The first chapter of this thesis is centered around a simple problem: to do or not to do something. As in life, every decision has an unknown outcome and planning agents try to balance the trade offs of such decision based on some relevant information. After processing the relevant information a decision is reached. In this chapter, the problem is formalized and parameterized in two frameworks: In the first framework discrete decision models known as decision trees are studied, where we design an optimization algorithm to solve the misclassification cost problem in this family of representations; The second framework studies continuously differentiable models (such as logistic regression and Deep Neural Networks) where we propose a two-step optimization procedure of the misclassification cost problem, as well as characterizing the statistical estimation problem relative to the sample size used for training. We illustrate the methodology by developing a computerized scheme to administer (or not) a preventive intervention to patients arriving to the hospital with the objective of minimizing their risk of acquiring a Hospital Acquired Infection (HAI). The second chapter expands on the idea of the first one to a sequential setting. The problem is framed as a Markov Decision Process algorithm using a state aggregation strategy based on Decision Trees. These incremental state aggregations are solved using a Linear Programming (LP) approach to obtain a compact policy that converges to the optimal one asymptotically, as well as showing that the computational complexity of our algorithm depends on the tree structure of the optimal policy rather than the cardinality of the state space. We illustrate the advantages of our approach using the widely known cartpole balancing environment against a Deep Neural Network based approach showing that with a similar computational complexity our algorithm performs better in certain instances of MDP. In the last two chapters we deal with modeling Emergency Medical Service (EMS) optimization such that the demand for medical services is met with the best possible supply allocation in the face of uncertainty of the demand in space and time. In the third chapter we develop a short-term prediction model for call volume at a 911 call center. The rationale of the model is to use the recent call volume to update a historically calibrated model of the call volume that in periods when the call volume distribution drastically changes, can be arbitrarily distant from its expected value. The model is casted as a linear correction of the historical estimation, calculating both the mean and variance of the correction. We justify the formulation using a regime switching doubly stochastic process framework to illustrate the type of distribution changes our model captures. We also propose a staffing model to preemptively staff a call center using our volume prediction as input for the call center demand such that the waiting times of the customers are minimized. This formulation can be casted as a Second Order Cone Program (SOCP) or a Linear Program (LP) with integrality constraints. We illustrate the methodology to predict the call volume during the Covid-19 pandemic to a 911 call center in New York City. In the fourth chapter we modify a well known set covering formulation to perform ambulance scheduling such that the supply of ambulances matches the demand in space and time. We enhance this model using a high resolution simulation model to correct an unknown steady-state service rate of the system (dependent on many exogenous and endogenous factors such as the ambulance dispatch policy and time-varying traffic patterns) as a constraint in the scheduling formulation. We show that this formulation effectively makes the system faster by maximizing the minimum slack between supply and demand during a 24-hour period. We present an algorithm to iteratively solve the scheduling formulation while correcting the implied location and time dependent service rate of the ambulance system using the simulation generated ambulance waiting times of patients in the city. We illustrate our algorithm to schedule municipally managed ambulances in New York City as a case study.

No description available.

