The operators working the emergency line 112 receive, evaluate and handle information about the type of incidence while performing their job. They also receive situations where they handle emergency calls dealing with suicides. Talking to a person with suicidal intent is an extremely stressful and mentally challenging situation. Operators are well aware when handling a suicide call a human life hangs in the balance. They are the ones which can discourage the intention of suicide or lose the caller. Due to the seriousness of the matter it is really essential that the operators are professionally prepared to handle such calls and successfully deal with this challenging situation. The thesis deals with the handling of suicide calls on the single European emergency line 112 in the South Bohemia and Plzen regions. I established two goals for the diploma thesis. The first objective is to compare the professional preparation of the emergency line 112 operators for handling suicide calls in the South Bohemia and Plzen regions. The second is to create a proposal for increasing the training preparedness of the emergency line 112 operators for dealing with suicide calls. The thesis is divided into a theoretical and practical part. The theoretic part covers the basic concepts of the topic of suicide. In general the reader becomes familiar with the basic concepts, such as forms, motives, causes, developmental stages, methods or risk factors for suicidal tendencies, past and present social attitudes and other facts are described. Further the issue of crisis intervention is clarified from the point of view of the emergency call 112 centers and their operators. The theoretical part of the thesis relies on the knowledge based on the analysis, synthesis and research from available sources dealing with this issue. Printed books, magazines, journals, laws, statutory regulations and methodology of the Czech Republic Fire and Rescue Service, Fighting rule of Fire protection units, Catalog File of Type Activities and electronic sources were used as references. To achieve the purpose and obtain answers to the research question, the qualitative methodology of research was used in the thesis. In both regions, on the basis of a questionnaire survey, readiness of the emergency number 112 operators to handle calls from individuals contemplating suicide was evaluated and the research question answered. Response to the research question proved that professional preparedness of the operators of emergency number 112 for handling calls related to suicide requires the operators possess additional professional knowledge and skills. Based on the data from the questionnaire survey and a study of the professional literature, design methodology is developed to enhance professional preparation service emergency number 112 suicide calls. The results from the questionnaire survey indicated that not all the operators demonstrated the same knowledge level and skills and that regularly all of them do not go through the same training on the theme of suicide. Therefore in design methodology, training divided by each category is incorporated. For each category, a schedule, structure and content of the training is elaborated and a suitable trainer is recommended. In the discussion and conclusion of this thesis there are further useful recommendations listed which relate to the research topic, however they are not part of the above mentioned methodology.

The aim of the thesis is to propose applicable recommendations of the remuneration system, which will lead to higher customer satisfaction and employee engagement contact centres in order to reduce their turnover rate, which currently stands at 23 %. The methods used to achieved the objective analysis of the current remuneration system, guided interview with the head of contact centre survey. Based on the data obtained and the results were evaluated concrete proposals formulated so that it can be applied in practice. Recommendations relating to the adaptation of financial evaluation of call centre staff, changes in employee benefits, adjustments to the evaluation system, as well as changes in management personnel in managerial positions and proposals for the introduction of the cafeteria system in the company. In the context of applicability into account individual recommendations and cost perspective.

