This dissertation examines the problems of scheduling and routing automated guided vehicles (AGVs). AGVs are unmanned vehicles following a network of guide paths controlled by a supervisory controller. They represent a highly flexible material moving system well suited to the developing technologies of advanced manufacturing. The research in this area is motivated by the importance of AGVs in modern factories and the inadequacies of current methods of control. These inadequacies include the lack of adequate temporal reasoning, production of vehicle schedules that support automated guided vehicle system (AGVS) rather than global manufacturing objectives, the inability to produce quickest routes for vehicles and the lack of dynamic replanning. Unlike conventional controllers of AGVs the AGV scheduler presented in this dissertation (PRISMM - Planner for Reactive Intelligent Scheduling of Material Movement) considers global manufacturing objectives as well as local AGVS objectives when generating AGV schedules. It exploits novel techniques for routing vehicles that uniquely allow the integration of the shortest or the quickest routes into a timetable of vehicle movements. The techniques guarantee to find a route if one exists and will allow the imposition of deadlines. Algorithms to find a fast route through large or extremely busy route networks have also been derived. These methods will guarantee to find a route between two points as long as the vehicle begins its journey from a reserved parking space. A replanning technique has been proposed for dealing with most common errors of AGV schedule execution. A new method for the most commonly encountered problem requires no reordering of plan steps.

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In today’s fierce competitive global markets, customers are demanding adjustable lot sizes, shorter lead times, higher quality and flexibility; in short, they want it all. In order to stay competitive in the market, companies need to attain both customer satisfaction and cost reduction in production operations. Material Handling Systems (MHS) is the place to accomplish this goal, since they have a direct impact on production. Therefore, the aim of this study was to design an in-house MHS that could be efficient for the production it serves. With this intention, a case-study has been conducted in Bosch Rexroth Japan. During the study, the information gathered through various sources; interviews, observations and measurements. Further, the gathered data is evaluated according to main pillars of the theoretical framework, which includes design principles and physical elements, information and software, human and management. By analyzing the findings from literature review and empirical study, first problems and challenges related to MHSs are identified. Thereafter, possible features that the system should posses are elicited and a design is built out of the selected features. To conclude, the results show that the success is not solely depending on system’s physical attributes; on the contrary, it is more related to rapid and accurate information sharing within the system. Another vital element is the interaction between system and the people, who are utilizing and operating the system. In general terms, the research took MHS design problems from one-dimensional equipment selection processes and enriches them by adding information sharing, human and management angles to design steps.

Um Maßnahmen zu Verbesserungen an einem mechatronischen Handhabungssystem für den Transport von Windeln vorzunehmen, wäre eine strukturierte Methode vorteilhaft, da aktuell angewandte Vorgehensweisen durch Intuition geprägt sind. Diese intuitiven Vorgehensweisen bergen Nachteile sowohl in der Objektivität als auch bei der Dokumentation. Aus diesem Grund ist für das beschriebene mechatronische Handhabungssystem eine Methode zur Unterstützung des Entscheidungsprozesses entwickelt worden. Mit Hilfe eines Probandentests erfolgte eine erste Überprüfung. Durch die Methode erhält der Anwender eine Schritt für Schritt Anleitung, welche sich durch ein möglichst rationales Vorgehen auszeichnet und in der Lage ist die Wirkung subjektiver Einflüsse bei notwendigen Entscheidungen zu reduzieren.