The general aim of the research is to determine the relationship between personality traits as measured by the Customer Contact Styles Questionnaire (CCSQ 7.2) and work performance as measured by means of internal company data sources, of call centre agents. Recent literature indicates a significant relationship between personality traits and work performance. The emphasis in this research is on the factor analytical or trait approach of personality. The sample consisted of 300 call centre agents. The relationship between personality traits and work performance is discussed in terms of descriptive statistics, correlations and multiple regression analyses. The results indicate a relationship between the personality traits of analytical thinking, detail consciousness, conscientiousness, structuredness and work performance as measured by the level of financial incentives for call centre agents. This finding could be implemented in the selection and performance management of call centre agents. / Industrial & Organisational Psychology / M. Com. (Industrial Psychology)

The objective of the study was to determine whether any relationships exist between personality and the performance of sales staff in a call centre environment. Personality type (measured by the Jung Type Indicator [JTI]) and sales personality type (measured by the Sales Preference Indicator [SPI]) were correlated with sales staff performance in an insurance call centre environment. A quantitative survey was conducted using a sample of N = 146. Correlational and inferential statistical analyses revealed statistically significant positive, although weak, relationships between personality type and the performance of call centre sales staff while statistically significant positive and negative correlations, although weak, were found between sales personality type and the performance of call centre sales staff. More female and black sales staff members were found in the higher performing clusters than in the average and poorer performing clusters. The best subset of personality scales from the JTI that predicted univariate measures of performance were the extroversion-introversion scale and the judging-perceiving scale while the best subset of predictors from the SPI personality scale were the consistent-adaptive scale and the cooperative-competitive scale. Call centre performance criteria are based mainly on quantitative performance criteria. It emerged from the literature review that the call centre sales position is synonymous with emotional labour and it is, thus, recommended that future research should emphasise the importance of emotionally intensive labour and its measurement combined with quantitative performance measures. / Industrial & Organisational Psychology / M.A. (Industrial and Organisational Psychology)

Thesis (MBA (Business Management))--Stellenbosch University, 2008. / ENGLISH ABSTRACT: The primary objective of this study was to establish if the Adolescent/Adult Sensory Profile questionnaire (AASP) could be used as a recruitment tool in selecting contact centre agents with a higher predictability for success and hence higher productivity. Contact centres around the globe face the challenge of high staff turnover and absenteeism, reducing profitability. It seems that work performance related to the way in which adults process sensory input has not been well researched. A model was developed by Dunn (Brown et al., 2001) based on the intersection of a neurological threshold continuum and a behavioural continuum and yielding four quadrants: Quadrant 1, Low Registration (of stimuli); Quadrant 2, Sensation Seeking; Quadrant 3, Sensory Sensitivity, and Quadrant 4, Sensation Avoiding. Forty-eight contact centre agents employed by Liberty Life were selected and assessed on the AASP. Performance data for each contact centre agent were collected: available time, auxiliary time, log-in time, quality assurance, absenteeism and length of service. Spearman rank correlations were conducted to test if relationships exist between any of the four quadrants and the performance measures. As an additional investigation, a Suitability Score (based on clustering of scores with a percent assigned) was derived for each contact centre agent and also correlated with the above performance measures. Significant relationships were found between Quadrant 2 scores and three of the performance measurement criteria. As the Quadrant 2 scores increase, the average available time of the agents will decrease and their average log-in time will increase. Absenteeism increased as well, which is expected to have a negative effect on the productivity of the contact centre. The Quadrant also had a high predictability for Suitability Ratings indicating that as the Quadrant 2 score increases, the suitability of the contact centre agents increases as well. Regarding Quadrant 3 (sensory sensitivity) scores, quality assessment, total days of absenteeism and average absenteeism relate negatively. It