Dissertação (mestrado) - Universidade Federal de Santa Catarina, Centro Tecnológico, Programa de Pós-Graduação em Ciência da Computação, Florianópolis, 2013. / Made available in DSpace on 2013-12-05T22:55:16Z (GMT). No. of bitstreams: 1 319167.pdf: 2575562 bytes, checksum: e44fb321772f80bd9ae0b46533fa3c5d (MD5) Previous issue date: 2013 / Os algoritmos de previsão de chamadas em centrais de atendimento conseguem apresentar resultados aceitáveis diante de uma série de dados longa e bem comportada. Uma série de dados com essas características raramente é encontrada, o que restringe o uso dos algoritmos de previsão. Além disso, a falta de unidade das séries implica na presença de fenômenos que perturbam os dados. Esses fenômenos fazem com que o uso de métodos empíricos se multiplique dentre os membros das equipes de planejamento.O trabalho propõe um método de previsão de chamadas recebidas utilizando redes bayesianas para o tratamento desses fenômenos que perturbam de sobremaneira os dados. Com a proposta, é possível incorporar o conhecimento acerca desses fenômenos em um modelo de previsão computacionalmente eficiente.Para elaborar um método de previsão de chamadas em centrais de atendimento, algumas ferramentas precisaram ser desenvolvidas durante a elaboração do modelo. Primeiramente, foi necessário resolver a dificuldade da obtenção de dados de centrais de atendimento para o estudo do comportamento das chamadas recebidas. Foi então criado um simulador de call center onde é possível gerar dados de chamadas para serem utilizados nos modelos de previsão de chamadas. Em seguida, para o melhor entendimento dos algoritmos de previsão de dados, uma ferramenta de previsão por suavização exponencial foi criada como suplemento do Microsoft Excel. Por fim, foi proposto um método de previsão que utiliza as redes bayesianas para tratar os fatores aleatórios.As redes bayesianas se mostram uma boa alternativa para tratar a aleatoriedade presente nos fatores aleatórios. Os resultados obtidos mostram que o tratamento se faz necessário para a diminuição dos erros de previsão em centrais de atendimento. O modelo apresentado não requer grandes conhecimentos matemáticos por parte das equipes de planejamento, o que estimula o uso desse tipo de formalização. <br> / Abstract : The forecasting calls algorithms in contact centers can provide acceptable results before a long and well behaved time series dataset. However a time series with such characteristics is rarely found, which restricts the use of forecasting algorithms. Moreover, the lack of unity of these series implies the presence of some phenomena which disturb the data series. These phenomena make the use of empirical methods to multiply among the members of the planning team. This paper proposes a method of forecasting incoming calls using bayesian networks for the treatment of such phenomena which disturb the data. With this proposal, it is possible to incorporate the knowledge of these phenomena in a computationally efficient forecasting model. To develop a forecasting calls model in call centers, some tools needed to be developed during the elaboration of the forecasting model. First, to deal with the difficulty of obtaining data records from call centers to study the behavior of incoming calls. A simulated call center was developed, where it is possible to generate call data for use in forecasting models of calls. Then, for better understanding of data prediction algorithms, a forecasting tool for exponential smoothing was created as a supplement to Microsoft Excel. Finally, it was proposed a forecasting model that uses bayesian networks to deal with the random factors. Bayesian networks are shown as a good alternative for treating the randomness present in random factors. The results show that the treatment is necessary to reduce the forecasting errors in call centers. The model presented does not require great mathematical knowledge by planning teams, which encourages the use of this kind of formalization.

Dissertação (mestrado) - Universidade Federal de Santa Catarina, Centro Tecnológico, Programa de Pós-Graduação em Engenharia de Produção. / Made available in DSpace on 2012-10-19T08:16:08Z (GMT). No. of bitstreams: 0Bitstream added on 2013-07-16T18:40:38Z : No. of bitstreams: 1 178888.pdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) / A presente pesquisa teve como objetivo a caracterização da situação de trabalho no âmbito da organização das atividades desenvolvidas por uma equipe de líderes de um Call Center e/ou Central de Atendimento de uma operadora de telecomunicações brasileira. O estudo realizado constituiu-se de uma tentativa de diagnosticar a organização do trabalho dessa equipe frente a um momento de reestruturação intensa, quando há apenas dois anos, passou pelo processo de privatização da empresa e se deparou com a necessidade de quebra de paradigmas e consequentemente, mudança de comportamento originada pelas novas tendências do mercado de telecomunicações. A pesquisa, que aconteceu entre os meses de fevereiro e dezembro do ano de 2000, é do tipo exploratória-descritiva-avaliativa e procurou combinar aspectos da dimensão objetiva e subjetiva. O método estudo de caso está fundamentado na análise intensiva de uma única organização, denominada ficticiamente de Alfa. Trinta e cinco indivíduos que exerciam as funções do cargo de Supervisor no segmento Serviços Básicos do Call Center da Alfa em Florianópolis formaram a amostra. A coleta de dados deu-se por meio de questionário elaborado pela Beta Telemarketing e validado num estudo semelhante realizado em outro Call Center da empresa em outro estado. Além dessa, as técnicas de entrevista, análise documental e a observação também foram utilizadas. A partir da coleta de dados, os mesmos foram objeto de análise comparativa de acordo com o que foi inicialmente proposto, o que fez pressupor significativas mudanças na organização do trabalho dessa equipe estratégica e nos seus padrões culturais, objetivando práticas de trabalho mais eficazes e modelos de gestão voltados para um desenvolvimento contínuo das pessoas e da organização / Abstract The present research had as great objective the characterization of the situation of work in the scope of the organization òf the activities developed by a team of leaders of a brazilian telecommunications call centers company. The carried through study one consisted of an attempt to diagnosis the organization of the work of this team by a moment of intense reorganization, when just two years ago, it passed for the process of privatization of the company and if it came across with the necessity of paradigm in addition and change of behavior originated for the new trends of the market of telecom. The research happened between February and December - 2000 and looked for to match aspects of the objective and subjective dimension. The method case study is based on the intensive analysis of an only organization. Thirty five individuals that exerted the functions of the position of Supervisor in Serviços Básicos Alfa's Call Center in Florianópolis had formed the sample. The information was collected given by a questionary elaborated by Beta Telemarketing^and validated in a carried through similar study in another Alias's Call Center in another state. Beyond this, the techniques of interview, documentary analysis and the comment had been also used. From the collection of informations, the same people had been object of comparative analysis in accordance with what initially it was considered, what made to estimate significant changes in the organization of the work of this strategical team and in its cultural standards, looking for practical of work more efficient and models of management to a continuous development of the people and the organization.

