Seja {Xn} uma sequência de variáveis aleatórias i.i.d. assumindo valores num alfabeto enumerável. Dada uma coleção de palavras finita, observamos esta sequência até o momento τ em que uma dessas palavras apareça em X1, X2, .....Neste trabalho utilizamos a abordagem de martingais, introduzida por Li (1980) e Gerber e Li (1981), para estudar o tempo de espera até que uma das palavras ocorra pela primeira vez, o tempo médio de τ e a probabilidade de uma palavra ser a primeira a aparecer. / Let {Xn} be a sequence of i.i.d. random variables talking values in an enumerable alphgabet. Given a finite collection of words, we observe this sequence till the moment τ at which one of these words appears as a run. In this work we apply the martingale approach introduced by Li (1980) and Gerber and Li (1981) in order to study the waiting time until one of the words occurs for the first time, the mean of τ and the probability of a word to be first on to appear.

O presente estudo tem como principal objetivo avaliar o impacto de aspectos contingenciais no modelo básico do efeito da espera na avaliação geral de um serviço. Com base em estudos referentes à espera já realizados, o presente trabalho definiu o “modelo básico do efeito da espera na avaliação geral do serviço” que consiste no impacto negativo da espera na avaliação geral do serviço por meio da suscitação de emoções negativas. A influência de fatores contingenciais sobre o modelo é a principal contribuição do estudo, dado que essa abordagem não havia sido ainda estudada. Inicialmente, foi realizada uma etapa exploratória, qualitativa, para investigar as relações propostas no modelo teórico, assim como para compreender melhor os serviços de saúde, campo de estudo da pesquisa. Na sequência, a influência do envolvimento do consumidor, da singularidade do serviço, da pressão do tempo e do relacionamento interpessoal no modelo central foi investigada através da realização de uma survey com 382 pacientes As hipóteses foram testadas por meio de modelagem de equações estruturais, com o software LISREL 8.51. Os resultados indicam que o envolvimento do consumidor tem impacto positivo no seu tempo de espera aceitável. Já o efeito da singularidade do serviço sobre essa mesma variável não foi confirmado. A pressão do tempo apresentou impacto positivo no tempo de espera percebido e o efeito moderador do relacionamento interpessoal na relação entre as respostas afetivas negativas e a avaliação geral do serviço também foi confirmada. Além das hipóteses propostas, foi realizado um teste exploratório segundo o qual se confirmou o efeito moderador da variável gravidade sobre as relações que compõe o modelo básico do efeito da espera da avaliação geral do serviço. No final, os resultados são discutidos, e as limitações do estudo e sugestões para futuras pesquisas são apresentadas. / The most important objective of the present study is to evaluate the impact of the contingency aspects on the basic model of the waiting effect in the overall service evaluation. Based on studies in reference to the wait already carried out, this study defined the "basic model of the waiting effect on the general evaluation of the service" as being the negative impact of waiting in the general evaluation of the service because of the rise of negative emotions. The influence of contingency factors over the model is the most important contribution of the study as this approach has never been studied before. Iniatially, there was a qualitative exploratory to investigate the proposed relations in the theoretical model, as well as to have a better understanding of health care services, the field study of the research. Following that, the influence of the consumer involvement, the uniqueness of the service, the time pressure and the interpersonal relationship in the central model was investigated through a survey conducted among 382 patients The hypotheses were tested using structural equation modeling with LISREL 8.51 software. The results showed that the consumer involvement have a positive impact in the acceptable waiting time. On the other hand the effect of the uniqueness of the service over the same variable was not confirmed. The time pressure indicated a positive impact on the perceived waiting time and the moderate effect of the interpersonal relationship of the connection between negative affective reactions and the overall service evaluation was also confirmed. Beyond the proposed hypotheses, it was performed a exploratory test whereby it was confirmed the moderator effect of the gravity variable on the relations that form the basic model of the waiting effect on the overall service evaluation. In the end the results are discussed, and the limitations of the study and suggestions for future surveys are presented.

