Diploma thesis deals with the process of optimizing the material flow in a manufacturing company. The critical path of project is found through the stochastic method of Program Evaluation and Review Technique (PERT). On the whole process is compiled simulation in the program Technomatix Plant Simulation as an alternative method for evaluation of the project. Both methods are built into confrontation and are set out proposals for possible solutions to optimize processes and their evaluation. Thesis is prepared on the basis of literature dealing with the topic, based on internal company resources and expertise of the author internal company processes.

The diploma thesis deals with using discrete event simulation as a tool for supporting decision-making process in the company with usage of simulation software Plant Simulation. This work briefly introduces business process modeling and simulation problems. In the diploma thesis there two varieties two varieties of supplying parts, compared with each other in a process view and there is a particular proposal solution, including the economical evaluation.

The aim of this thesis is to create simulation model of a conveyor node in the field of sequential stack topcoat paintshop of ŠKODA AUTO a.s. in Mladá Boleslav. Simulation model is create in Plant Simulation. The chapters of this thesis describes the overview of conveying technology used for the transportation of bodies in the solved area, basics of discrete simulation, describe solved area and process of creation a simulation model. Using the simulation model is tested overall throughput of solved area, when changes input parameters. From results of experiments are deducted the conclusions.

Volvo Personvagnar är ett av de starkaste varumärkena i bilindustrin, med en lång och stolt historia av världsledande innovationer. Fabriken i Skövde tillverkar motorer i både bensin- och dieselvarianter. I framtiden planerar Volvo att införa nya typer av motorer med gruppnamnet VEA, Volvo Environmental Architecture. Dessa nya motorer kommer att vara standard i alla nya Volvobilar, men tillverkning av de gamla modellerna kommer att finnas kvar För att förstå hur de nya transportsystemen i fabriken kommer att fungera tillsammans med de gamla transportsystemen och för att veta om de transportsystemen kan hantera framtidens krav krävs en simuleringsmodell. Under våren 2011 gjordes ett liknande projekt, då en simuleringsmodell av transportsystemen skapades. Men eftersom modellen var för komplicerad och krävde mycket simuleringstid beslutades att en ny modell ska byggas för att kunna hantera optimering. Det finns tre huvudsakliga transportsystem, automatiskt styrda fordon (AGV), elektrisk hängbana (EHB) och manuella transporter med truckar. Detta projekt syftar till att simulera de automatiska transportsystemen mellan bearbetningsfabrikerna och monteringen, och att se till att Volvo klarar framtidens krav genom att: Samla in alla uppgifter som påverkar transportsystemen, så som transportlayouter, tillgänglighet, kommunikationsprotokoll och så vidare. Detta för att vara säker på att en realistisk simuleringsmodell kan byggas. Bygga en simuleringsmodell över det nuvarande systemet och validera att modellen överensstämmer med det verkliga systemet, genom att jämföra in- och utgångar, så som produktionsplan, lagerutnyttjande, produktion per timme under en viss tid. Utveckla och skapa en modell för ett framtida scenario. Simuleringsmodellen ska kunna varieras i olika buffertstorlekar, transportenheter, skiftformer och kunna klara av att hantera olika testscenarion beroende på kundernas efterfrågan. Analysera resultaten av den framtida modellen för att besvara frågorna: Kommer transportsystemen klara av att transportera i och med den ökade takten? Hur många AGVer och EHB-vagnar är nödvändiga? Vilka typer av skift bör användas i de olika fabrikerna och vilken kapacitet för varje lager behövs vid de olika scenarierna? I detta projekt används simuleringsprogrammet Tecnomatix Plant Simulation 9, eftersom det kan hantera mycket komplexa modeller. Det kommande användandet av vår simuleringsmodell för Volvo är ytterligare en anledning till varför detta program väljs då Volvo är på gång att införskaffa sig Plant Simulation. Därför kan den modell som utvecklats under detta projekt tillämpas av Volvo i framtiden för att besvara framtida frågor. Vissa förenklingar görs i projektet och i modellen, händelser som inte är viktiga för resultatet är förenklade till en process. Till exempel påverkar tillverkningsprocesser inte transportsystemet mer än produktionens takt. Genom att förenkla modellen kan den bli mycket snabbare och enklare att använda då det kommer att finnas mindre data att hantera under simuleringen. Två scenarion har körts i projektet där ena scenariot bygger på att alla motortyper testas varav det andra scenariot testar enbart de nya motortyperna. Resultatet från scenario 1 har visat att Volvo klarar att producera enligt planerat kundbehov genom att införskaffa nya AGVer och att göra om skiftformerna för både montering samt bearbetning. Antalet EHB-vagnar som behövs är mindre än vad som finns tillgängligt i dagens läge. Resultaten från scenario 2 visar att Volvo klarar att producera enligt kundbehov genom att införskaffa fler AGVer än vad som krävs till scenario 1. Antal EHB-vagnar som behövs är också mindre i detta fall än vad som finns tillgängligt i dagens läge. / The Volvo Car Corporation is one of the strongest brands in the car industry, with a long and proud history of world-leading innovations. The factory in Skövde produces engines in both petrol and diesel variants. In the future Volvo is planning to introduce new types of engines with the group name VEA. These new engines will be the main engines in all new Volvo cars, but the old models will remain indefinitely. To understand how the new transport systems in the factory will work together with the old transport systems and also to know if the transport systems can handle the future demands, a simulation model is required. In the spring of 2011 a similar project was done where a simulation model of the transport systems was built, but since the model was too complex and required a lot of simulation time it was decided that a new model will be built. There are three main transport systems; Automated guided vehicles (AGV), electric track systems (EHB) and manual transports with trucks. This project is aimed to simulate the automated transport systems between the Manufacturing factories and Assembly factories, to make sure that Volvo can handle future demands by: collecting all data that affects the transport systems, such as transport layouts, availability, communication protocols and so on, to be certain that a realistic simulation model can be built; building a simulation model over the current system and validating that the model conforms to the real system by comparing inputs and outputs, such as production plan, store utilization, throughput per hour, over a certain period of time; developing and create a model for a future scenario. The simulation models should be able to vary in different buffer sizes, quantities of transportation and be able to create various test scenarios depending on customer demand; analyzing the results of the future model to answer the questions: will they be able to keep up with the customer demands with the planned transport systems, how many AGVs and EHBs are necessary, shifts that is necessary for each factory and the capacity that is needed for each store; In this project Tecnomatix Plant Simulation 9 is used as the simulation software since it can handle very complex models. The future adoption of our simulation model by Volvo in Plant Simulation is another reason why this software is chosen. Therefore, the model developed during this project can be applied to answer future questions. Certain simplification is made in the project and in the model; events that are not important to the outcome are simplified to one process. For example, manufacturing processes do not affect the transport system other than the throughput. By simplifying the model, it may become much faster and easier to use since there will be less data to manage during simulation. Two scenarios have been simulated in this project where one scenario is based on testing all engine types whereas the other scenario only tests the new engine types. The result from scenario 1 has shown that Volvo will be able to produce according to the customer demands by acquiring new AGVs and by making certain shift arrangement for the different lines in the factory. The amount of EHB wagons needed is less than the current amount today. The results from scenario 2 shows that Volvo will produce according to the customer demand by acquiring more AGVs than needed for the scenario 1. The amount of EHB wagons needed in this case is also less than what exists today.