Contact Centre agents operate in closely monitored and highly controlled environments and their work consists of solving service requests or assisting customers with information on products or services. Consequently their work involves a great deal of emotional labour and stress. It is not surprising then, that the working environment of the Contact Centre is reported to have a negative impact on the levels of Quality of Worklife of Contact Centre agents, and that in the Contact Centre context, it is likely that low levels of Quality of Worklife exist. It is argued that it is important for organisations to be particularly aware of the Quality of Worklife perceptions of their employees should they want to address Quality of Worklife levels and benefit from the positive consequences of higher levels of the construct. Numerous variables are reported to play either an antecedent, moderating, mediating, or consequential role in relation to the Quality of Worklife construct. A systems model of Quality of Worklife is developed, which illustrates the inter-relationships of these variables and how they affect and are affected by the Quality of Worklife construct. It is argued that leadership is an important antecedent to Quality of Worklife, and this is the antecedent of interest in this study. It is proposed that it is not just any leadership that will contribute to an improved Quality of Worklife, particularly within a challenging context such as the Contact Centre environment. Rather, it is suggested that certain qualities of leaders will have a greater influence on Quality of Worklife. For example, leaders who focus on relationships and are caring - characteristics associated with servant leaders - are deemed more suitable for the Contact Centre context. The research also proposes that there are close associations between Servant Leadership and Trust, which in turn has the potential to affect Quality of Worklife positively. It is argued, therefore, that Trust mediates the relationship between Servant Leadership and Quality of Worklife in the customer service frontline context. While there is a broad base of literature available on servant leadership that focuses on the senior or executive level of leadership, Van Dierendonck and Nuijten (2011) have argued that it is also relevant at the middle level of management and have validated an eight dimensional measure of servant leadership that is suitable for this management level. The Van Laar, Edwards and Easton (2007) Quality of Worklife model is also argued to be an appropriate model and measure of the Quality of Worklife construct, due to the robustness of the instrument design and the appropriateness of its underlying theory to the context of this research. Research has shown that leadership can have a significant relationship with Quality of Worklife. Moreover, a review of the literature on servant leadership reveals that trust, satisfaction, general well-being, and commitment to their jobs increases when employees are exposed to leadership behaviours associated with servant leadership. There is however, no evidence in the literature of any investigation of the relationship between Servant Leadership and Quality of Worklife, or of research investigating the partial mediating effects of Trust between these two constructs. Research was conducted to test this relationship. A survey questionnaire was administered amongst a sample of 555 Contact Centre agents, who were employed in eight different organisations. Confirmatory factor analysis procedures were conducted in STATA (V15.0), to test and validate the factor structure of Servant Leadership and Quality of Worklife models. The research also produced a Servant Leadership, Trust and Quality of Worklife structural equation model that supported the hypotheses of the relationships between the constructs. Mediation analysis confirmed Trust’s role as a mediator between Servant Leadership and Quality of Worklife. The structural equation model confirmed that synergies between Servant Leadership, Trust and Quality of Worklife exist, and that Trust partially mediates the relationship between Servant Leadership and Quality of Worklife. It is therefore argued that an increase in Servant Leadership behaviour by the manager or supervisor of frontline staff has a positive association with increases of Trust, as well as positive associations with Quality of Worklife experienced by employees in the frontline context. Moreover, it is also posited that the relationship between Servant Leadership and Quality of Worklife is partially mediated by Trust of the supervisor. The implications of these results are discussed, and recommendations made for management practice and further research.