<p>The development and provision of equitable and acceptable standard of health services to all segments of the population has been the major objective of the 1993 Ethiopian National health policy. However, community based studies on satisfaction with public health care facilities reveal that the majority of the population are not satisfied with the services provided predominantly as a result of the long waiting times. Studies done on private health facilities on the contrary reveal that patients are satisfied with the service delivered within short waiting times in these clinics. Even though the speculated waiting time is thought to be long among the public health care facilities and short in private clinics, the actual waiting and service times have not been measured and compared. Aim: To determine the waiting and service times among the public and private health care facilities and measure the perceptions of &ldquo / acceptable&rdquo / waiting time among the providers and clients. Materials and methods: A cross sectional observational study using quantitative techniques was carried out amongst patients and staff at selected public and private health care facilities in Gondar District. Stratified sampling method was used to select facilities. All patients visiting the selected facilities and all staff who provided service to patients on the day of the study were included in the time-delimited sample. Data was collected by research assistants and health workers from all patients attending the health care facility by registering the arrival and departure time of each patient to the facility and to each service point on a patient flow card. Then data was cleaned and captured by a specific Waiting and Service Time database. Descriptive statistics was done on waiting and service times for each facility and this was summarized for each public and private health facility by using tables and graphs. Finally a comparison was made for private and public health facilities by using Wilcoxon-mann-whitney non parametric tests.</p>

Logistics plays a crucial role in companies’ ability to sustain competitive on the market. Time is regarded as one of the important metric in terms of logistics, since time influences the lead time of the products, which results in the vital advantage of speed. The recent business environment forces Kinnarps Production AB, a manufacturer of furniture, to optimize their inventory material flow in a way of increasing their capability and capacity to load more distribution containers with goods daily. The present circumstances of the material flow are associated with number of negative factors. An automated guided vehicle (AGV) system is operating and handling the distribution of goods. Wrong sequence of activities, long transportations, high transportation delays, waiting time, varying numbers of AGVs, wastes, bottlenecks are among the important issues to be considered. The purpose of this thesis is to analyze the material flow in Kinnarps Production AB’s inventory seven and to improve the AGV system activities within. Concepts associated with identifying waste were used by separating value-adding activities from the non-value added ones. The usage of ideal reference systems techniques were the base for identifying problems. Concrete literature regarding AGV’s design system was applied in establishing different statements about the material flow and identification of problems. Different methods and techniques were used in approaching the research, but most above others is the case study approach. Numerous amounts of secondary data have been employed in verifying the collection of other data carried out by primary data collection as well as verifying the qualitative and quantitative analysis. A mapping of the current system was established with respect to orders, times and distances. Numbers of congestion points were identified, non-value adding activities were eliminated or decreased, rearrangement of sequencing of different activities was considered and different pallets arrangement system was established. A stochastic model was used in identifying the AGV’s time variables in the system and estimating appropriate amount of AGVs within the inventory. All the findings from different calculations and estimations were associated with Kinnarps Production’s future increased demand. Different issues and considerations were analyzed and appropriate suggestions were given for elimination of the negative factors in the inventory or their decrease. Among the most influencing results was the proper amount of AGVs in the inventory area, pallets rearrangement, different stocking policy, rearrangement in the sequence of activities, increase of the buffer for pallets used for loading containers, new conveyor system for the incoming goods in the inventory, transportation layout changes resulting in blocking free routines, separate control system, decrease of the effect of stoppages. All these findings are considered to optimize the material flow and increase the system capacity contributing to an increase of the daily containers outgoing from Kinnarps Production AB.

