The purpose of this master thesis is to develop a model for assessing cost effectiveness of facility layouts. A critical literature review of the available relevant models as well as theories was performed in accordance to this purpose. After this a model was developed in order to cover lacks in existing theories. The aim of the model is to evaluate different facility layouts, from both economical and working environmental aspects. The model as a whole is about evaluating, creating and selecting the most preferable facility layout. In this thesis a case study has been performed for testing the developed model. The case company for this testing was the Mail Terminal in Alvesta, which is a part of Posten Sweden AB. The mail terminal receives, sorts and distributes the mail further. The result of this thesis is that, by following the model the authors were able to evaluate all the layouts and also to create the most preferable one. This thesis provides a general model in a structured way, primary aimed to be used for manufacturing companies. Further researches could be to test the model on service producing companies and to define to what extent the model can be generalised. / Syftet med denna magisteruppsats är att utveckla en modell för att utvärdera kostnadseffektiviteten av anläggningslayouter. En kritisk litteraturundersökning av tillgängliga relevanta modeller samt teorier genomfördes i enlighet med syftet. Därefter utvecklades en modell för att täcka brister i existerande teorier. Syftet med modellen är att utvärdera olika layouter, från både ett ekonomiskt- och arbetsmiljös- perspektiv. Modellen i sin helhet handlar om att utvärdera, skapa och välja den mest fördelaktiga layouten. En fallstudie har genomförts i denna uppsats för att testa den skapade modellen. Fallföretaget för att testa modellen var Postterminalen i Alvesta, som är en del av Posten Sverige AB. Postterminal tar emot, sorterar och distribuerar posten vidare. Resultatet av denna uppsats är att genom att använda modellen lyckades författarna utvärdera alla layouter och även skapa den mest fördelaktiga layouten. Denna uppsats bidrar med en strukturerad generell model, som främst riktar sig till producerande företag. Fortsatt forskning skulle kunna vara att testa modellen på service baserade företag och att definiera till vilken omfattning man kan generalisera modellen.

This thesis presents an application that performs positioning of modules automatically based on given data for every module, and the development of it. The basis of the application is from a previous thesis code. On top of that code, more features and error handling has been added, as well as fixes for various bugs. A stress test has been performed and further development possibilities are being presented. The thesis work was carried out at Toyota Material Handling Mjölby (TMH) and was made in parallel with another thesis by Fredrik Holden who was generating data for the application. For a complete understanding of the theory and background, please also read Holden’s thesis report “Development of method for automated positioning of 3D-representations of a modularized product”, as well as the former thesis  ”Analysis for Automated Positioning of 3D-representation of a Modularized product””. / Detta examensarbete presenterar en applikation som positionerar moduler automatiskt med hjälp av given data för varje modul, samt utvecklingen av applikationen. Applikationen bygger på kod från ett tidigare examensarbete. Ovanpå den koden har flera egenskaper och felhanteringar lagts till, samt har olika buggar fixats. Ett stresstest har också utförts och framtida utvecklingsmöjligheter presenteras. Examensarbetet genomfördes på Toyota Material Handling Mjölby (TMH) och gjordes parallellt med ett annat examensarbete av Fredrik Holden som genererade data för applikationen. För en fullständig förståelse angående teorin bakom samt bakgrunden till examensarbetet, vänligen läs också Holdens rapport ”Developmentof method  for automated positioning of 3D-representations of a modularized product”, samt rapporten från föregeånde examensarbetet ”Analysis for Automated Positioning of 3D-representation of a Modularized product”.