BillerudKorsnäs har gjort en satsning på sin anläggning i Rockhammar då produktionen utökas genom flertalet utbyggnationer av den existerande anläggningen. En del av anläggningen som byggs ut är balningslinjen, den del av produktionen där pappersmassa pressas till solida balar och paketeras i emballage. Målet med utbyggnationen av balningslinjen är att klara av att hantera den ökning i produktionsflödet som den utökade produktionsanläggningen bidrar med. Balningslinjen planeras att byggas ut i tre efterföljande steg och på så sätt suggestivt öka produktionskapaciteten. Examensarbetets syfte var att ta fram simuleringsmodeller för den nya balningslinjen i det diskreta hybridsimuleringsprogrammet Plant Simulation och på så sätt uppskatta vilken produktionskapacitet anläggningen har efter ombyggnationen. Effekten av förändringarna analyserades genom att simulera olika scenarion i modeller baserade på de olika steg av utbyggnationer balningslinjen genomgår. Resultatenanalyseras för maskinbeläggningsgrad, produktionshastighet och flaskhalsar. På BillerudKorsnäs Rockhammar har de inte tidigare använt sig av simuleringsstudier men var positivt inställda då de såg möjligheterna till att finna information som kan vara till hjälp i det arbete som pågår för att dimensionera och implementera den nya balningslinjen. Simuleringsstudier ger möjlighet att skapa förståelse för processer och är ett effektivt sätt att uppskatta beteendet hos anläggningar som inte ännu finns i verkligheten. De metoder som använts för att skapa en nulägesanalys är intervjuer, historiska data, tidsstudier samt maskindata över de existerande komponenter som kommer att ingå i den nya anläggningen. Simuleringsmodellerna byggdes upp i små steg, där varje förändring testades och utvärderades innan nästa iteration av modellen. Modellvalidering var även en viktig del av examensarbetet då felaktiga indata äventyrade projektets giltighet. Simuleringsstudierna visar att de kapacitetsmål företaget förväntade sig uppnå kommer att uppfyllas. Flaskhalsanalyser visar att det i viss mån finns möjlighet att uppnå en något högre kapacitet i anläggningen på bekostnad av en mer störningskänslig produktionsprocess. Den simuleringsmodell som tagits fram kan i framtiden användas för att testa förändringar i produktionsflödet på balningslinjen. / BillerudKorsnäs made an investment effort at their facility in Rockhammar, were there production capacity was to be increased by numerous constructions. One of those specifically is the expansion of the baling-line, a part of the production process were the pulp is pressed into bales and packaged. The purpose of the expansion of the baling-line is to manage the increased productionflow, generated by the overall expanded facility. The baling-line is to be expanded in three subsequent steps and thereby successively increase its production capacity. The purpose of this thesis was to produce simulation models in the discrete hybrid simulation software Plant Simulation; thus approximate the production capacity after the expansion. The effect generated by these changes was approached by simulating different scenarios based upon the three steps the facility will be going through. The results was analyzed centered upon working percentage of the production resources and bottleneck analyses. At BillerudKorsnäs Rockhammar there were no previous attempts at performing simulation studies. However, they withheld a positive attitude towards the notion, as they saw the possible benefits from gaining information that could be of use, during their ongoing undertaking in planning and dimensioning the new baling-line. As simulation studies makes it possible to acquire process knowledge and is regarded as an effective method to approximate the behavior of a facility that has not yet been implemented. The situation analysis was performed by methods such as interviews, collecting historical production data, time studies and gathering machine specifications of the components that was to be transferred to the new facility. The simulation models was produced by small steps and verified through every iteration. Model validation stood out as an important part of the project, as inaccurate input data could jeopardize the projects validity. The simulation studies indicated that the target production capacity, set by the company, was to be fulfilled. The bottleneck analysis specified that there was a margin for a slightly higher capacity; thought at the cost of a more susceptible production process. The simulation models produced during this thesis can be used for further test in changes of the production flow at the Rockhammar baling-line.