<p>Logistics plays a crucial role in companies’ ability to sustain competitive on the market. Time is regarded as one of the important metric in terms of logistics, since time influences the lead time of the products, which results in the vital advantage of speed. The recent business environment forces Kinnarps Production AB, a manufacturer of furniture, to optimize their inventory material flow in a way of increasing their capability and capacity to load more distribution containers with goods daily. The present circumstances of the material flow are associated with number of negative factors. An automated guided vehicle (AGV) system is operating and handling the distribution of goods. Wrong sequence of activities, long transportations, high transportation delays, waiting time, varying numbers of AGVs, wastes, bottlenecks are among the important issues to be considered.</p><p>The purpose of this thesis is to analyze the material flow in Kinnarps Production AB’s inventory seven and to improve the AGV system activities within.</p><p>Concepts associated with identifying waste were used by separating value-adding activities from the non-value added ones. The usage of ideal reference systems techniques were the base for identifying problems. Concrete literature regarding AGV’s design system was applied in establishing different statements about the material flow and identification of problems. Different methods and techniques were used in approaching the research, but most above others is the case study approach. Numerous amounts of secondary data have been employed in verifying the collection of other data carried out by primary data collection as well as verifying the qualitative and quantitative analysis.</p><p>A mapping of the current system was established with respect to orders, times and distances. Numbers of congestion points were identified, non-value adding activities were eliminated or decreased, rearrangement of sequencing of different activities was considered and different pallets arrangement system was established. A stochastic model was used in identifying the AGV’s time variables in the system and estimating appropriate amount of AGVs within the inventory.</p><p>All the findings from different calculations and estimations were associated with Kinnarps Production’s future increased demand. Different issues and considerations were analyzed and appropriate suggestions were given for elimination of the negative factors in the inventory or their decrease. Among the most influencing results was the proper amount of AGVs in the inventory area, pallets rearrangement, different stocking policy, rearrangement in the sequence of activities, increase of the buffer for pallets used for loading containers, new conveyor system for the incoming goods in the inventory, transportation layout changes resulting in blocking free routines, separate control system, decrease of the effect of stoppages. All these findings are considered to optimize the material flow and increase the system capacity contributing to an increase of the daily containers outgoing from Kinnarps Production AB.</p>

Amusement parks are a huge business. Guest experiences determine the success or failure for an amusement park. This report suggests an approach to improve guest experience by managing guest flow. The guest happiness optimization problem is formulated into a visitor routing management model. The constraints for this model include attraction attributes and guest behavior. To build the attraction constraints, their information is first gathered from internet, field studies and surveys, and then input into simulation software. Constraints on guest behavior are set up with a literature study and a guest survey. A two phase heuristic is developed to solve this problem with constraints. Candidate routes are generated with a route construction algorithm in the first phase. Visitor distribution and selection on these candidate routes are determined in the second phase using a mixed integer programming solver. Visitor routes are then recommended to the park’s operator side, for them to distribute to guests visiting on their vacations. Data from Disney Epcot are collected and applied in the case study to implement the methodology in this report. Attraction operations capability is maintained at the current level with no additional cost for the project, while guest satisfaction is improved by ensuring the number and type of attractions they visit. In addition, average waiting time for visitors is reduced by at least 70% in the recommended operation strategy. / text

In a constantly increasing and more demanding global market, companies must continuously improve and develop in order to stay competitive. A manufacturing company can have several goals in order to succeed in this, both strategically and internally within the production. Unfortunately, many goals conflict with each other due to the interrelationship between them. Decisions must be taken whether to focus on maximizing delivery precision, minimizing costs of tied-up capital, or minimizing production costs, which means that trade-offs are necessary to be made. At Gnutti Carlo Sweden in Alvesta, this is their present reality, where a completely new production line is currently being installed. This is planned to start producing in the beginning of 2016, with successively increased volumes until reaching full production in 2018. Due to process constraints, inventories must be placed within the process in order to keep these utilized to the highest extent possible. On one hand, sufficient inventory must be kept in order to prevent waiting time in the constraining work station, and on the other hand, inventories