Im Kern der vorliegenden Arbeit wird eine neue Vorfahrtstrategie zur Steuerung von Materialflüssen an Zusammenführungen vorgestellt. Das Hauptanwendungsgebiet stellen innerbetriebliche Transportsysteme dar, wobei die Erkenntnisse auf beliebige Transport- bzw. Bediensysteme übertragbar sind. Die Arbeit grenzt sich mit der Annahme autokorrelierter Ankunftsprozesse von bisheriger Forschung und Entwicklung ab. Bis dato werden stets unkorrelierte Ströme angenommen bzw. findet keine spezielle Beachtung autokorrelierter Ströme bei der Vorfahrtsteuerung statt. Untersuchungen zeigen aber, dass zum einen mit hoher Konfidenz mit autokorrelierten Materialflüssen zu rechnen ist und in diesem Fall zum anderen von einem erheblichen Einfluss auf die Systemleistung ausgegangen werden muss. Zusammengefasst konnten im Rahmen der vorliegenden Arbeit 68 Realdatensätze verschiedener Unternehmen untersucht werden, mit dem Ergebnis, dass ca. 95% der Materialflüsse Autokorrelation aufweisen. Ferner wird hergeleitet, dass Autokorrelation intrinsisch in Materialflusssystemen entsteht. Die Folgen autokorrelierter Prozesse bestehen dabei in längeren Durchlaufzeiten, einem volatileren Systemverhalten und höheren Wahrscheinlichkeiten von Systemblockaden. Um die genannten Effekte an Zusammenführungen zu eliminieren, stellt die Arbeit eine neue Vorfahrtstrategie HAFI – Highest Autocorrelated First vor. Diese priorisiert die Ankunftsprozesse anhand deren Autokorrelation. Konkret wird die Vorfahrt zunächst so lange nach dem Prinzip First Come First Served gewährt, bis richtungsweise eine spezifische Warteschlangenlänge überschritten wird. Der jeweilige Wert ergibt sich aus der Höhe der Autokorrelation der Ankunftsprozesse. Vorfahrt bekommt der Strom mit der höchsten Überschreitung seines Grenzwertes. Die Arbeit stellt ferner eine Heuristik DyDeT zur automatischen Bestimmung und dynamischen Anpassung der Grenzwerte vor. Mit einer Simulationsstudie wird gezeigt, dass HAFI mit Anwendung von DyDeT die Vorzüge der etablierten Vorfahrtstrategien First Come First Served und Longest Queue First vereint. Dabei wird auch deutlich, dass die zwei letztgenannten Strategien den besonderen Herausforderungen autokorrelierter Ankunftsprozesse nicht gerecht werden. Bei einer Anwendung von HAFI zur Vorfahrtsteuerung können Durchlaufzeiten und Warteschlangenlängen auf dem Niveau von First Come First Served erreicht werden, wobei dieses ca. 10% unter dem von Longest Queue First liegt. Gleichzeitig ermöglicht HAFI, im Gegensatz zu First Come First Served, eine ähnlich gute Lastbalancierung wie Longest Queue First. Die Ergebnisse stellen sich robust gegenüber Änderungen der Auslastung sowie der Höhe der Autokorrelation dar. Gleichzeitig sind die Erkenntnisse unabhängig der Analyse einer isolierten Zusammenführung und der Anordnung mehrerer Zusammenführungen in einem Netzwerk. / The work at hand presents a novel strategy to control arrival processes at merges. The main fields of application are intralogistics transport systems. Nevertheless, the findings can be adapted to any queuing system. In contrast to further research and development the thesis assumes autocorrelated arrival processes. Up until now, arrivals are usually assumed to be uncorrelated and there are no special treatments for autocorrelated arrivals in the context of merge controlling. However, surveys show with high reliability the existence of autocorrelated arrivals, resulting in some major impacts on the systems\' performance. In detail, 68 real-world datasets of different companies have been tested in the scope of this work, and in 95% of the cases arrival processes significantly show autocorrelations. Furthermore, the research shows that autocorrelation comes from the system itself. As a direct consequence it was observed that there were longer cycle times, more volatile system behavior, and a higher likelihood of deadlocks. In order to eliminate these effects at merges, this thesis introduces a new priority rule called HAFI-Highest Autocorrelated First. It assesses the arrivals\' priority in accordance to their autocorrelation. More concretely, priority initially is given in accordance to the First Come First Served scheme as long as specific direction-wise queue lengths are not exceeded. The particular thresholds are determined by the arrival processes\' autocorrelation, wherein the process with the highest volume gets priority. Furthermore, the thesis introduces a heuristic to automatically and dynamically determine the specific thresholds of HAFI-so called DyDeT. With a simulation study it can be shown that HAFI in connection with DyDeT, combines the advantages of the well-established priority rules First Come First Served and Longest Queue First. It also becomes obvious that the latter ones are not able to deal with the challenges of autocorrelated arrival processes. By applying HAFI cycling times and mean queue lengths on the level of First Come First Served can be achieved. These are about 10% lower than for Longest Queue First. Concomitantly and in contrast to First Come First Served, HAFI also shows well balanced queues like Longest Queue First. The results are robust against different levels of throughput and autocorrelation, respectively. Furthermore, the findings are independent from analyzing a single instance of a merge or several merges in a network.

