Tidigare hade Husmuttern problem med att styra lagernivåer och inköpsorder, detta påverkade negativt på produktionen. Företaget hade inget effektivt system för att utföra planering och styra lagernivåer. Styrning av material och lagernivå utförs utifrån externa leverantörer. Transporten av råmaterial har planerats till varannan dag utan att ta hänsyn till fordonens uppfyllnadsnivå eller hur det påverkar transportkostnad och miljö. Syftet med examenarbetet är att identifiera problem och ge rekommendationer med stöd av teorier om hur ett effektivt materialplaneringssystem kan genomföras, för att öka lönsamhet, minska transportkostnad, miljöpåverkan samt uppnå balans mellan materialflöde och efterfrågan. Resultaten visade att genom att använda ett effektivt materialplaneringssystem, styrs både lagernivå och inköpsorder. Studenten testade även att använda beställningspunktsmetod för att styra lagernivå och inköpsorder. / Previously, Husmuttern had difficulty controlling inventory levels and purchase orders. This had a negative impact on production. The company had no effective system to plan and control inventory levels; material and inventory management was performed by an external supplier. The transport of raw materials was planned every other day and failed to take into account the vehicle’s load capacity, it has affected transport costs and the environment. The purpose of the thesis work is to identify problems and provide recommendations, supported by theories of how an efficient material planning system can be implemented, to increase profitability, reduce transport costs, environmental impacts, as well as achieve balance between material flow and demand. The results showed that using an effective material planning system, both stock levels and purchase orders are controlled. The student tested using the order point method to control stock levels and purchase orders.

Traffic congestion increases travel times, but also results in higher energy usage and vehicular emissions. To evaluate the impact of traffic emissions on environment and human health, the accurate estimation of their rates and location is required. Traffic emission models can be used for estimating emissions, providing emission factors in grams per vehicle and kilometre. Emission factors are defined for specific traffic situations, and traffic data is necessary in order to determine these traffic situations along a traffic network. The required traffic data, which consists of average speed and flow, can be obtained either from traffic models or sensor measurements. In large urban areas, the collection of cross-sectional data from stationary sensors is a costefficient method of deriving traffic data for emission modelling. However, the traditional approaches of extrapolating this data in time and space may not accurately capture the variations of the traffic variables when congestion is high, affecting the emission estimation. Static transportation planning models, commonly used for the evaluation of infrastructure investments and policy changes, constitute an alternative efficient method of estimating the traffic data. Nevertheless, their static nature may result in an inaccurate estimation of dynamic traffic variables, such as the location of congestion, having a direct impact on emission estimation. Congestion is strongly correlated with increased emission rates, and since emissions have location specific effects, the location of congestion becomes a crucial aspect. Therefore, the derivation of traffic data for emission modelling usually relies on the simplified, traditional approaches. The aim of this thesis is to identify, quantify and finally reduce the potential errors that these traditional approaches introduce in an emission estimation analysis. According to our main findings, traditional approaches may be sufficient for analysing pollutants with global effects such as CO2, or for large-scale emission modelling applications such as emission inventories. However, for more temporally and spatially sensitive applications, such as dispersion and exposure modelling, a more detailed approach is needed. In case of cross-sectional measurements, we suggest and evaluate the use of a more detailed, but computationally more expensive, data extrapolation approach. Additionally, considering the inabilities of static models, we propose and evaluate the post-processing of their results, by applying quasi-dynamic network loading.