within the process should be kept as small as possible, this in order to minimize holding costs and required space. This conflict formed the purpose of the study, which was to achieve a suitable balance between minimizing waiting times in the constraining station and the level of inventories within the process, with main focus on waiting times. In order to fulfill the purpose, the problem was approached using simulation as the main methodology. In addition to simulation, the study included elements of case studies, experimental methods and action research, which were present at different stages of the project. A nine-step simulation methodology was the inspiration in how the study was conducted, which included necessary mile-stones for reaching qualitative simulation results from a real system, meaning that the approach had a high focus on validation. By creating a conceptual model, which is a reflection of the current state, a simulation model that represented the process was possible to create. By applying different aspects from existing philosophies and concepts, such as Lean production, Theory of Constraints, and other production concepts, it was possible to form a set of scenarios that corresponded to different potential approaches that were believed to fulfill the study purpose. Using the simulation model, several experiments were conducted, testing the effects from applying the different scenarios, which mainly consisted of different batching strategies to use in a non-constraining work station located prior to the inventory in the process. The results showed that using smaller batches of similar sizes in the non-constraining work station, prior to the supermarket, is significantly decreasing inventory levels, this while not negatively affecting the waiting time in the constraint. The results showed decreased inventories up to approximately 50% when testing certain scenarios, however not considering some parameters that may affect the process. Important to consider is that the excess capacity of the process is what is controlling the minimum size of the batches, thus also the inventory size needed. Recommendations included to use different batching strategies for non-constraining stations, as well as to further investigate the process before production start, as some parts of the process are excluded in the study. / I en ständigt växande och mer krävande global marknad måste företag kontinuerligt förbättras och utvecklas för att fortsatt vara konkurrenskraftiga. Ett tillverkningsföretag kan ha olika mål för att lyckas med detta, både strategiska och interna inom produktionen. Tyvärr verkar flera mål mot varandra på grund av ett inbördes förhållande. Beslut måste tas gällande att antingen fokusera på att maximera leveransprecisionen, minimera kostnaden för bundet kapital eller minimera produktionskostnaderna, vilket betyder att kompromisser måste tillämpas. På Gnutti Carlo Sweden i Alvesta är detta deras nuvarande verklighet, där en helt ny produktionslinje för närvarande installeras. Denna är planerad att börja producera i början av 2016, med succesivt ökande volymer fram tills 2018, då full produktion nås. På grund av processbegränsningar måste lager placeras i processen för att upprätthålla en högsta möjlig utnyttjandegrad för dessa. Å ena sidan måste tillräckliga lager hållas för att undvika väntetider i den begränsande arbetsstationen, å andra sidan bör lagernivåerna hållas så låga som möjligt, detta för att minimera lagerkostnader och lagerutrymme. Denna konflikt var grunden till syftet till studien, vilket var att uppnå en passande balans mellan minimering av väntetider i den begränsande arbetsstationen och lagernivåerna i processen, med huvudfokus på väntetider. För att kunna uppfylla syftet var problemet angripet med hjälp av simulering som huvudsaklig metod. Utöver simulering innehöll studien element av fallstudier, experimentella metoder och aktionsforskning, vilka var aktiva under olika faser av projektet. En nio steg lång simuleringsmetod tjänade som inspiration för hur studien genomfördes, vilken innefattade nödvändiga milstolpar för att lyckas nå kvalitativa simuleringsresultat från ett verkligt system, vilket innebar att metodiken fokuserade mycket på validering. Genom att skapa en konceptuell modell, vilket är en avspegling av nuläget, kunde en simuleringsmodell som representerade processen att skapas. Genom applicering av olika aspekter från existerande filosofier och koncept, exempelvis Lean production, Begränsningsteorin samt andra produktionskoncept, möjliggjordes bildandet av en samling scenarier som motsvarade olika, potentiella, tillvägagångssätt som ansågs kunna uppfylla studiens syfte. Genom simuleringsmodellen utfördes flera experiment, vilka testade effekterna från appliceringen av de olika scenarierna, som huvudsakligen bestod av olika strategier gällande partierna i en icke-begränsande arbetsstation, vilken är placerad innan lagret i processen. Resultatet visade att, genom applicering av mindre partistorlekar i den icke-begränsande arbetsstationen före lagret i processen, kan lagernivåerna minskas avsevärt, detta utan att negativt påverka väntetiderna i begränsningen. Resultatet visade minskade lager med upp till 50% för vissa scenarier, detta dock utan hänsyn tagen till vissa parametrar som kan påverka processen. Viktigt att beakta är att överskott av kapaciteten i processen är vad som kontrollerar minimistorleken på partierna, därför också lagerstorleken som krävs. Rekommendationerna innefattade införandet av olika strategier gällande partierna i icke-begränsande arbetsstationer samt att fortsatt undersöka processen, detta på grund av att vissa delar av processen är exkluderade i studien.