Im Rahmen des Forschungsvorhabens wurde das Wirken von Autokorrelation auf das Verhalten von Materialflusssystemen anhand von Realdaten analysiert. Hintergrund waren theoretische Untersuchungen, die einen deutlichen Einfluss von abhängigen Ereignissen auf die Leistung von Materialflusssystemen erkennen lassen. Mit Hilfe der Projektpartner konnte eine große Menge von Echtdaten zusammengetragen werden. Insgesamt wurden 52 Datensätze auf zeitliche Abhängigkeiten der Ereignisse untersucht. Dabei bestätigte sich die Vermutung, dass Autokorrelation durch z. B. Batchbildung oder Prioritätsregeln allgegenwärtig in Erscheinung tritt. In ca. 95 % aller Datensätze konnte signifikant Autokorrelation nachgewiesen werden. Im Rahmen der Untersuchung konnten eine Reihe unterschiedlicher Korrelationsstrukturen nachgewiesen werden. Diese unterschieden sich sowohl in der Stärke, in der Ausprägung (positiv oder negativ) als auch im Abklingverhalten. Der größte Einfluss auf das Systemverhalten geht von der Stärke und der Ausprägung der Autokorrelationskoefizienten aus. Im Rahmen des Projektes konnten unterschiedliche Verfahren zur Erzeugung autokorrelierter Ereignisse identifiziert und bewertet werden. Beispielhaft zu erwähnen ist die TES-Methode, der Minification- bzw. Maxification-Ansatz oder spezielle Markov-Ketten. Als am besten geeignet hat sich der sog. ARTA-Ansatz herausgestellt. Der ARTA-Ansatz wurde in einer Java-basierenden Software-Bibliothek namens „JARTA“ umgesetzt. Diese ist frei verfügbar sowie variabel und einfach einsetzbar. Durch das Forschungsvorhaben wurde das Bewusstsein um das Auftreten und Wirken von Autokorrelation in logistischen Systemen geschärft. Projektpartner bestätigen, dass durch gezielte Untersuchung auf Abhängigkeiten Fehler bei der Systementwicklung und beim Systembetrieb verringert werden konnten.

Um Maßnahmen zu Verbesserungen an einem mechatronischen Handhabungssystem für den Transport von Windeln vorzunehmen, wäre eine strukturierte Methode vorteilhaft, da aktuell angewandte Vorgehensweisen durch Intuition geprägt sind. Diese intuitiven Vorgehensweisen bergen Nachteile sowohl in der Objektivität als auch bei der Dokumentation. Aus diesem Grund ist für das beschriebene mechatronische Handhabungssystem eine Methode zur Unterstützung des Entscheidungsprozesses entwickelt worden. Mit Hilfe eines Probandentests erfolgte eine erste Überprüfung. Durch die Methode erhält der Anwender eine Schritt für Schritt Anleitung, welche sich durch ein möglichst rationales Vorgehen auszeichnet und in der Lage ist die Wirkung subjektiver Einflüsse bei notwendigen Entscheidungen zu reduzieren.

When developing a material handling system (MHS) it is crucial to master the various aspects for each developing step to increase the efficiency of the MHS. This Master’s thesis is aimed to identify conceptual solutions of a MHS and analyse the advantages and challenges for each of the developed concepts. Automation and implementation into a factory setting has taken into great consideration for this study. Two research questions (RQ) and three goals were formulated: RQ1: Which conceptual solutions of a material handling system for a high-pressure processing machine can be developed? RQ2: What are the challenges and advantages of each designed concept in terms of automation and implementation? Goal1: Develop three conceptual solutions of a material handling system. Goal2: Identify target specifications and determine their margin and ideal values for evaluation of the three conceptual solutions. Goal3: Analyse each developed material handling system and determine which concept is best out of the three in relation to the target specifications Automation has proven to be a key cause for achieving an effective MHS on the market and the two main reasons for this are, one: the elimination of ongoing labour cost and second; an increase of the overall safety factor for the system. The thesis, using the design research methodology (DRM) type two, consisting of an in-depth literature review and case study that contributed to evaluation and comparison of developed concepts. The literature review contributed to identifying the necessary steps of the structure of the MHS and required tools for the development phase. For the case study, the projects developing phase were taken from Ulrich, Eppinger and Yang (2020) ´s developing method. Identified tools and knowledge from the literature was used throughout the entire case study such as multi criteria decision making (MCDM), computer aided design (CAD), material flow patterns, automation and high-pressure processing (HPP). The findings of the case study showed that there are multiple concepts that can be developed. However, fully automated MHS are preferred when analysing the advantages and challenges for each fully developed MHS concept. The study resulted in three MHS concepts. Two fully automated ones and one semi-automated. The two fully automated MHS concepts showed more promising results than the semi-automated one. This was based on the MCDM-matrix which evaluated every MHS concept in relation to multiple criteria and failure mode effect analysis (FMEA) which investigated safety factors such as human safety and risk of MHS failure. Calculations such as capital cost and operational cost was also considered when analysing the differences between the MHS concepts. A fully automated MHS is not necessarily more costly in capital investment compared to semi-automated systems for the same HPP machine. Human labourers are, in semi-automated systems however, more precise in packaging operations, but also raises the operational costs substantially.