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I och med människornas ökade livslängd har kraven på sjukvården ökat, samtidigt finns det en bristande tillgång på vårdpersonal. Genom att öka antalet arbetsuppgifter för sjukvårdspersonalen som är värdeskapande för patienten kan sjukvården svara på kraven, då sjukvårdens befintliga resurser kan användas på ett mer effektivt sätt. Utifrån observationer och tidmätningar som har utförts på Vrinnevisjukhusets vårdavdelning (AVD1) för stroke och rehabilitering av stroke, har detta examensarbete kunnat ge förslag på förbättringsområden som kan effektivisera och öka antalet värdeskapande arbetsuppgifter för läkarna och sjuksköterskorna. Utifrån tidmätningarna skapades även en tidfördelning av läkarnas respektive sjuksköterskornas arbetsuppgifter på AVD1, och visade att en läkare och sjuksköterska på AVD1 spenderade mest tid på administrativa arbetsuppgifter (48 % för läkare och 26 % för sjuksköterskor), kommunikation (15 % för läkare och 24 % för sjuksköterskor) patienttid (15 % för läkare och 20 % för sjuksköterskor). De största förbättringsområdena av både läkarnas och sjuksköterskornas arbetsuppgifter som identifierades utifrån observationerna och resultatet av tidfördelning var att bristen på riktlinjer för införandet av journalanteckningarna ineffektiviserade deras administrativa arbetsuppgifter, samt att saknaden av ett system för läkemedelssaldo försvårade sjuksköterskornas läkemedelshantering. För att åtgärda problemen bör AVD1 och hela medicinkliniken som AVD1 ingår i, fastställa riktlinjer för hur inskrivning av information i journal skall genomföras för att undvika dubbelarbete och underlätta informationssökningen. Medicinkliniken bör även investera i ett nytt lagersystem som uppdaterar saldot för läkemedel automatiskt, där det också går att utläsa hur mycket av varje läkemedel som finns på respektive avdelning och i respektive lager. Övriga förbättringsområden som identifierades för läkarna och sjuksköterskorna på AVD1 var att placeringen av utrustning och verktyg på AVD1 kan förbättras med hjälp av Leans 5S, samt att genom planering och tydligöring att rapportering pågår kan läkare och sjuksköterskor minska på sysslolöshet och antalet gånger de blir avbrutna under en arbetsuppgift. AVD1 skulle även kunna öka en läkares respektive sjuksköterskas värdeskapande arbetsuppgifter genom att uppdatera datorerna, samt omplacera eller investera i fler skrivare och telemetridatorer. / With people’s increased life span, the demand for health care services has increased, while there is a lack of health care professionals. By increasing the health care professionals’ value-adding work assignments for patient care, they will be used more efficiently and be able to meet the demand of the health care services. Based on observations and time studies carried out at Vrinnevisjukhusets health care facility for stroke and rehabilitation of stroke, this thesis has provided suggestions for areas of improvement which could increase the amount of doctors’ and nurses’ value-adding work assignments. Based on the result time studies at the health care facility, a time distribution of the doctors’ and nurses’ work assignments was also established and showed that they spent their most time on administrative work (48 % for doctors and 26 % for nurses), communication (15 % for doctors and 24 % for nurses) and time with patient (15 % for doctors and 20 % for nurses). Based on the observations and the result of time distribution, the doctors and nurses main areas of improvement was the lack of guidelines for implementation of journal notes which made their administrative work assignments inefficient, as well as the lack of system for the stock levels of medicines, which hindered the nurses’ medication management. To address these problems the health care facility and the entire medical clinic that the facility is part of, should determine guidelines on how the journal notes should be conducted for avoidance of duplications and to also facilitate the search of information. The medical clinic should also invest in a new storage system which updates the stock levels of medicines automatically, and also makes it possible to see how much of each medicine is available in each facility and storage. The arrangement of the facilities storage is also an area that could be improved by implementing the Leans’ 5S, which would improve the doctors’ and nurses’ time distribution and increase the value-adding work assignments. By also planning and clarify when a reporting is ongoing, as well as relocate or invest in more printers and telemetry computers, the facilities doctors’ and nurses’ time distribution will be improved and also increase the amount of work assignments that is value-adding.

Infrastructure managers in railway systems are striving to have as efficient track utilization as possible. There are no unanimous interpretation of efficiency in terms of track utilization, but the aim of the Swedish Transport Administration is to allocate track capacity such that societal benefit is maximized. This means that the tracks should be used by as much traffic as possible and by traffic that provides as much benefit for the society as possible. To allocate track capacity such that the track utilization is optimal would be an easy task if the track capacity were not a scarce resource. Today, many train operators share railway network and there are cases when two or more operators want to use the same track capacity at the same time. The infrastructure manager must then make priorities and reject some operators, and the question is which operators to reject. The guiding principle is to grant the operators that provide the highest societal benefit access to the tracks. However, the question would then change into how to know which operator that provides the highest societal benefit. In this thesis, the societal benefit of publicly subsidized traffic is estimated using social cost-benefit analysis. Mathematical models and methods are developed for quantifying and computing the number of departures for the publicly subsidized traffic and their distribution in time, i.e. a train timetable, that provides the maximal societal benefit in a social cost-benefit analysis setting. The societal benefit of commercial traffic is estimated using the market value for their requested train timetables. The market value is set using dynamic pricing. A suggestion of a dynamic pricing process that can be used in the train timetabling process is described. Mathematical models and methods for calculating the supply and demand of a track access request are developed and tested, which enables the use of a dynamic pricing process on track capacity

The trend of more advanced driver-assistance features and the development toward autonomous vehicles enable new possibilities in the area of active safety. With more information available in the vehicle about the surrounding traffic and the road ahead, there is the possibility of improved active-safety systems that make use of this information for stability control in safety-critical maneuvers. Such a system could adaptively make a trade-off between controlling the longitudinal, lateral, and rotational dynamics of the vehicle in such a way that the risk of collision is minimized. To support this development, the main aim of this licentiate thesis is to provide new insights into the optimal behavior for autonomous vehicles in safety-critical situations. The knowledge gained have the potential to be used in future vehicle control systems, which can perform maneuvers at-the-limit of vehicle capabilities. Stability control of a vehicle in autonomous safety-critical at-the-limit maneuvers is analyzed by the use of optimal control. Since analytical solutions of the studied optimal control problems are intractable, they are discretized and solved numerically. A formulation of an optimization criterion depending on a single interpolation parameter is introduced, which results in a continuous family of optimal coordinated steering and braking patterns. This formulation provides several new insights into the relation between different braking patterns for vehicles in at-the-limit maneuvers. The braking patterns bridge the gap between optimal lane-keeping control and optimal yaw control, and have the potential to be used for future active-safety systems that can adapt the level of braking to the situation at hand. A new illustration named attainable force volumes is introduced, which effectively shows how the trajectory of a vehicle maneuver relates to the attainable forces over the duration of the maneuver. It is shown that the optimal behavior develops on the boundary surface of the attainable force volume. Applied to lane-keeping control, this indicates a set of control principles similar to those analytically obtained for friction-limited particle models in earlier research, but is shown to result in vehicle behavior close to the globally optimal solution also for more complex models and scenarios.

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