<p>The development and provision of equitable and acceptable standard of health services to all segments of the population has been the major objective of the 1993 Ethiopian National health policy. However, community based studies on satisfaction with public health care facilities reveal that the majority of the population are not satisfied with the services provided predominantly as a result of the long waiting times. Studies done on private health facilities on the contrary reveal that patients are satisfied with the service delivered within short waiting times in these clinics. Even though the speculated waiting time is thought to be long among the public health care facilities and short in private clinics, the actual waiting and service times have not been measured and compared. Aim: To determine the waiting and service times among the public and private health care facilities and measure the perceptions of &ldquo / acceptable&rdquo / waiting time among the providers and clients. Materials and methods: A cross sectional observational study using quantitative techniques was carried out amongst patients and staff at selected public and private health care facilities in Gondar District. Stratified sampling method was used to select facilities. All patients visiting the selected facilities and all staff who provided service to patients on the day of the study were included in the time-delimited sample. Data was collected by research assistants and health workers from all patients attending the health care facility by registering the arrival and departure time of each patient to the facility and to each service point on a patient flow card. Then data was cleaned and captured by a specific Waiting and Service Time database. Descriptive statistics was done on waiting and service times for each facility and this was summarized for each public and private health facility by using tables and graphs. Finally a comparison was made for private and public health facilities by using Wilcoxon-mann-whitney non parametric tests.</p>

Bakgrund: Antalet äldre patienter som söker vård till akutmottagningen har ökat med åren. De flesta sökande av dessa äldre patienter är multisjuka, vilket innebär att de äldre patienterna har minst två sjukdomar. Sjuksköterskor upplever stress och frustration i sitt arbete på akutmottagningen på grund av tidsbrist och brist i kompetenser samt erfarenhet. Syfte: Att beskriva äldre multisjuka patienters upplevelser av att bli vårdade på akutmottagningen. Metod: En systematisk litteraturstudie med beskrivande syntes baserad på 10 kvalitativa vetenskapliga artiklar. Resultat: Resultatdelen presenteras utifrån två teman med sina respektive subteman. Första temat är ”Positiva upplevelser”, som inkluderar två subteman” Att uppleva tillfredsställelse och bli sedd och respekterad” och ” Att uppleva trygghet och tillit”. Andra tema är ”Negativa upplevelser” som inkluderar två subteman ”Att uppleva sig övergiven” och ”Att uppleva brist på trygghet och tillit”. Slutsats: Äldre multisjuka patienter har en stark önskan om att uppleva trygghet och sjuksköterskans närvaro. Att sjukvårdspersonalen är professionella och säkra i sin yrkesroll leder till att äldre patienter känner sig trygga, sedda och respekterade. När sjukvårdspersonalen inte har tillräckliga kunskaper och erfarenheter om de äldre patienternas hälsotillstånd leder det till att de äldre patienterna upplevde sig övergivna, otrygga samt en minskad tillit till sjukvårdspersonalen. / Background: The number of older patients who require and seek the emergency department is increasing every year. Most of them have multiple diseases, which means that the older patients have at least two diseases. The nurses encounter a lot of stress and frustration while working at the emergency department because there is always shortage of time but also because they might have a lack in their knowledge, certain competence skills or experience. Aim: To describe the experiences of older patients with multiple diseases to be cared at the emergency department. Method: A systematic literature study with descriptive synthesis based on 10 qualitative scientific articles. Results: The result is presented based on two themes with two subthemes, respectively. The first theme is "Positive Experiences", which includes two subthemes "Experiencing satisfaction, being seen and respected" and "Experiencing security and trust". The second theme is "Negative Experiences", which includes two subthemes "Experiencing abandonment" and "Experiencing lack of security and trust". Conclusion: Older patients with multiple diseases have a strong desire for staff presence and safety. The fact that healthcare personnel are professional and safe in their occupational role leads to older patients feeling safe, seen and respected. When healthcare personnel do not have sufficient knowledge and experience about the older patients’ health condition, older patients experience abandonment, insecurity and reduced confidence in healthcare personnel.

