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.

När ett tillverkande företag vill öka sin marknadsandel behöver de i allmänhet öka sin produktion. För att kunna göra detta på ett kostnadseffektivt sätt är det viktigt att veta vilka faktorer som begränsar produktionssystemet, dessa benämns ofta som flaskhalsar. Ett produktionssystem är dock inte ett statiskt system vilket innebär att flaskhalsarna i ett system inte heller är statiska. De kan flytta på sig på både lång och kort sikt.   Syftet med denna fallstudie är att undersöka flaskhalsarna i ett produktionssystem och hur dessa förflyttar sig, vilka förbättringar som kan göras för att förbättra flödet i produktionssystemet. Data om produktionssystemet har samlats in med studier av databas, tidsstudie och samtal/intervjuer. Dessa data har nyttjats i en simuleringsmodell som framtagits med hjälp av FACTS-analyzer. Denna modell har studerats samt använts för att genomföra experiment. Bland annat har flermålsoptimering med SCORE metoden använts för att hitta systemets primära och sekundära flaskhalsar.   Studien visade att en station på svetsavdelningen var den huvudsakliga flaskhalsen i produktionssystemet och att den sekundära flaskhalsen i systemet låg i avdelningen efter, måleriavdelningen. Studien tog också fram en optimerad förbättrings plan för fabriken upp till 260 tillverkade båtar på ett år. / When a manufacturing company intends to increase their market share, they generally need to increase their production as well. In order to achieve this in a cost-effective manner they must be aware of which factors are limiting the production system, these factors are generally known as bottlenecks. A production system is however not a static system, this means that the bottlenecks won’t be static either. They can move both in the long term and short term.   The aim of this case study is to examine the bottlenecks in a system and their movement. As well as which improvements could be applied in order to improve the flow in the production system. Data concerning the production system has been collected through studies of internal databases, time studies and interviews. This data has been used in a simulation which has been constructed with FACTS-analyzer. The model has been studied and used for experimentation, for example, multigoal-optimization with the SCORE-method, which has been used in order to find the primary and secondary bottlenecks of the system.   The study shows that a station in the welding department was the main bottleneck in the productions system and the secondary bottleneck is in the department after, the paint shop. The study also found an optimized improvement plan for the factory up to 260 boats produced each year

There are manufacturing systems all over the world and all of them present dif- ferent characteristics. To get close to those manufacturing systems and aid them to analyze data and improve their efficiency, it arises FACTS Analyzer®. The present project concerns the development of a bottleneck analysis using REVERSE- SCORE (Simulation based COnstraint REmoval), feature included in FACTS Ana- lyzer. It is used Simulation-based Multi-Objective Optimization (SMO) to ana- lyze the different variables of a production line and investigate how to best extend previous application of SMO for bottleneck detection to not only consider im- provements of system parameters but also degradations of them. Degrading some system parameters can have many hidden advantages such as reduce power con- sumption, increase material efficiency or lengthen the useful life of the machines or tools, advantages that can draw near sustainability.