Thesis (MTech (Business Administration))--Cape Peninsula University of Technology, 2009. / This study provides a comprehensive overview of challenges and obstacles that are caused by high telecommunications costs within the callcentre industry in Cape Town, South Africa. This study couldn't have come at a better time considering the current turbulent economic circumstances around the world. The study focuses on key areas such as, growth, profitability, employment creation and sustainability of callcentres. In order to fulfil research requirements, primary data was collected by using a quantitative data collection approach in the form of questionnaires and interviews. Results indicate that the biggest obstacle to growth within the callcentre industry in the Western Cape, is high telecommunications costs. The study recommends that our Government should intervene through its communications departments as means to reduce current telecommunications costs. Callcentres should also explore use of new telecommunications technology, namely VoIP. A solution to the high telecommunications costs will not only benefit the callcentre industry but the entire country through foreign direct investments, job creation and poverty alleviation. This will result into true empowerment of our society.

Este trabalho apresenta CivisAnalysis, uma aplicação web de código aberto para visualização das votações ocorridas na Câmara dos Deputados do Brasil. Com dados abrangendo seis legislaturas e seis eleições presidenciais, CivisAnalysis provê uma visão inovadora da história política do Congresso Brasileiro combinando técnicas clássicas de visualização de votações e técnicas de apresentação de dados temporais. As votações de cada deputado podem ser interpretadas como dados multidimensionais e são representadas em um espectro n-dimensional mapeado para uma representação bidimensional. Os votos de cada deputado determinam suas posições numa representação conhecida como espectro político. O trabalho mostra como a exploração de conjuntos de Deputados permite a descoberta de padrões de votos no espectro de votações, assim como explorar conjuntos de votações permite a descoberta de padrões de comportamento no espectro de Deputados. Para uma análise política de longo termo, foi criada uma linha do tempo apresentando as distâncias relativas dos partidos no espectro político durante seis legislaturas e eleições presidenciais. Na linha de tempo é possível perceber os alinhamentos políticos e mudanças comportamentais de partidos conforme o progresso de legislaturas, alianças eleitorais e coalizões de governo. A interface de CivisAnalysis oferece filtros textuais e visuais e inclui visualizações auxiliares para destacar cenários políticos de acordo com Deputados, partidos, unidades federativas, alianças eleitorais e suas posições no espectro político. / In this work, we present CivisAnalysis, an open-source web-based system for the visualization of roll calls in the Brazil’s Chamber of Deputies. Using roll calls of six legislatures as well as six presidential elections, CivisAnalysis provides a unique view of the political history of our country. It combines classical roll calls visualization techniques with techniques for the visualization of temporal data. Votes of each representative are interpreted as a set of multidimensional data, which are represented in a n-dimensional space mapped to a bi-dimensional representation. The Votes of each representative determine their position in the political spectrum of deputies, and the votes of all deputies determine the political spectrum of roll calls. The work also shows how exploring subsets of deputies allows the discovery of voting patterns in the roll call spectrum, as well as exploring the roll calls spectrum allows the discovery of behavioral voting patterns in the political spectrum of deputies. For supporting a long-term political analysis, CivisAnalysis provides a time line visualization integrated with election data (election results and political alliances). The tool implements textual and visual filtering and includes auxiliary visualizations that provide an overview of the political scenario regarding deputies, parties, coalitions and their behavior along time.