The world becomes more integrated and sophisticated, especially in the birth of advanced technologies, which have influenced all life aspects. Automated systems could be considered an example of those aspects, which have been affected by recent changes in today’s life. The competition in the market is putting increasing pressure on different manufacturing organizations to find the best methods that enable them to stay up to date with the latest technologies in the industrial field. One of the most famous dilemmas that exist in this field is designing an efficient and flexible material handling system. This issue draws the attention of both decision-makers in different companies and software developers who put considerable effort into making that desired system real. Inclusive research needs to be performed to obtain such a system, and the most significant part of the research that requires special attention is the applied methodology.The approach to be adapted determines the degree of stability of a particular material handling system to function effectively in the case studied. Several methods are available and could be implemented to design that effective system such as meta-heuristic algorithms, and approaches that depend on simulation software tools. The latter approach, which is the simulation approach, seems to get increasing attention from developers of the industrial system since it plays a vital role in reducing the cost and preserving available resources. Besides, it helps predict future changes and scenarios of the system to be analyzed.In this project, a discrete-event simulation model was built for the proposed layout of the main shop floor owned by a Swedish manufacturing company. The corporation located in the south of Sweden, and it produces a vast range of manufacture of goods. The chosen methodology is a combination of lean, simulation, and optimization approaches. It has been implemented on the proposed layout in which material is handled into production lines by using automated guided vehicles (AGVs) as a means of transportation. The analysis of results shows potential benefits, where the production process became more efficient and organized since the operational cost has been reduced by decreasing the number of required vehicles. Moreover, the simulation approach facilitated testing new ideas and designing improved scenarios without the necessity to change the current state of the factory layout or disturbing the regular activities.

Warehouse automation is a measure E-commerce companies can take to get a more streamlined flow through their warehouse. Order picking is the most labor intensive task in a warehouse. By automating the order picking process companies can lower their costs and improve their response times. This thesis studies the A-frame, an automated order picking system, at a large online pharmacy, Apotea AB. An A-frame has dispensing channels on its side and a conveyor belt that runs through the entire machine. Products for an order are ejected from the channels onto the conveyor belt and at the end of the machine they are dropped into a box. The box is then sealed, labeled and sent to the customer. For the automatic flow to function correctly, all orders picked by the A-frame need to be complete orders. Complete orders are orders where there are no products missing. To maximize the throughput of the A-frame, an appropriate product allocation will be required. Due to the vast number of combinations, it is extremely difficult to identify an optimal product allocation. This study has examined three different approaches to the product allocation problem for an A-frame. The first two methods are based on ranking the products depending on their quantities sold. The last method uses association rule learning, which is a machine learning technique for finding interesting patterns in a data set. Association rule learning was used to find which products were associated to each other. These associations were then placed in a graph structure and solved using a heuristic. To evaluate the different allocation methods, a simulation model was created. The A-frame was simulated using a discrete event simulation, which meant all methods could be tested on the same data to correctly compare the performance of each allocation. The study showed that the heuristic using association rules gave the highest number of picks for the tested period. However, it was only marginally better than the method that first removed orders that could not be picked from the A-frame and then ranked all products by their quantities sold. The study's conclusion is that while association rule learning resulted in the highest number of picked orders, the gain of using it does not motivate its complexity. Instead a more simple approach by ranking products by their quantities sold should be used. Warehousing in the era of E-commerce has to be fast, correct and cheap.

This Master’s thesis is focused on the production system design, analysis material flow of the production system in the company ABC Ltd. Part of it is detection of critical places and proposal for their elimination. The theoretical part contains the basic concepts of production. In the analytical part, there is described a current situation in selected manufacturing segment of company. In the final part, the solutions are designed to help improve the business.

