[Truncated abstract] Currently, one of the active areas of research in computer graphics is related to creating realistic images and animations that mimic the world we see around us. There has been significant work in modeling and simulating natural phenomena such as fire, clouds, water, and vegetation. Some of these works are employed in the entertainment industry, especially as special effects in cinematic films. Of particular interest is the area of vegetation, given the possible structural complexity and variation in different types of plants. This provides a challenge to develop methods and techniques that effectively and realistically model the movement and behavior of plants. In response to this challenge, there has been significant work in the area of modeling plant structure, as well as modeling of the dynamics and wind interaction of tree branches. However, there is a distinct lack of approaches involved with modeling the dynamics and behavior of individual leaves. Most of the previous approaches focus on the modeling of the branches of a tree, and rarely consider the movement of the leaves in detail. This makes it particularly hard to model the interactions of plants with relatively large leaves, where the dynamics of the leaves are important. In other words, there is no method that could effectively simulate the lower canopy of a forest or jungle, where there are many ferns, saplings, and other broad-leafed plants. Therefore, I present in this thesis a leaf animation system that is designed specifically for simulating and animating plants with relatively large leaves with realistic dynamics in real-time. .... These interactions illustrate the flexibility and robustness of the leaf movement model. In particular, I present a novel approach in modeling volumetric wind through the wind cube that approximates wind behavior such as obstruction by leaves, and constructive and destructive interference. This unique approach is based on modeling wind as a spatial collection of wind vectors and the interaction of the vectors is governed by the rules of each cube-shaped cell of the wind cube. In the end, this wind cube allows for convincing behavior of wind and the subsequent interaction with the leaves of a plant. The leaf animation system is also suitable for simulating a number of plants in a landscape. This is possible through another novel method of reducing the rendering time to allow for more plants to be simulated. This method involves using an animated texture in place of plants that are far from the camera, when the difference visually is not blatantly noticeable. This is a form of the commonly used levels of detail to reduce the complexity of the landscape, but my method is novel in that it has not been implemented in a way where the texture itself is animated in place of the plant. I investigate the strengths and limitations of this approach in reducing rendering time for a landscape of plants. Thus, the leaf animation system is suitable for realistic and interactive virtual reality environments. These virtual environments feature heavily in current video games that involve realistic and believable worlds. In addition to the film and video game industry, these virtual environments are also integral in the application of virtual reality as psychological therapies.

This thesis work in automation technology at 30 credits is conducted at Volvo Cars Cooperation (VCC) in collaboration with the University of Skövde. With the current staffing method VCC are experiencing difficulties achieving an optimal utilization of operators as there has been difficult to ascertain how much work an operator can handle. Operators are an often overlooked part of simulation studies because they are complex to model. The completed thesis consists of developing a standardized operator object in the simulation software Plant Simulation, developed by Siemens. Using this object, it will be easier to staff optimally with respect to the number of work areas, operator skills and how many operators that are required for the given work areas. The existing VCC Plant Simulation library already has an object for operators. This operator object was used as the basis for the development of the new operator object. When developing the new object, data collection was made in form of both qualitative and quantitative data to find out what functionality the new object needed. The existing object was evaluated against the functionality requirements to determine what were needed to be added, removed or modified. Five main areas were considered important to develop: (1) operators that can work across two or more work areas, (2) walking time for operators, (3) learning effect, (4) the learning curve for operators and (5) operators who work on different shifts. The learning curve was only partly developed, but the other four areas were fully implemented. In order to test and analyze the object, three experiments were carried out using different case studies, where one of these cases studies was a real production line. The experimental design was jointly created with the VCC reference group and the University of Skövde. The main objectives of the experiments were to reduce the number of operators and increase throughput per hour. The result of the optimisation of the real production line showed that a significantly smaller staffing could be achieved without a major effect on the throughput. The results of the project were that a standardized operator object was developed according to the specifications and objectives set for the project. This object provides the ability to quickly and easily implement operators in a simulation model. To verify the applicability of the operator object, it was successfully imported and used for simulation-based optimisation in three different simulation models. The operator object also contains functionalities that provide more realistic operators, such as the walk time to the operations, operators that can work across several work areas and competence for operators as well as learning. The results of this project involve a simpler implementation of more realistic operators and thus lead to more realistic simulation models. / Examensarbetet inom automatiseringsteknik på 30hp är genomfört vid Volvo Cars Coperation (VCC) i Skövde i samarbete med Högskolan i Skövde.  Med dagens bemanningsmetod upplever VCC svårigheter med att uppnå en optimal beläggning på operatörerna, då det har varit problematiskt att få fram hur mycket arbete en operatör klarar av. Operatörer är en ofta förbisedd del av simulering eftersom de är komplexa att modellera. Det genomförda examensarbetet består av att utveckla ett standardiserat operatörsobjekt i simuleringsmjukvaran Plant Simulation från Siemens. Med hjälp av detta objekt ska det bli enklare att bemanna effektivt med avseende på antal arbetsområden, operatörernas kompetens samt hur många operatörer det krävs per arbetsområde. I VCCs egenutvecklade bibliotek i Plant Simulation fanns det redan ett objekt för operatörer. Detta objekt användes som grund för utveckling av det nya operatörsobjektet. Vid utveckling av det nya objektet utfördes datainsamling i form av både kvalitativ och kvantitativ art för att ta reda på vilken funktionalitet som det nya objektet skulle inneha. Det existerande objektet utvärderades mot dessa funktionalitetskrav för att bestämma vad som skulle läggas till, tas bort eller ändras. Fem stycken huvudområden ansågs vara viktiga att utveckla: (1) operatörer som kan arbeta över två eller flera arbetsområden, (2) gångtid för operatörer från och till operationer, (3) kompetens för operatörerna, (4) inlärningskurva för operatörerna och (5) operatörer som jobbar på olika skift. Av dessa implementerades alla utan inlärningskurvan fullt ut, inlärningskurvan är en del av det fortsatta arbetet. För att kunna testa och analysera objektet genomfördes tre stycken experiment i form av fallstudier varav en av dessa fallstudier var av en verklig produktionslinje. Experimentplanen togs fram gemensamt med VCC referensgrupp och Högskolan i Skövde. Huvudmålen med experimenten var att minska antalet operatörer och att öka takt per timma. Resultatet av optimeringen för den verkliga produktionslinjen visade att en signifikant mindre bemanning skulle kunna uppnås utan en större effekt på takt per timma. Resultatet av projektet var ett standardiserat operatörsobjekt som togs fram enligt de specifikationer och mål som definierats för projektet. Detta objekt ger möjligheten att snabbare och enklare implementera operatörer i en simuleringsmodell. För att verifiera användbarheten av operatörsobjektet, importerades det och användes för simulering-baserad optimering i tre olika simuleringsmodeller. Operatörsobjektet innehåller också funktionaliteter som ger mer realistiska operatörer så som gångtid till operationer, operatörer som kan arbeta över flera arbetsområden, kompetens för operatörer samt inlärning. Resultatet från detta projekt innebär en enklare implementering av operatörer i en simuleringsmjukvara och bidrar således till mer realistiska simuleringsmodeller.