seems that contact centre agents with high sensory sensitivity are less suitable for the job. As the score increases the quality assessment scores decrease, which is not what is required in terms of quality standards. A negative relationship exists between Quadrant 3 scores and the Suitability Rating scores, indicating that the higher the quadrant scores the less suitable the contact centre agents are to work in the contact centre environment. Quadrant 4 (sensation avoiding) has a negative relationship with Suitability Rating scores, which indicates that the higher the quadrant score the less suitable the contact centre agent is to work in the contact centre environment. No significant relationships were recorded between the performance measurements and Quadrant 1 (low registration) and Quadrant 4 (sensation avoiding), even though, logically, one would expect agents with less distraction to be more productive. Further studies are recommended before the Adolescent/Adult Sensory Profile questionnaire is used as a recruitment tool. Future studies could categorise the quadrant scores into clusters and then test for relationships with the set performance measurements. The Suitability Rating was used in a first attempt to match individuals in a specific job according to specific sensory profiles. This measure has not yet been tested for validity and reliability, which must be done prior to further study using it. / AFRIKAANSE OPSOMMING: Die primêre doel van hierdie studie was om vas te stel of die Adolescent/Adult Sensory Profile (AASP) vraelys gebruik kan word as ‘n hulpmiddel vir die werwing en seleksie van kontaksentrum agente, met ‘n hoër waarskynlikheid van sukses en, dus, hoër produktiwiteit. Kontaksentrums op elke vasteland kom te staan voor die probleem van hoë personeelomset en werksafwesigheid wat winsgewendheid verlaag. Die manier waardeur volwasse mense hul sensoriese insette verwerk, in verband met werkprestasie, is nog nie goed ondersoek nie. ‘n Model is deur Dunn (Brown et al., 2001) ontwikkel wat gebasseer is op die kruispunt van ‘n neurologiese drumpel kontinuum en ‘n gedragskontinuum wat tot vier kwadrante lei: Kwadrant 1, Lae Registrasie (van stimuli); Kwadrant 2, Sensasie Soekend; Kwadrant 3, Sensoriese Sensitiwiteit, en Kwadrant 4, Vermyding van Sensasie. Agt-en-veertig kontaksentrum agente wat in diens van Liberty Life is, is geselekteer en beoordeel volgens die AASP. Prestasiedata is saamgestel vir elke kontaksentrum agent: beskikbare tyd, oortollige tyd, teenwoordige tyd, kwaliteitsversekering, werksafwesigheid en jare diensplig. Spearman rang korrelasies is onderneem om te toets of daar verbande bestaan tussen enige van die vier kwadrante en die prestasiemaatstaf. In ‘n addisionele ondersoek is ‘n geskiktheidsmaatstaf ontwikkel wat gebasseer is op trosvorming van tellings met ‘n toegekende persentasie. Dit is gedoen vir elke kontaksentrum agent en hierdie tellings is ook gekorreleer met bogenoemde prestasiemaatstawwe. Statisties-beduidende positiewe verbande is gevind tussen Kwadrant 2 (sensasie soekend) tellings en drie van die prestasiemetingskriteria. As die telling van Kwadrant 2 toeneem, neem die gemiddelde beskikbare tyd af en die teenwoordige tyd van agente toe. Werksafwesigheid het ook toegeneem, wat moontlik negatief kan inwerk op die produktiwiteit van die kontaksentrum. Die kwadrant het ook ‘n hoë waarskynlikheid openbaar in die geval van die Gekiktheidsmaatstaf, wat aandui dat, namate die Kwadrant 2 telling toeneem, die gekiktheid van die kontaksentrum agent ook toeneem. Wat Kwadrant 3 (sensoriese sensitiwiteit) tellings betref, bestaan daar ‘n negatiewe verband tussen kwaliteitsversekering, totale aantal dae van werksafwesigheid en gemiddelde werksafwesigheid. Dit blyk dat kontaksentrum agente met hoë sensoriese sensitiwiteit dalk minder geskik is vir die pos. Soos wat die telling vir sensoriese sensitiwiteit toeneem, neem die telling vir kwaliteitsversekering af, wat nie in terme van kwaliteitstandaarde aanvaarbaar is nie. Daar bestaan ‘n negatiewe verband tussen Kwadrant 4 (sensasie vermyding) tellings en die tellings vir die Geskiktheidsmaatstaf, wat aandui dat hoe hoër die kwadrant telling, hoe minder geskik is die agent. Geen statisties-beduidende verbande is gevind tussen die prestasietellings van Kwadrant 1 (lae registrasie) en Kwadrant 4 (sensasie vermyding) nie. Normaalweg sou mens verwag dat agente met minder afleiding, meer produktief sou wees. Daar word voorgestel dat verdere studies onderneem word voordat die Adolescent/Adult Sensory Profile as ‘n werwingsmaatstaf gebruik word. Toekomstige studies kan die kwadrant tellings saamvoeg in trosse en dan toets vir verbande met die vooropgestelde prestasiemaatstawwe. Die Geskiktheidsmaatstaf is gebruik as ‘n eerste poging om individue saam te voeg in ‘n spesifieke pos, volgens ‘n spesifieke sensoriese profiel. Hierdie maatstaf moet vir toepaslikheid en betroubaarheid in verdere studie getoets word, voordat dit gebruik kan word.