The purpose of the master thesis has been to examine the production system at the company Lundqvist Trävaru AB and use the gathered information to create a layout suggestion together with a couple of improvement ideas. The thesis is the final part of the Industrial Design Engineering programme at Luleå University of Technology (LTU). Lundqvist Trävaru AB is a manufacturing company that specializes in producing prefabricated building kits out of wood, but the insufficient size of their current factory located in the industrial area of Öjebyn on the outskirts of Piteå, have created a need to relocate to alarger site. This new site is located at Haraholmen south of Piteå. The aim and objective have therefore been to develop a layout suggestion as well as a couple of improvement ideas, with the purpose of solving the identified problems at the current factory, thereby making sure that they do not reappear at the new site. Methods in the form of interviews, observations and documentation reviews were performed to identify potential problems with the production system and the work organization. To aid the investigation of the current factory, literature reviews of scientific books and articles were also performed during the project, with the purpose of giving the thesis a solid scientific foundation. After an overview of the production system had been created, the next step was to analyze the identified problems. These affected many different aspects of the company, for instance the material handling, work organization, flow ofinformation, production flexibility, inventory capacity and production flow. The main problem that in turn caused many of the identified problems was the insufficient inventory capacity, which led to problems with overflowing inventories and long delivery times for materials. This in turn affected thematerial handling negatively and made it hard to keep track of materials in the factory.  Additional problems that were identified was divided workstations, scattered areas for material storage, an increasing amount of special orders with dimension outside of the ordinary size range, a lack of standardized working methods and lack of communication between the office and the production team. After the problems had been identified, the next part of the project was dedicated to performing creative methods with the purpose of developing layout concepts as well as improvement ideas. The methods that were used to fulfill this task was brainstorming, mind map, requirement specification, proximity chart and workshop. After these methods had been performed the result was four layout concepts and several improvement ideas.  The next step was to evaluate the layouts and the ideas with the help of the requirements that had been specified together with the management at Lundqvist. The evaluations resulted in a final layout together with the most promising improvement ideas. These ideas were to standardized drawings and working methods, increase the work with creating manuals for the different stations and machines, adapt the workstations for special orders, purchase tablet computers for each workstation thereby allowing better information sharing and contact between the production team and the office, create a digital map of the factory, use markings and colors at inventories to facilitate identification of specific materials, better routines for the disposal of production waste and larger passages for trucks and wheel loaders. The result of the last part of the project was a 3D-model of the factory and the site, which showed the placement of the different machines, workstations and inventories used during the production of the prefabricated building kits. The benefits of the suggested layout and improvement ideas are bettermaterial handling, increased inventory capacity, better information sharing, standardized working methods and drawings, a straighter production flow and an increased production flexibility, which gives a better ability to produce special orders. If it turns out that it is hard to implement the layout at thepresent, the recommendation for Lundqvist Trävaru AB is to start with implementing the improvement ideas and then successively implement the layout. The suggested ideas and layout will make the company more prepared for the future and increase their ability to handle the planned productionincrease, while also making sure that they are able to better keep production deadlines, attract more customers and successfully establish themselves at Haraholmen. Which in turn will lead to reduced unemployment and