Goal of this diploma thesis is to create discrete simulation model of a buffer for sorting cars by their color in order to create bigger color blocks in front of upper paint area in paintshop of ŠKODA AUTO a.s. in Mladá Boleslav. Simulation model is created in Plant Simulation software produced by Siemens PLM Software company. Section of this diploma thesis is paid to system analysis of conveyors used in solved area and to suggestion of planned modifications. It is tested by simulation model whether the planned modifications would have positive effect on production characteristic in concern area. Conclusions are deduced from mentioned experiments.

This diploma thesis is based on creation of a simulation model of paint shop in the company ŠKODA AUTO a.s. The model was created in the simulation software Tecnomatix Plant Simulation. It is tested by simulation model whether the planned modifications in a buffer for sorting cars by their color would have positive effect on Perlenkette principle. The Perlenkette principle will help to stabilize supplier processes and reduction of running production times. Conclusions are deduced from carried out simulation experiments.

Volvo GTO Powertrain i Köping står inför införande av tre nya produktvarianter som ska ersätta befintliga produktvarianter. I dagsläget monteras produkterna som ska ersättas av de nya produktvarianterna i tre separata flöden. Införandet av de nya produktvarianterna medför att två av produktvarianterna ska tillverkas i samma monteringsflöde. Syftet med examensarbetet är att ta fram förslag på monteringsflöden som har flexibiliteten att producera två av de nya produktvarianterna i samma monteringsflöde med tillhörande provkörning. Monteringsflödet ska även klara av en säsongsberoende efterfrågan mellan 23 - 40 st produkter per skift, med en differens på ± 2,5 %. För att korrigera antalet som ska produceras beroende på säsong ska ske genom att korrigera antalet montörer i monteringsflödet och antalet operatörer i provkörningen. För att skapa en förståelse över de befintliga monteringsflödena har en nulägesanalys av monteringsflödena som ska slås ihop till ett flöde genomförts. Datainsamlingen i nulägesanalysen har genomförts genom intervjuer av produktionsteknisk personal, samt genom studerande av AviX analyserna på de befintliga monteringsflödena. Nulägesanalysen har varit till grund för att skapa en förståelse över hur monteringen fungerar i dagsläget.   Volvo har även tagit fram ett förslag på hur dom vill att det framtida monteringsflödet ska se ut. Volvos förslag har varit till grund för att skapa en förståelse över det tänkta framtida monteringsflödet med tillhörande provkörning. För att uppnå syftet med arbetet har två simuleringsmodeller skapats för att testa systemet under olika scenarier för att klara av den varierande efterfrågan. Den ena simuleringsmodellen använder sig av Volvos förslag på det framtida systemet och den andra modellen har genom experiment korrigerat cykeltiderna i provkörningen, arbetstempon i monteringsflödet har ombalanserats och tillgänglighet i provkörningen har ökats. Resultaten från experimenten är att simuleringsmodellen med korrigerade cykeltider, ombalanserad och ökad tillgänglighet klarar av den varierande efterfrågan på 40 produkter per skift. Det krävdes dock relativt stora korrigeringar från Volvos förslag för att uppnå önskad efterfrågan. För att avgöra antalet montörer och operatörer som krävs beroende på antalet efterfrågade produkter skapades en bemanningstabell. / Volvo GTO Powertrain is facing the introduction of three new product types of products which shall replace existing product types. In the current situation are the products, which shall be replace by new product types, assembled in three separate flows. The introduction of the new product types includes that two product types are being assembled in the same assembly flow. The purpose of this report is to make suggestions on assembly flows that have the flexibility to produces two of the new product types in the same assembly flow with associated trial area. The assembly flow shall also accomplish the customer’s demand depending on season with 23 - 40 products per shift, with a difference of ± 2,5 %. To adjust the quantity that shall be produced depending on season shall be done by adjusting the quantity of fitters in the assembly flow and the quantity of operators in the trial area. To create an understanding of the existing assembly flows has an analysis