ABSTRACT The aim of industrial production changed from mass production at the beginning of the 20th century. Today, production flexibility determines manufacturing companies' course of action. In this sense, Volvo Group Trucks Operations is interested in meeting customer demand in their assembly lines by adjusting manpower. Thus, this investigation attempts to analyze the effect of manning on the main final assembly line for thirteen-liter heavy-duty diesel engines at Volvo Group Trucks Operations in Skövde by means of discrete-event simulation. This project presents a simulation model that simulates the assembly line. With the purpose of building the model data were required. One the one hand, qualitative data were collected to improve the knowledge in the fields related to the project topic, as well as to solve the lack of information in certain points of the project. On the other hand, simulation model programming requires quantitative data. Once the model was completed, simulation results were obtained through simulation-based optimization. This optimization process tested 50,000 different workforce scenarios to find the most efficient solutions for three different sequences. Among all results, the most interesting one for Volvo is the one which render 80% of today’s throughput with the minimum number of workers. Consequently, as a case study, a bottleneck analysis and worker performance analysis was performed for this scenario. Finally, a flexible and fully functional model that delivers the desired results was developed. These results provide a comparison among different manning scenarios considering throughput as main measurement of the main final assembly line performance. After analyzing the results, system output behavior was revealed. This behavior allows predicting optimal system output for a given number of operators.