Given that the end-customer has become more demanding, the retailer has to deliver products according to the market demands, which have forced manufacturing companies to constantly search for new opportunities to reduce costs and improve efficiency. It is, therefore important to choose suppliers that are able to compete with the market demands.The market demands in the textile industry have lead to shorter product life cycles, which have caused manufacturers to deliver flexibility with high technology to compete successfully on the global market. To achieve the market requirements the underlying factor is to be aware and optimally use and control time. New technology can have a major influence in the production development, if the company choose to take benefit of the advantages, by optimal allocation of the internal resources the productivity and efficiency will increase, to accomplish a competitive advantage. One way to achieve this is by investing in a Unit Production System.In our thesis we have questioned what the main driving forces for an apparel manufacturing company is when it chooses to invest in new technology. Our previous knowledge says that manufacturing companies are forced to invest in a UPS to deliver to the market demands; therefore our sub-question investigates whether market demands impact the investment in new technology.In our theory we have concluded aspects in our study which is important for the reader to have an understanding of. We describe the textile industry from the view of Porters value chain and elaborate some concepts and their definitions, which will be used as a basis throughout our thesis. Finally we present a model of Five forces that determine industry competition made by Porter, to use as an analysis method when investigating whether an UPS may bring a competitive advantage.Our field study has been carried out in South India, where we have visited five textile factories and interviewed managers. We have questioned their decision-making judgment about implementing or choosing not to implement a UPS. Other production factors and general information about the companies have been asked to have an understanding of underlying factors. We have also had the opportunity to observe their manufacturing handling systems and seen how they have chosen to use this in an optimal way.Our previous knowledge of this subject has routed to that our research will be performed in a hermeneutics scientific approach. Our role as researchers has during the study been open-minded, subjective and committed according to a hermeneutics view. / Program: Textilekonomutbildningen

In today’s world, simulation and optimization are playing a vital role in reducing the time, cost and preserving resources. In manufacturing industries, there are ample amount of problems that go on with the expansion of the industry. In such cases, to tackle these problems simulation can be helpful to check whether any change in the current situation makes any effect on the current efficiency of the overall plant. In the presented case study, a solution to the problem of internal and external logistics has been designed by using simulation and optimization to improve part of a material flow of an organization. Basically, the organization whose major production is established in the south of Sweden deals with the manufacturing and assembly of equipment. Before the dispatch, all of them go to the painting section which is the expansion of the present shop floor. However, the design and analysis of the material handling system to feed the new painting line which is going to be established by the organization is the aim of this case study. While achieving this aim the literature regarding the discrete event simulation, Lean and Simulation-Based optimization related to the material handling system has been done. Furthermore, the appropriate material handling systems along with the different scenarios were suggested to reduce the cost and the lead times between the production line and the new painting line. To support this process a methodology combining simulation, optimization and lean production has been implemented under the framework of the design and creation research strategy. In the Kaizen workshop organized at a company with managers and stakeholders, the designed scenarios were presented and after some discussion one of them was chosen and the selected scenario was designed and optimized. Moreover, the Simulation-Based multi-objective optimization has been helpful for the optimization of the designed model proposed as a final solution.

The aim of the master’s thesis was to design ventilation and cooling systems in a three-storey mixed-use building, which contained three apartments and two dentists’ surgeries. Two independent ventilation systems were designed in the building, with respect to different purposes of the indoor spaces. The mechanical cooling system was proposed in some of the rooms to improve thermal comfort in summer. The thesis includes calculations of building heat gains, heat losses, air exchange rates and the dimensioning of the ventilation and cooling systems. The thesis also comprises design calculations and technical drawing.