increased tax revenue for Piteå municipality / Syftet med examensarbete har varit att undersöka produktionssystemet hos företaget Lundqvist Trävaru AB, samt använda den insamlade informationen för att skapa ett layoutförslag tillsammans med ett par förbättringsidéer. Detta examensarbete är sista delen av programmet Teknisk Design vid Luleå Tekniska Universitet (LTU). Lundqvist Trävaru AB är ett tillverkningsföretag som är specialiserade på att producera prefabricerade byggsatser gjorda av trä, men otillräckligt utrymme vid deras nuvarandefabriken belagd i industriområdet Öjebyn i utkanten av Piteå, har skapat ett behov av att flytta till en större anläggning. Denna nya anläggning är placerad i Haraholmen söder om Piteå. Syftet och målet har därför varit att utveckla ett layoutförslag, såväl som ett antal förbättringsförslag, med syftet att lösa de identifierade problemen vid den nuvarande fabriken och därmed se till att de inte dyker upp igen vid den nya anläggningen. Metoder i form av intervjuer, observationer och dokumentgranskningar utfördes för att identifiera potentiella problem med produktionssystemet och arbetsorganisationen. För att underlätta undersökningen av den nuvarande fabriken utfördes också litteraturgranskningar av vetenskapliga böcker och artiklar under projektets gång, i syfte att ge examensarbetet en stabil vetenskaplig grund. Efter att en översikt av produktionssystemet hade skapats var nästa steg att analysera de identifierade problemen, vilket påverkade många olika aspekter av företaget, bland annat materialhanteringen, arbetsorganisationen, informationsflödet, produktionsflexibiliteten, lagerkapaciteten och produktionsflödet. Huvudproblemet som i sin tur orsakade många av de identifierade problemen, var den otillräckliga lagerkapaciteten, som lede till problem med överfyllda lager och långa leveranstider för material. Detta påverkade i sin tur materialhanteringen negativt och gjorde det svårt att hålla reda på material i fabriken. Ytterligare problem som identifierades var uppdelade arbetsstationer, utspridda områden för materiallagring, en ökande mängd specialbeställningar med dimensioner utanför det vanliga storleksområdet, brist på standardiserade arbetsmetoder samt brist på kommunikation mellan kontoret och produktionsteamet. Efter att problemen hade identifierats ägnades nästa del av projektet åt att utföra kreativa metoder i syfte att utveckla layoutkoncept och förbättringsidéer. Metoderna som användes föratt utföra denna uppgift var brainstorming, mind map, kravspecifikation, närhetsanalys och workshop. Efter att dessa metoder hade utförts blev resultatet fyra layoutkoncept och flera förbättringsidéer. Nästa steg var att utvärdera layouterna och idéerna med hjälp av de krav som hade specificerats tillsammans med ledningen hos Lundqvist. Utvärderingen resulterade i en slutlig layout tillsammans med de mest lovande förbättringsidéerna. Dessa idéer var att standardisera ritningar och arbetsmetoder, öka arbetet med att skapa manualer för de olika stationerna och maskinerna, anpassa arbetsstationerna för specialbeställningar, köpa surfplattor för varje arbetsstation och därmed möjliggör bättre informationsdelning och kontakt mellan produktionsteamet och kontoret, skapa en digital karta över fabriken, använda markeringar och färger vid lager för att underlätta identifiering av specifikt material, bättre rutiner för hantering av produktionsavfall och större passager för truckar och traktorer. Resultatet av projektets sista del var en 3D-modell av fabriken och tomten, som visade placeringen av de olika maskinerna, arbetsstationerna och lagren som används under produktionen av de prefabricerade byggsatserna. Fördelarna med den förslagna layouten och förbättringsidéerna är bättre materialhantering, ökad lagerkapacitet, bättre informationsdelning, standardiserade arbetsmetoder och ritningar, ett rakare produktionsflöde samt ökad produktionsflexibilitet, vilket ger en bättre förmåga att producera specialbeställningar. Om det visar sig vara svårt att implementera layouten i nuläget är rekommendationen för Lundqvist Trävaru AB att börja med att implementera förbättringsidéerna och sedan succesivt implementera layouten. De förslagna idéerna samt layouten kommer att göra företaget mer förberett för framtiden och öka deras förmåga att hantera den planerade produktionsökningen, samtidigt som de ser till att de kan hålla produktionsdeadlines bättre, locka fler kunder och framgångsrikt etablera sig på Haraholmen. Vilket i sin tur kommer att leda till minskad arbetslöshet och ökade skatteintäkter för Piteå kommun.