Genom rapporten kommer kunskapen öka kring identifiering och reducering av flaskhalsar baserade på simuleringsverktyget Facts Analyzer och lean-verktyg. Den ökade kunskapen kommer generera möjligheter för företag att arbeta på ett strukturerat och effektivt vis genom en egenutvecklad arbetsmodell. Modellen kommer ge förutsättningar för företag att öka sin produktivitet och samtidigt reducera totala kostnaderna. Metoderna som arbetsmodellen bygger på är kvantitativ, kvalitativ, abduktion och förverkligas genom tillämpning på ett fallföretag där syftet är att undersöka applicerbarheten och ifall produktionen kan effektiviseras.  Med simuleringsverktyg skapas tydliga och fakta-baserade resultat på flaskhalsar och vad olika förbättringsalternativ har för påverkan på produktionen, därmed anses det vara ett bra verktyg att basera beslut på innan investeringar genomförs. Utifrån de identifierade flaskhalsarna, med hjälp av simuleringsverktyget, är det bevisat att lean-verktyg kan användas för att optimera produktion och reducera icke värdeskapande moment. Exempelvis visar resultatet att 5S, Kaizen, Poka Yoke, Total Productive Maintenance och Overall Equipment Efficiency är effektiva lean-verktyg.  För att öka produktionskapaciteten handlar det om att först identifiera flaskhalsarna genom simuleringsverktyget. Därefter beräknas flaskhalsens OEE-värde som skapar indikationer om begränsningarna och därmed belyser vart förbättringsförslag behövs. Genom indikationerna tillsammans med ytterligare lean-verktyg skapas därefter förbättringsförslag med fokus på att reducera flaskhalsen. För att däremot identifiera totalkostnadsreducering och icke värdeskapande aktiviteter används istället observationer och intervjuer med personalen. Därefter utvecklas förbättringsförslag, liksom för produktionskapaciteten, genom lean-verktyg för att minimera Muda. / Through the report, knowledge will increase regarding the identification and reduction ofbottlenecks based on the simulation tool Facts Analyzer and lean-tools. The increasedknowledge will generate opportunities for companies to work in a structured and efficientway through a own developed work model. The model will provide the conditions forcompanies to increase their productivity and at the same time reduce total costs. The methodson which the work model is based are quantitative, qualitative, abduction and are realized through a case company where the aim is to investigate the applicability and if productioncan be made more efficient. With simulation tools, clear and fact-based results are created on the effect differentimprovement options have on production, and thus it is considered a good tool to basedecisions on before investments are made. Based on the identified bottlenecks, with the helpof the simulation tool, it is proven that lean-tools can be used to optimize production andreduce non-value-creating activities. For example, the results show that 5S, Kaizen, PokaYoke, Total Productive Maintenance and Overall Equipment Efficiency are effectivelean-tools. To increase production capacity, it is a matter of first identifying the bottlenecks through thesimulation tool. The bottleneck's OEE value is then calculated, which creates indications ofthe limitations and thus highlights where improvement proposals are needed. Through theindications together with additional lean-tools, improvement proposals are then created with afocus on reducing the bottleneck. In contrast, to identify total cost reduction andnon-value-creating activities, observations and interviews with the staff are used instead.Improvement proposals are then developed, as for the production capacity, through lean-toolsto minimize Muda.

To stay competitive in today's market, organizations focus on efficiency to reduce costs. Since there are still processes that are manually handled, there is a risk of affecting workers health during streamlining. Volvo CE Braås are currently working with a takt time of 35 minutes throughout their facility. They are looking to implement a takt flow system on their Pallet breakdown disassembly line to unify the systems within the company. The current situation of the pallet breakdown consists of variation, ergonomic issues, inconsistencies, disturbances and lay-out problems. Main problems have remained unidentified. The goal of the thesis has been to determine how optimization as well as, takt time implementation affects the workers. The aim of the thesis has been to analyze their current situation, present relevant changes to be made and to improve the ergonomics of the employees. Methods such as flow mapping, surveys, gemba walks and interviews have contributed to a basis of understanding. The methods have, together with selected theory, contributed to important knowledge and understanding of the disassembly system, that has led to conclusions and recommendations regarding the impact of optimization and takt time implementation on ergonomics. By using ergonomic guidelines together with discrete event simulation, an identification of human factors when optimizing has been detected. For Volvo CE to successfully implement takt time, several optimizations are needed together with relevant investments to ensure that the ergonomic values are kept on an appropriate level when the frequency of tasks increases. As a conclusion, to optimize a system which has a direct impact on the employees, there is a need to investigate the ergonomic values of today together with values after optimization. Optimization can not occur without investing in tools.

This thesis will provide knowledge on how to maintain a well developed flow of material while at the same time finding an optimal level of capacities for buffers. Simultaneously, aspects that allow for positive sustainability practices will be regarded.  Buffers have a considerable impact on the performance of a production system. However, the process of optimizing buffers remains a complex task, and is therefore in need of further research. Through a thorough data collection process, simulation modeling and Multi-objective Optimization, the authors will present evidence-based recommendations for managing buffers in an optimal manner. The case company currently has two buffer zones that are to be investigated if they could be improved by finding an optimal capacity level. The current flow of material consists of certain variations in the components that will be taken into consideration, some variations need further investigation in order to be representative and applicable to this study. By applying amongst other things, Lean concepts, Gemba walks, simulation modeling, interviews and knowledge within the specific field of buffer optimization, the authors were able to provide evidence-based recommendations. These recommendations both take into account optimal buffer capacities as well as brief sustainability and economical aspects. The authors have found that one buffer zone has the potential of being removed, which will contribute to positive environmental aspects. However, if this solution is to be applied, the need of planning and managing the distribution of components is required.  Another buffer zone has been investigated by applying the concept of Multi-objective Optimization, where the objectives are to maintain high throughput while minimizing the buffer capacities. The optimization procedure generated a decrease in buffer capacities in the zone by a total of 35%. This newly acquired space can either be used for other manufacturing processes, or be discontinued, which would decrease the energy consumption and positively affect the sustainability aspect.