of the present situation, of the assembly flows which shall be combined into one assembly flow, been completed. The data collection in the analysis of the present situation has been completed through interviews with production engineers staff, also by studying the AviX analysis concerning the existing assembly flows. The analysis of the present situation has been founded to create an understanding of how the assembly works today. Furthermore, Volvo has developed a proposal on how the future assembly flow shall look like. Volvo’s proposal has been founded to create an understanding of the future assembly flow with associated trial area. To achieve the purpose of this work has two simulation models been created to test the system under different scenarios to manage the varying demand. One of the simulation models is using Volvo’s proposal on the future system and the other model has adjusted cycle times in the trial area through experiments, the work pace in the assembly flow has been rebalanced and the OEE in the trial run has been increased. The results from the experiments are that the simulation model with adjusted cycle times, rebalanced and increased OEE is capable of coping with the varying demand on 23 – 40 products per shift. However, relatively large adjustments were required from Volvo’s proposal to achieve the desired demand. A table of staffing was created to determine how many fitters and operators were required depending on the quantity of demanded products.

VSM, Value stream mapping, V2SM, virtual value stream mapping, lean, lean manufacturing, DES, discrete event simulation, Tecnomatix Plant Simulation

The aim of the diploma thesis is to create a simulation model of the logistic chain of the inter-object transport of material, in order to verify the set requirements, which are require on the logistic chain. The simulation model is created in Plant Simulation software produced by Siemens PLM Software company. Section of this diploma thesis is the analysis of the solved area, the simulation experiments on the simulation model and suggestion for improvement the current state of the logistic chain.

This thesis is focused on using discrete event simulation in a large plant in order to improve the control logic of the production department. Specifically it’s about the factory ŠKODA AUTO a.s. located in Mladá Boleslav and solved production node is the paint shop area. The chapters of this thesis are focused on used conveyor technology, basics of discrete event simulation, the subsequent development of a virtual model, design of simulation experiments and concept of a new solution. At the end of this work evaluation of proposed solution with comparison to the original solution is included.

The aim of the diploma thesis is to design of a new concept of material handling from the automatic warehouse to the manufacturing area and comparison with the original concept using computer simulation. The simulation model is created in Plant Simulation software from PLM Software. Part of the thesis is to compile a matric of experiments and perform simulation experiments in order to compare both concepts.

The modern industry has an increasing demand for simulation software able to help workers and decision-makers visualize the outputs of a specific process in a fast, accurate way. In this report, a comparative study between FACTS (Factory Analyses in ConcepTual phase using Simulation), Plant Simulation, and PSE (Production System Engineering) Toolbox is done regarding their capacity to simulate models with increasing complexity, how accurate they are in their outputs with different optimized buffer allocations, and how well they perform on the task of detecting the bottlenecks of a process. Benchmarking simulation software requires an experimental approach, and for gathering and organizing all the data generated using external programs like MATLAB, C, Excel, and R are used. A high level of automatization is required as otherwise the manual input of data would take too long to be effective.The results conclude on major concordances among FACTS and Plant Simulation as the most used commercial DES (Discrete Event Simulation) software and a more mathematical-theoretical approach coming from PSE Toolbox. The optimization done in the report links to sustainability, with an enhanced TH improving the ecological, social and economic aspects, and to Lean philosophy using lean buffers that smooth and improve the production flow.