Im Kern der vorliegenden Arbeit wird eine neue Vorfahrtstrategie zur Steuerung von Materialflüssen an Zusammenführungen vorgestellt. Das Hauptanwendungsgebiet stellen innerbetriebliche Transportsysteme dar, wobei die Erkenntnisse auf beliebige Transport- bzw. Bediensysteme übertragbar sind. Die Arbeit grenzt sich mit der Annahme autokorrelierter Ankunftsprozesse von bisheriger Forschung und Entwicklung ab. Bis dato werden stets unkorrelierte Ströme angenommen bzw. findet keine spezielle Beachtung autokorrelierter Ströme bei der Vorfahrtsteuerung statt. Untersuchungen zeigen aber, dass zum einen mit hoher Konfidenz mit autokorrelierten Materialflüssen zu rechnen ist und in diesem Fall zum anderen von einem erheblichen Einfluss auf die Systemleistung ausgegangen werden muss. Zusammengefasst konnten im Rahmen der vorliegenden Arbeit 68 Realdatensätze verschiedener Unternehmen untersucht werden, mit dem Ergebnis, dass ca. 95% der Materialflüsse Autokorrelation aufweisen. Ferner wird hergeleitet, dass Autokorrelation intrinsisch in Materialflusssystemen entsteht. Die Folgen autokorrelierter Prozesse bestehen dabei in längeren Durchlaufzeiten, einem volatileren Systemverhalten und höheren Wahrscheinlichkeiten von Systemblockaden. Um die genannten Effekte an Zusammenführungen zu eliminieren, stellt die Arbeit eine neue Vorfahrtstrategie HAFI – Highest Autocorrelated First vor. Diese priorisiert die Ankunftsprozesse anhand deren Autokorrelation. Konkret wird die Vorfahrt zunächst so lange nach dem Prinzip First Come First Served gewährt, bis richtungsweise eine spezifische Warteschlangenlänge überschritten wird. Der jeweilige Wert ergibt sich aus der Höhe der Autokorrelation der Ankunftsprozesse. Vorfahrt bekommt der Strom mit der höchsten Überschreitung seines Grenzwertes. Die Arbeit stellt ferner eine Heuristik DyDeT zur automatischen Bestimmung und dynamischen Anpassung der Grenzwerte vor. Mit einer Simulationsstudie wird gezeigt, dass HAFI mit Anwendung von DyDeT die Vorzüge der etablierten Vorfahrtstrategien First Come First Served und Longest Queue First vereint. Dabei wird auch deutlich, dass die zwei letztgenannten Strategien den besonderen Herausforderungen autokorrelierter Ankunftsprozesse nicht gerecht werden. Bei einer Anwendung von HAFI zur Vorfahrtsteuerung können Durchlaufzeiten und Warteschlangenlängen auf dem Niveau von First Come First Served erreicht werden, wobei dieses ca. 10% unter dem von Longest Queue First liegt. Gleichzeitig ermöglicht HAFI, im Gegensatz zu First Come First Served, eine ähnlich gute Lastbalancierung wie Longest Queue First. Die Ergebnisse stellen sich robust gegenüber Änderungen der Auslastung sowie der Höhe der Autokorrelation dar. Gleichzeitig sind die Erkenntnisse unabhängig der Analyse einer isolierten Zusammenführung und der Anordnung mehrerer Zusammenführungen in einem Netzwerk.:1 Einleitung 1 1.1 Motivation 1 1.2 Zielsetzung, wissenschaftlicher Beitrag 4 1.3 Konzeption 5 2 Grundlagen 7 2.1 Automatisierung, Steuern, Regeln 7 2.2 System, Modell 10 2.3 Stochastik, Statistik 14 2.3.1 Wahrscheinlichkeitsverteilungen 14 2.3.2 Zufallszahlengeneratoren 21 2.3.3 Autokorrelation als Ähnlichkeits- bzw. Abhängigkeitsmaß 24 2.4 Simulation 29 2.5 Warteschlangentheorie und -modelle 32 2.6 Materialflusssystem 35 2.7 Materialflusssteuerung 37 2.7.1 Steuerungssysteme 37 2.7.2 Steuerungsstrategien 40 2.8 Materialflusssystem charakterisierende Kennzahlen 46 3 Stand der Forschung und Technik 51 3.1 Erzeugung autokorrelierter Zufallszahlen 51 3.1.1 Autoregressive Prozesse nach der Box-Jenkins-Methode 52 3.1.2 Distorsions-Methoden 54 3.1.3 Copulae 56 3.1.4 Markovian Arrival Processes 58 3.1.5 Autoregressive Prozesse mit beliebiger Randverteilung 61 3.1.6 Weitere Verfahren 64 3.1.7 Bewertung der Verfahren und Werkzeuge zur Generierung 65 3.2 Wirken von Autokorrelation in Bediensystemen 68 3.3 Fallstudien über Autokorrelation in logistischen Systemen 75 3.4 Ursachen von Autokorrelation in logistischen Systemen 89 3.5 Steuerung von Ankunftsprozessen an Zusammenführungen 96 3.6 Steuerung autokorrelierter Ankunftsprozesse 100 4 Steuerung autokorrelierter Ankunftsprozesse an Zusammenführungen 105 4.1 Modellannahmen, Methodenauswahl, Vorbetrachtungen 106 4.2 First Come First Served und Longest Queue First 114 4.3 Highest Autocorrelated First 117 4.3.1 Grundprinzip 117 4.3.2 Bestimmung der Grenzwerte 127 4.3.3 Dynamische Bestimmung der Grenzwerte mittels „DyDeT“ 133 4.4 Highest Autocorrelated First in Netzwerken 150 4.5 Abschließende Bewertung und Diskussion 