Evolução de software é uma das atividades mais desafiadoras do processo de desenvolvimento de software. Uma importante questão associada à essa atividade é a correta compreensão do código fonte e outros artefatos que necessitam ser mantidos e evoluídos. Visando auxiliar desenvolvedores na manutenção de código, Integrated Development Environments (IDE’s) proporcionam ferramentas que informam desenvolvedores sobre as dependências e as particularidades do código a ser modificado. No entanto, linguagens dinamicamente tipadas não definem tipos explicitamente no código fonte, o que dificulta a análise estática do código e consequentemente a contrução dessas ferramentas. Como exemplo, a construção de call graphs (grafos de chamadas), utilizados pelas IDE’s para criar ferramentas de navegação de código, é prejudicada pela ausência da definição de tipos. Para abordar o problema da criação de call graphs para linguagens dinamicamente tipadas, propomos uma técnica dividida em passos para a construção de um call graph baseado em informações extraídas da execução de testes. A técnica é dividida em 3 passos, o Passo #1 cria um call graph conservativo e estático que resolve chamadas de métodos baseado apenas em nomes dos métodos, ainda no primeiro passo, testes são executados e seu traço de execução é armazenado para posterior análise. O Passo #2 combina a informação armazenada da execução dos testes e o call graph construído no primeiro passo, o Passo #2 também é responsável pela criação de um conjunto de regras de associação que servirão para guiar desenvolvedores durante a criação de novas partes do código. Nossa avaliação em uma aplicação real de porte grande mostrou que a técnica melhora a precisão do call graph criado removendo arestas desnecessárias (70%), e mostrou-se apta a auxiliar desenvolvedores definindo pontos de navegação no código baseada na análise de regras de associação extraídas do test-case-based call graph. / Evolving enterprise software systems is one of the most challenging activities of the software development process. An important issue associated with this activity is to properly comprehend the source code and other software assets that must be evolved. To assist developers on these evolution tasks, Integrated Development Environments (IDEs) build tools that provides information about the source code and its dependencies. However, dynamically typed languages do not define types explicitly in the source code, which difficult source code analysis and therefore the construction of these tools. As an example, the call graph construction, used by IDE’s to build source code navigation tools, is hampered by the absence of type definition. To address the problem of constructing call graphs for dynamic languages, we propose a technique based on steps to build a call graph based on test runtime information, called test-case-based call graph. The technique is divided in three steps; Step #1 creates a conservative and static call graph that decides target nodes based on method names, and the first step also run tests profiling its execution; Step #2 combines the test runtime information and the conservative call graph built in the first step to create the test-case-based call graph, it also creates a set of association rules to guide developers in the maintenance while creating new pieces of code; Finally, Step #3 uses the test-case-based call graph and the association rules to assist developers in source code navigation tasks. Our evaluation on a large-size real-world software shows that the technique increases call graph precision removing several unnecessary conservative edges ( %70), and assist developers filtering target nodes of method calls based on association rules extracted from the call graph.

O Risco Operacional nas instituições financeiras foi normatizado com a Resolução nº 3.380 em 29 de junho de 2006, emitida pelo Conselho Monetário Nacional. Desde então, entidades autorizadas a funcionar pelo Banco Central do Brasil tiveram de adequar suas estruturas e procedimentos com o intuito de aumentar os controles sobre eventos internos e externos à instituição, com a finalidade de reduzir perdas financeiras a partir da mitigação deste tipo de risco. Dessa forma, a presente dissertação tem como objetivo apresentar como um banco comercial precisa agir para adequar seus processos às novas exigências legais diante de um assunto com uma importância tão significativa. Este trabalho, além de apresentar os procedimentos de gestão de riscos em uma entidade, procura também elucidar como o risco operacional, no departamento de Call Center da instituição financeira escolhida, pode afetá-la, no caso da inobservância dos procedimentos a serem adotados com vistas à mitigação das falhas já identificadas e de possíveis ocorrências que possam comprometer a continuidade da organização. Os resultados obtidos na pesquisa mostram que o banco em estudo, em relação a outras instituições financeiras pesquisadas, ainda apresenta-se em uma etapa de desenvolvimento da sua área de gestão de riscos, trabalhando em conformidade com a legislação vigente e buscando aperfeiçoar suas técnicas de identificação e mensuração dos riscos operacionais. / Operational risk in financial institutions was normalized with Resolution No. 3380 on June 29, 2006, issued by the National Monetary Council. Since then, entities authorized to operate by the Central Bank of Brazil had to adapt its structures and procedures in order to tighten controls on internal and external events to the institution, in order to reduce financial losses from this type of risk mitigation. Thus, this paper aims to present as a commercial bank must act to adjust its processes to the new legal requirements before a subject with a very significant importance. This paper, besides presenting the procedures for managing risks in an entity, also seeks to clarify how operational risk, the department's Call Center financial institution chosen may affect it, in the case of a failure of procedures to be adopted in order mitigating the flaws already identified and possible events that could endanger the continuity of the organization. The results obtained from the survey show that the bank under study in relation to other financial institutions surveyed, still comes in a stage of development of their area of risk management, working in accordance with current legislation and seeking to improve their techniques identification and measurement of operational risks.