This thesis work was carried out at a manufacturing plant in Sweden and they are producing a different kind of components for the company. This thesis work was about an assembly line in the factory where they needed a simulation model in Plant Simulation. The main goal of the thesis work was to break down different losses, building a simulation model and compare it if the results are the same as the real assembly line with similar characteristics. The assembly line consists of several workers and AGVs with three u-shaped lines. Frame of reference describes topics that are related to the project. It consists of theories about simulation, collection of data, the bottleneck of the production line, integrated manufacturing systems and flexible workers. The chapter of literature review presents researches on similar studies, in this case, simulation, bottleneck, and workers in the assembly line. In the chapter Simulation model, there will be an explanation of how data got collected, the transformation of raw data and building a simulation model of it. Also the way the model was programmed and built. Result and analysis, the focus is to analyze the throughput, lead time and work in process parameters to get a steady state graph and confidence interval. This chapter also shows how long time does the model need for warm up and how many replications it needs to be more accurate. Discussion part reviews the whole project and its progress. It covers problems that authors got through, at the same time learning and getting a new experience of tools and methods that were used in this project.

Following an introduction, the author describes Texas A&M University and its utilities system. After that, the author presents how to construct simulation models for chilled water and heating hot water distribution systems. The simulation model was used in a $2.3 million Ross Street chilled water pipe replacement project at Texas A&M University. A second project conducted at the University of Texas at San Antonio was used as an example to demonstrate how to identify and design an optimal distribution system by using a simulation model. The author found that the minor losses of these closed loop thermal distribution systems are significantly higher than potable water distribution systems. In the second part of the report, the author presents the latest development of software called the Plant Optimization Program, which can simulate cogeneration plant operation, estimate its operation cost and provide optimized operation suggestions. The author also developed detailed simulation models for a gas turbine and heat recovery steam generator and identified significant potential savings. Finally, the author also used a steam turbine as an example to present a multi-regression method on constructing simulation models by using basic statistics and optimization algorithms. This report presents a survey of the author??s working experience at the Energy Systems Laboratory (ESL) at Texas A&M University during the period of January 2002 through March 2004. The purpose of the above work was to allow the author to become familiar with the practice of engineering. The result is that the author knows how to complete a project from start to finish and understands how both technical and nontechnical aspects of a project need to be considered in order to ensure a quality deliverable and bring a project to successful completion. This report concludes that the objectives of the internship were successfully accomplished and that the requirements for the degree of Degree of Engineering have been satisfied.

Following an introduction, the author describes Texas A&M University and its utilities system. After that, the author presents how to construct simulation models for chilled water and heating hot water distribution systems. The simulation model was used in a $2.3 million Ross Street chilled water pipe replacement project at Texas A&M University. A second project conducted at the University of Texas at San Antonio was used as an example to demonstrate how to identify and design an optimal distribution system by using a simulation model. The author found that the minor losses of these closed loop thermal distribution systems are significantly higher than potable water distribution systems. In the second part of the report, the author presents the latest development of software called the Plant Optimization Program, which can simulate cogeneration plant operation, estimate its operation cost and provide optimized operation suggestions. The author also developed detailed simulation models for a gas turbine and heat recovery steam generator and identified significant potential savings. Finally, the author also used a steam turbine as an example to present a multi-regression method on constructing simulation models by using basic statistics and optimization algorithms. This report presents a survey of the author??s working experience at the Energy Systems Laboratory (ESL) at Texas A&M University during the period of January 2002 through March 2004. The purpose of the above work was to allow the author to become familiar with the practice of engineering. The result is that the author knows how to complete a project from start to finish and understands how both technical and nontechnical aspects of a project need to be considered in order to ensure a quality deliverable and bring a project to successful completion. This report concludes that the objectives of the internship were successfully accomplished and that the requirements for the degree of Degree of Engineering have been satisfied.

This thesis has been performed in collaboration with Volvo Cars Engine in Skövde, Sweden and Zhangjia-kou, China in order to receive a bachelor degree in automation engineering from the University of Skövde. The project focuses on analyzing the capacity of a future production line by using discrete event simulation. The production line is built in two different discrete event simulation software, FACTS analyzer and Plant Simulation. The focus of the study will be to compare the output results from the two software in order to give recommendations for which software to use in similar cases. This is done in order for Volvo Cars Corporation to have as a basis for further work in similar cases. The aim of the work is to verify the planned capacity of the new production line and to perform a leadership study with Chinese engineers in order to find out how they view the Swedish leadership and how this can be adapted to China and the Chinese culture and give recommendations for future work. The results of the capacity analysis show that the goals of parts produced can be reached for both planned capacities but also that there are potential constraints that have been identified in the system. The results of the leadership study also show that the overall approach should be slightly adapted to be better suited for the Chinese culture. The comparison of the two simulation software suggests that FACTS Analyzer is suit-able to use when less complex logic or systems are represented, however when building more complex models consisting of more complex logic Plant Simulation is more suitable.