O presente estudo tem como principal objetivo avaliar o impacto de aspectos contingenciais no modelo básico do efeito da espera na avaliação geral de um serviço. Com base em estudos referentes à espera já realizados, o presente trabalho definiu o “modelo básico do efeito da espera na avaliação geral do serviço” que consiste no impacto negativo da espera na avaliação geral do serviço por meio da suscitação de emoções negativas. A influência de fatores contingenciais sobre o modelo é a principal contribuição do estudo, dado que essa abordagem não havia sido ainda estudada. Inicialmente, foi realizada uma etapa exploratória, qualitativa, para investigar as relações propostas no modelo teórico, assim como para compreender melhor os serviços de saúde, campo de estudo da pesquisa. Na sequência, a influência do envolvimento do consumidor, da singularidade do serviço, da pressão do tempo e do relacionamento interpessoal no modelo central foi investigada através da realização de uma survey com 382 pacientes As hipóteses foram testadas por meio de modelagem de equações estruturais, com o software LISREL 8.51. Os resultados indicam que o envolvimento do consumidor tem impacto positivo no seu tempo de espera aceitável. Já o efeito da singularidade do serviço sobre essa mesma variável não foi confirmado. A pressão do tempo apresentou impacto positivo no tempo de espera percebido e o efeito moderador do relacionamento interpessoal na relação entre as respostas afetivas negativas e a avaliação geral do serviço também foi confirmada. Além das hipóteses propostas, foi realizado um teste exploratório segundo o qual se confirmou o efeito moderador da variável gravidade sobre as relações que compõe o modelo básico do efeito da espera da avaliação geral do serviço. No final, os resultados são discutidos, e as limitações do estudo e sugestões para futuras pesquisas são apresentadas. / The most important objective of the present study is to evaluate the impact of the contingency aspects on the basic model of the waiting effect in the overall service evaluation. Based on studies in reference to the wait already carried out, this study defined the "basic model of the waiting effect on the general evaluation of the service" as being the negative impact of waiting in the general evaluation of the service because of the rise of negative emotions. The influence of contingency factors over the model is the most important contribution of the study as this approach has never been studied before. Iniatially, there was a qualitative exploratory to investigate the proposed relations in the theoretical model, as well as to have a better understanding of health care services, the field study of the research. Following that, the influence of the consumer involvement, the uniqueness of the service, the time pressure and the interpersonal relationship in the central model was investigated through a survey conducted among 382 patients The hypotheses were tested using structural equation modeling with LISREL 8.51 software. The results showed that the consumer involvement have a positive impact in the acceptable waiting time. On the other hand the effect of the uniqueness of the service over the same variable was not confirmed. The time pressure indicated a positive impact on the perceived waiting time and the moderate effect of the interpersonal relationship of the connection between negative affective reactions and the overall service evaluation was also confirmed. Beyond the proposed hypotheses, it was performed a exploratory test whereby it was confirmed the moderator effect of the gravity variable on the relations that form the basic model of the waiting effect on the overall service evaluation. In the end the results are discussed, and the limitations of the study and suggestions for future surveys are presented.