The general aim of the research is to determine the relationship between personality traits as measured by the Customer Contact Styles Questionnaire (CCSQ 7.2) and work performance as measured by means of internal company data sources, of call centre agents. Recent literature indicates a significant relationship between personality traits and work performance. The emphasis in this research is on the factor analytical or trait approach of personality. The sample consisted of 300 call centre agents. The relationship between personality traits and work performance is discussed in terms of descriptive statistics, correlations and multiple regression analyses. The results indicate a relationship between the personality traits of analytical thinking, detail consciousness, conscientiousness, structuredness and work performance as measured by the level of financial incentives for call centre agents. This finding could be implemented in the selection and performance management of call centre agents. / Industrial and Organisational Psychology / M. Com. (Industrial Psychology)

The objective of the study was to determine whether any relationships exist between personality and the performance of sales staff in a call centre environment. Personality type (measured by the Jung Type Indicator [JTI]) and sales personality type (measured by the Sales Preference Indicator [SPI]) were correlated with sales staff performance in an insurance call centre environment. A quantitative survey was conducted using a sample of N = 146. Correlational and inferential statistical analyses revealed statistically significant positive, although weak, relationships between personality type and the performance of call centre sales staff while statistically significant positive and negative correlations, although weak, were found between sales personality type and the performance of call centre sales staff. More female and black sales staff members were found in the higher performing clusters than in the average and poorer performing clusters. The best subset of personality scales from the JTI that predicted univariate measures of performance were the extroversion-introversion scale and the judging-perceiving scale while the best subset of predictors from the SPI personality scale were the consistent-adaptive scale and the cooperative-competitive scale. Call centre performance criteria are based mainly on quantitative performance criteria. It emerged from the literature review that the call centre sales position is synonymous with emotional labour and it is, thus, recommended that future research should emphasise the importance of emotionally intensive labour and its measurement combined with quantitative performance measures. / Industrial and Organisational Psychology / M.A. (Industrial and Organisational Psychology)

Thesis (MA (Industrial Psychology))--University of Stellenbosch, 2006. / In the new service economy organisations have to distinguish themselves from their competitors in terms of the quality of their service delivery. In order to attain this new goal organisations realise the important role that customers play in their success. Organisations also recognize that modern day customers have different wants and higher expectations regarding service delivery compared to only a decade ago. To live up to these new challenges a novel form of conducting business was introduced to the global labour market: Telephone call centres provide quality and efficient service in the most cost-effective way possible by, inter alia, utilising customer service representatives (CSRs) to attend to clients’ each and every need – this job demand is termed emotional labour. Due to the way in which the CSRs’ work is structured and the wide-ranging demands placed on them, these individuals experience countless and varied stressors on the job. The result, in a nutshell, is that CSRs become emotionally exhausted and eventually leave the call centre. The purpose of the present research study is, therefore, to identify to what extent emotional labour influences CSRs’ feelings of emotional exhaustion, and whether the latter results in detrimental outcomes that undermine organisations’ success and competitive advantage in the marketplace. A large organisation’s call centre operators participated in the study (n = 84). Seven focus groups were conducted for the purpose of qualitative data collection: Six groups consisted of CSRs (N = 30) and one group consisted of team leaders (N = 4). Qualitative content analysis was used to analyse the focus group interviews. The participants (n = 84) also completed questionnaires measuring emotional labour, emotional exhaustion, supervisor support, organisational commitment, and intentions to leave. Analysis of the interview data supported the existence of the five theoretical constructs and additional sources of job stress, over and above emotional labour, were identified. Pearson product-moment correlation analysis was used to analyse the questionnaire data, followed by multiple regression analysis with organisational commitment and intentions to leave as dependent variables, and the remaining constructs as the predictors. After determining the fit of the measurement model, consisting of the five constructs, a structural model was tested. Both the measurement and structural models produced acceptable goodness-of-fit statistics. The results of the structural model did not indicate a significant correlation between