Au cours des dernières années, les centres d'appels ont été introduits avec succès par de nombreuses entreprises axées sur les services comme les banques et les compagnies d'assurance. Ils deviennent le principal point de contact avec les clients, et une partie intégrante de la majorité des sociétés. L'émergence à grande échelle des centres d'appels a créé une source féconde de problèmes de gestion des opérations. Dans cette thèse, nous nous concentrons sur la question de dimensionnement et définition des emplois du temps dans les centres d'appels. L'objectif de notre travail consiste à développer des analyses qualitatives ainsi que quantitatives, afin de déduire des recommandations utiles aux managers.Nous analysons quatre problèmes qui tiennent compte de l'incertitude sur les paramètres d'arrivée des appels. Le processus d'arrivée des appels est supposé suivre un processus non stationnaire et doublement stochastique avec un taux moyen d'arrivée aléatoire.Dans le premier modèle, nous considérons un centre d’appels avec une seule vacation possible. Les agents traitent en même temps des appels entrants et des tâches de back-office. Ceci permet d’avoir une certaine souplesse pour modifier en temps réel la capacité instantanée de traitement des appels entrants. Nous analysons l'impact de la flexibilité offerte par les charges de travail de back-office.Dans le deuxième modèle, nous considérons un centre d'appels avec plusieurs vacations possibles. Les agents traitent seulement des appels entrants. Dans ce modèle, le dimensionnement initialement établi peut être corrigé au cours de la journée de travail. Nous proposons une approche de programmation stochastique en deux étapes et une approche de programmation réglable robuste pour résoudre le problème d’optimisation. En particulier, nous analysons et montrons l'avantage supplémentaire d'utiliser le réglage dynamique sur les coûts de dimensionnement du centre d’appels. Dans le troisième modèle, nous considérons un autre type d'incertitude supplémentaire, qui est l'incertitude sur la distribution de probabilité d'un paramètre aléatoire. Nous proposons une approche combinant la programmation stochastique et la programmation distributionnellement robuste, et nous évaluons son rendement. Le dernier problème de dimensionnement d’un centre d'appels pour lequel le manager se propose de satisfaire un niveau de service global pour toute la journée au lieu d’un niveau de service objectif par période. Nous permettons également la mise à jour du dimensionnement au cours de la journée. Dans notre analyse, nous montrons en particulier les avantages de l'ajout de la flexibilité de mise à jour, et soulignons l'impact d'avoir une contrainte de service niveau globale sur les performances. / In the past few years, call centers have been introduced with great success by many service-oriented companies such as banks and insurance companies. They become the main point of contact with the customers, and an integral part of the majority of corporations. The large-scale emergence of call centers has created a fertile source of management issues. In this thesis, we focus on the issue of staffing and scheduling of call centers. The objective of our work is to derive both qualitative and quantitative results for practical management.We specifically address the analysis of four problems that take into account the important feature of uncertainty in the call arrival parameters. The call arrival process is assumed to follow a doubly non-stationary stochastic process with a random mean arrival rate.In the first model, we consider a single-shift call center blending inbound calls and back-office jobs. By allowing the possibility of real-time changes in the capacity dealing with inbound calls, we analyze the impact of the flexibility offered by back-office jobs.In the second model, we consider a multi-shift call center with single type of inbound calls, in which the scheduling update is allowed. We propose a two-stage stochastic programming approach and an adjustable robust programming approach to efficiently solve the problem. We also analyze the benefits of using dynamic adjustment on scheduling.In the third model, we consider an additional type of uncertainty, namely the uncertainty on the probability distribution of a random parameter. We propose an approach combining stochastic programming and distributionally robust programming, and evaluate its performance.The last model deals with a call center optimization under a global service level constraint instead of period by period constraints. We again allow scheduling decisions to be updated during the middle of the day. We show the advantages of adding the update flexibility, and point out the impact of having a global service level constraint on performance