161 5 Zusammenfassung und Ausblick 167 Primärliteratur 172 Normen und Standards 194 Abbildungsverzeichnis 197 Tabellenverzeichnis 199 Pseudocodeverzeichnis 201 Abkürzungsverzeichnis 203 Symbolverzeichnis 205 Erklärung an Eides statt 209 / The work at hand presents a novel strategy to control arrival processes at merges. The main fields of application are intralogistics transport systems. Nevertheless, the findings can be adapted to any queuing system. In contrast to further research and development the thesis assumes autocorrelated arrival processes. Up until now, arrivals are usually assumed to be uncorrelated and there are no special treatments for autocorrelated arrivals in the context of merge controlling. However, surveys show with high reliability the existence of autocorrelated arrivals, resulting in some major impacts on the systems\' performance. In detail, 68 real-world datasets of different companies have been tested in the scope of this work, and in 95% of the cases arrival processes significantly show autocorrelations. Furthermore, the research shows that autocorrelation comes from the system itself. As a direct consequence it was observed that there were longer cycle times, more volatile system behavior, and a higher likelihood of deadlocks. In order to eliminate these effects at merges, this thesis introduces a new priority rule called HAFI-Highest Autocorrelated First. It assesses the arrivals\' priority in accordance to their autocorrelation. More concretely, priority initially is given in accordance to the First Come First Served scheme as long as specific direction-wise queue lengths are not exceeded. The particular thresholds are determined by the arrival processes\' autocorrelation, wherein the process with the highest volume gets priority. Furthermore, the thesis introduces a heuristic to automatically and dynamically determine the specific thresholds of HAFI-so called DyDeT. With a simulation study it can be shown that HAFI in connection with DyDeT, combines the advantages of the well-established priority rules First Come First Served and Longest Queue First. It also becomes obvious that the latter ones are not able to deal with the challenges of autocorrelated arrival processes. By applying HAFI cycling times and mean queue lengths on the level of First Come First Served can be achieved. These are about 10% lower than for Longest Queue First. Concomitantly and in contrast to First Come First Served, HAFI also shows well balanced queues like Longest Queue First. The results are robust against different levels of throughput and autocorrelation, respectively. Furthermore, the findings are independent from analyzing a single instance of a merge or several merges in a network.:1 Einleitung 1 1.1 Motivation 1 1.2 Zielsetzung, wissenschaftlicher Beitrag 4 1.3 Konzeption 5 2 Grundlagen 7 2.1 Automatisierung, Steuern, Regeln 7 2.2 System, Modell 10 2.3 Stochastik, Statistik 14 2.3.1 Wahrscheinlichkeitsverteilungen 14 2.3.2 Zufallszahlengeneratoren 21 2.3.3 Autokorrelation als Ähnlichkeits- bzw. Abhängigkeitsmaß 24 2.4 Simulation 29 2.5 Warteschlangentheorie und -modelle 32 2.6 Materialflusssystem 35 2.7 Materialflusssteuerung 37 2.7.1 Steuerungssysteme 37 2.7.2 Steuerungsstrategien 40 2.8 Materialflusssystem charakterisierende Kennzahlen 46 3 Stand der Forschung und Technik 51 3.1 Erzeugung autokorrelierter Zufallszahlen 51 3.1.1 Autoregressive Prozesse nach der Box-Jenkins-Methode 52 3.1.2 Distorsions-Methoden 54 3.1.3 Copulae 56 3.1.4 Markovian Arrival Processes 58 3.1.5 Autoregressive Prozesse mit beliebiger Randverteilung 61 3.1.6 Weitere Verfahren 64 3.1.7 Bewertung der Verfahren und Werkzeuge zur Generierung 65 3.2 Wirken von Autokorrelation in Bediensystemen 68 3.3 Fallstudien über Autokorrelation in logistischen Systemen 75 3.4 Ursachen von Autokorrelation in logistischen Systemen 89 3.5 Steuerung von Ankunftsprozessen an Zusammenführungen 96 3.6 Steuerung autokorrelierter Ankunftsprozesse 100 4 Steuerung autokorrelierter Ankunftsprozesse an Zusammenführungen 105 4.1 Modellannahmen, Methodenauswahl, Vorbetrachtungen 106 4.2 First Come First Served und Longest Queue First 114 4.3 Highest Autocorrelated First 117 4.3.1 Grundprinzip 117 4.3.2 Bestimmung der Grenzwerte 127 4.3.3 Dynamische Bestimmung der Grenzwerte mittels „DyDeT“ 133 4.4 Highest Autocorrelated First in Netzwerken 150 4.5 Abschließende Bewertung und Diskussion 161 5 Zusammenfassung und Ausblick 167 Primärliteratur 172 Normen und Standards 194 Abbildungsverzeichnis 197 Tabellenverzeichnis 199 Pseudocodeverzeichnis 201 Abkürzungsverzeichnis 203 Symbolverzeichnis 205 Erklärung an Eides statt 209