the total construct emotional labour and emotional exhaustion. Significant correlations were found between emotional labour and supervisor support, emotional exhaustion and organisational commitment and intentions to leave respectively, and organisational commitment and intentions to leave. Multiple regression analysis indicated emotional exhaustion is a significant predictor of both lowered organisational commitment and increased intentions to leave. Structural equation modelling indicated emotional exhaustion is causally related to intentions to leave through organisational commitment. The findings are congruent with previous research on the detrimental effect of emotional exhaustion on organisational outcomes and illuminate the complex relationship between emotional labour and emotional exhaustion. Interventions minimising the impact of both emotional labour and emotional exhaustion, within a call centre environment, are explored.

Queueing theory has often been applied to study communication and service queueing systems such as call centers, hospital emergency departments and ride-sharing platforms. Unfortunately, it is complicated to analyze queueing systems. That is largely because the arrival and service processes that mainly determine a queueing system are uncertain and must be represented as stochastic processes that are difficult to analyze. In response, service providers might be able to partially capture the main characteristics of systems given partial data information and limited domain knowledge. An effective engineering response is to develop tractable approximations to approximate queueing characteristics of interest that depend on critical partial information. In this thesis, we contribute to developing high-quality approximations by studying tight bounds for the transient and the steady-state mean waiting time given partial information. We focus on single-server queues and multi-server queues with the unlimited waiting room, the first-come-first-served service discipline, and independent sequences of independent and identically distributed sequences of interarrival times and service times. We assume some partial information is known, e.g., the first two moments of inter-arrival and service time distributions. For the single-server GI/GI/1 model, we first study the tight upper bounds for the mean and higher moments of the steady-state waiting time given the first two moments of the inter-arrival time and service-time distributions. We apply the theory of Tchebycheff systems to obtain sufficient conditions for classical two-point distributions to yield the extreme values. For the tight upper bound of the transient mean waiting time, we formulate the problem as a non-convex non-linear program, derive the gradient of the transient mean waiting time over distributions with finite support, and apply classical non-linear programming theory to characterize stationary points. We then develop and apply a stochastic variant of the conditional gradient algorithm to find a stationary point for any given service-time distribution. We also establish necessary conditions and sufficient conditions for stationary points to be three-point distributions or special two-point distributions. Our studies indicate that the tight upper bound for the steady-state mean waiting time is attained asymptotically by two-point distributions as the upper mass point of the service-time distribution increases and the probability decreases, while one mass of the inter-arrival time distribution is fixed at 0. We then develop effective numerical and simulation algorithms to compute the tight upper bound. The algorithms are aided by reductions of the special queues with extremal inter-arrival time and extremal service-time distributions to D/GI/1 and GI/D/1 models. Combining these reductions yields an overall representation in terms of a D/RS(D)/1 discrete-time model involving a geometric random sum of deterministic random variables, where the two deterministic random variables have different values, so that the extremal waiting times need not have a lattice distribution. We finally evaluate the tight upper bound to show that it offers a significant improvement over established bounds. In order to understand queueing performance given only partial information, we propose determining intervals of likely performance measures given that limited information. We illustrate this approach for the steady-state waiting time distribution in the GI/GI/K queue given the first two moments of the inter-arrival time and service time distributions plus additional information about these underlying distributions, including support bounds, higher moments, and Laplace transform values. As a theoretical basis, we apply the theory of Tchebycheff systems to determine extremal models (yielding tight upper and lower bounds) on the asymptotic decay rate of the steady-state waiting-time tail probability, as in the Kingman-Lundberg bound and large deviations asymptotics. We then can use these extremal models to indicate likely intervals of other performance measures. We illustrate by constructing such intervals of likely mean waiting times. Without extra information, the extremal models involve two-point distributions, which yield a wide range for the mean. Adding constraints on the third moment and a transform value produces three-point extremal distributions, which significantly reduce the range, yielding practical levels of accuracy.

