordeel verskaf, maar kan ook lei tot katastrofiese gebeure indien die voosieningskettingbeplanning swak uitgevoer word of nie ten volle aangewend word nie. „n Gevallestudie is gedoen op „n Suid-Afrikaanse kleinhandelaar in sporttoerusting om te bepaal watter tipe beplanningsprosesse en beplanningsaktiwiteite plaasvind in hierdie landswye kleinhandelaar. Die implementering van die beplanningsprosesse en beplanningsaktiwiteite is ook ondersoek en wat die nagevolge kan wees wanneer hierdie beplanningsprosesse en beplanningsaktiwiteite swak uitgevoer word. Doelwitte en doelstellings wat aan die beplanners van die besigheid deurgegee word, is deeglik bestudeer. Sommige van hierdie doelwitte sluit in die bereiking van effektiewe voorraadbeleide, handhawing van bruto verkope marges vir produkte en akkurate vooruitskattings. „n Hibriede navorsingsmetode is gebruik vir die insameling van kwalitatiewe en kwantitatiewe data. Onderhoude is met die beplanners van die maatskappy gevoer om die huidige beplanningsmetodes te verken en om die tekortkomings in die beplanningsmetodes uit te wys. „n Werkstevredenheid vraelys het die motiveerders en higiëne faktore (waar higiëne faktore verwys na werknemers se verhouding met die toesighouer, salarisse en werksomstandighede) van die werknemers bepaal. Lae vlakke van motiveerders en higiëne faktore kan lei tot die volgende reaksies: ontrekking, stem, lojaliteit en verwaarlosing. Die kritieke belangrikheid wat beplanningsprosesse en beplanningsaktiwiteite behels vir hierdie kleinhandelaar was vasgestel, asook die tekortkominge wat hierdie kleinhandelaar met voorsieningskettingbeplanningsmetodes het. Verbeteringsareas sluit in, realistiese beplanning en „n realistiese begroting, verbeterde vooruitskattingsmetodes en om in die werknemer se opleiding te investeer. Dit is bepaal dat hierdie kleinhandelaar handaaf effektiewe vlakke van beplanning om einddoelstellings en einddoelwitte te bereik. Daar is egter, sekere areas, waar fokus op geplaas moet word. Sleutelwoorde: Voorsieningskettingbeplanning, beplanningsprosesse, beplanningsaktiwiteite.

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