Purpose – The purpose of this study is to increase the knowledge about the material handling of a module house manufacturing company. In order to achieve the study's purpose, three research questions were formulated. ▪ Which factors affect material handling? ▪ Which factors are considered important for material handling? ▪ How can standardization improve material handling? Method – The study has been characterized by an inductive approach to conducting the case study. To achieve the purpose, empirical data has been collected via a pilot study, interviews, observations, and document studies from reality. Subsequently, previous theories were examined via a literature collection. Furthermore, the processing and analysis of collected empirics and theory have helped to answer the purpose and demonstrate the generalizability of the study. Findings – The study has focused on the entirety of the various processes and an understanding of the various factors that influence material handling has been obtained. The case study company has challenges to look at the entirety of the modular house production and separates the production and construction sites. The wastes transport, movement, waiting and unused skills are considered to be the most important wastes to reduce or eliminate. It is clear that the case study company’s new employees must constantly reinvent the wheel and learn from their own mistakes. Moreover, it is difficult to determine if the mistake is a deviation, error or insufficient knowledge. By implementing a standard for what should be on drawings and how materials are to be delivered from production to the construction sites, deviations and wastes can be reduced and costs reduced. Implications – The study is based on a problem area that already exists in separate theories and comparisons. However, operations that have a material handling that both concerns manufacturing and construction work have not previously been investigated to the same extent, which is the theoretical contribution of the study. The empirical contribution to the study is to identify which factors affect material handling in businesses that have common flows between manufacturing and construction work. Limitations – The study only addresses two of the material handling flows; the material flow and the information flow. The study also does not take into account the processes of suppliers, subcontractors, or customers. Finally, the study will not include financial calculations to demonstrate potential cost efficiencies. Keywords – Material handling, Lean, Construction logistics, Wastes, Current flow, Value stream mapping, Lean tools.

Byggsektorn har fortfarande svårigheter med att hantera fuktproblematiken.  Vi har valt att fokusera på hanteringen av material i produktion. Den informationssamling vi utfört ligger till grund för vår analys och slutsats. Vi har intervjuat flera olika entreprenörer från byggbranschen för att ge oss en helhetssyn av fuktsäkerheten ute på byggarbetsplatserna. Studien påvisar att det råder brister både på beställar- och entreprenörssidan. Vi ser att det finns potential för förbättring när det så krävs. Därför rekommenderar vi att högre krav ställs på fuktsäkerheten och att tydliga riktlinjer finns att följa. Den handbok som framtagits är riktat till att hjälpa yrkesarbetarna på entreprenörssidan att uppnå de krav som ställs. Handboken innehåller tillvägagångssätt för materialhantering och fuktkvotsmätning samt kritiska fuktvärden för olika material. / The construction sector still has difficulties in dealing with moisture problems. We have chosen to focus on the material handling in the production phase at the building site. The information collection we performed is the basis for our analysis and conclusion. We have interviewed several contractors in the construction industry to give us a comprehensive view of the moisture safety out on construction sites. The study shows that there are shortcomings on both constructor- and contractor’s side. We see that there is a potential for improvement when it’s required. We recommend that greater demands are placed on the moisture safety and that clear guidelines are to follow. The handbook is directed at helping skilled workers in the contractor end to achieve the required demands. The handbook includes procedures for material handling and moisture measurements as well as critical moisture values for different materials.