[français] L’objectif de cette recherche est d’analyser l’organisation interne d’une firme de sondage sous l’angle des sphères du milieu de travail telles qu’identifiées par Bélanger, Giles et Murray (2004), soient : la gestion de la production, l’organisation du travail et la relation à l’emploi. Plus spécifiquement, nous chercherons à savoir comment se comporte la firme enquêtée face à la gestion de la flexibilité organisationnelle et quel est l’impact de celle-ci sur les trois sphères du travail. L’analyse utilise la méthodologie de l’étude de cas et fait appel à divers types de matériaux : des observations ponctuelles, des entrevues informelles et les bases de données administratives ainsi que les rapports d’évaluation des entrevues téléphoniques effectuées par les intervieweurs. De même, l’analyse des résultats utilise à la fois des méthodes plus classiques telles que les corrélations ainsi que des représentations graphiques et des analyses qualitatives. L’analyse permet de repérer une logique de fonctionnement à l’œuvre dans les différentes sphères de l’emploi : l’importante standardisation des processus de travail (dans le champ de la gestion de la production), la réduction des marges de manœuvre (dans le champ de l’organisation du travail) et la non reconnaissance de l’expertise des intervieweurs (dans le champ de la relation à l’emploi). Les contradictions repérées dans l’analyse, entre les sphères de l’emploi et les objectifs de flexibilité, montrent que les structures mises en place bloquent, dans une certaine mesure, la capacité d’initiative et d’adaptation que la flexibilité exige. La recherche a montré que ce qu’on demande aux intervieweurs est à la fois le reflet des exigences de la flexibilité, tel que constaté dans ce mémoire, mais aussi, des exigences sociales face à la méthodologie de sondage. Tout porte à déduire que celles-ci peuvent engendrer un plafonnement de la performance des employés. Mots-clés : centres d’appels, intervieweurs, firmes de sondage, flexibilité organisationnelle, gestion de la production, organisation du travail, relation à l’emploi, travail émotionnel. / [english] The objective of this study is to analyze the internal organization of a polling firm from the perspective of workplace spheres, as identified by Bélanger, Giles and Murray (2004): production management, work organization and employment relations. More specifically, we sought to discover how the studied firm behaved in terms of managing organizational flexibility and its impact on the three aforementioned spheres. The analysis uses case-study methodology and calls upon various types of material: point source observations, informal interviews, as well as administrative databases and assessment reports of telephone interviews carried out by interviewers. In addition, the analysis employs both classical methods such as correlations, as well as graphical representations and qualitative analyses. The analysis traces an operational logic from the point of view of the different spheres: the significant standardization of the work process (in the sphere of production management), the reduction of flexibility (in the sphere of work organization), and the non-recognition of interviewer expertise (in the sphere of employment relations). The contradictions revealed by the analysis between the spheres of work and the goals of flexibility demonstrate that the structures currently in place block, to a certain extent, the capacities for initiative and adaptation required by flexibility. The research demonstrates that what is asked of interviewers is both a reflection of the requirements of flexibility, as seen in this thesis, but also of social requirements related to survey methodology. All of which points to the conclusion that these requirements can lead to a leveling off of employee performance. Key words: call centers, interviewers, polling firms, organizational flexibility, production management, work organization, work relations, emotional labor. / CRSH