Uno de los principales problemas que preocupa tanto a los teóricos de la ciencia de la administración de empresas, como a los altos ejecutivos de las empresas, es qué estrategia debe aplicar una entidad económica para obtener una ventaja competitiva y, eventualmente, aumentar tanto su cuota de mercado en el mercado en el que opera como para conseguir una mayor rentabilidad. La crisis económica que comenzó en 2008, ha llevado a la recesión a muchos países y muchas empresas se enfrentan a condiciones difíciles en sus operaciones comerciales, lo que en algunos casos es una amenaza directa para su supervivencia. Este hecho ha llevado a un resurgimiento del interés por la recuperación de las empresas y las estrategias necesarias para ello, mientras dichas empresas tratan de mejorar sus resultados durante la recesión (Schoenberg, Collier and Bowman, 2013). Slatter (1984) señala la recesión como la quinta de las 18 operaciones de activación del declive. Los estudios suelen identificar “respuestas de austeridad” y/o “de inversión” para garantizar la supervivencia y la mejora de los resultados (por ejemplo, Robbins y Pearce II, 1992; Denis y Kruse, 2000), aunque tales esfuerzos pueden fracasar (por ejemplo, Slatter, 1984; Pajunen, 2008). Las revisiones de la literatura sobre recuperación, muestran que la austeridad es la clave para una recuperación exitosa, ya sea a través de un enfoque autónomo, o como preludio de una estrategia de recuperación (Pearce II y Robbins, 1993; Barker III y Duhaime, 1997). La estrategia de recuperación pertenece al grupo de estrategias empresariales de rescate/reversión y es utilizada principalmente por las empresas que se enfrentan a problemas económicos o de otra índole y que intentan superar la situación poco propicia a la que se enfrentan. Además, esta estrategia es utilizada alternativamente por las empresas que desean prevenir problemas futuros. Estos casos se caracterizan por la falta de recursos, la escasa confianza de los empleados, la falta de tiempo o el fracaso de la gestión. La causa de estos problemas son los cambios repentinos en los requisitos de los factores externos del mercado, ya sean competidores, proveedores o clientes (Johnson y Scholes, 2002). El objetivo general de la estrategia de recuperación es revertir la situación de estancamiento y recuperar la normalidad en términos de niveles aceptables de rentabilidad. Para aplicar esta estrategia, es necesario diagnosticar las causas de los problemas a los que se enfrenta la empresa y también es necesario comprender el marco macroeconómico general, así como el microentorno de la industria específica. Las razones que llevan a un deterioro significativo de los resultados económicos de la empresa pueden ser tanto internas (factores internos) como externas (factores externos). Además, algunos autores como Barker III y Duhaime (1997) y Pearce y Robbins (1993) también plantean la cuestión de la categorización del descenso de los negocios si éste se produce por causas propias (internas) o por una bajada general del sector. Schendel, Patton y Riggs (1976) se centraron en el análisis de las verdaderas razones del declive de una empresa, clasificándolas en función de si se derivan de la falta de aplicación de los cambios, de estrategias inadecuadas, de procesos y operaciones imprecisas y costosas, o del fracaso total de la estrategia. Investigaciones posteriores de Schendel y Patton (1975), demuestran que existen marcadas diferencias en determinadas variables que son descritas por las empresas que han aplicado con éxito la estrategia de recuperación. Tras analizar las causas que llevan a una empresa a sufrir pérdidas, hay que valorar si merece la pena mantenerla en funcionamiento y no declararla en bancarrota como mencionan Routledge y Gadenne (2004), quienes identifican que la primera decisión importante que se debe tomar es si la empresa debe ser reorganizada o liquidada y, finalmente, si la decisión no es liquidar, la alta dirección debe aplicar una estrategia de recuperación. La aplicación de la estrategia de recuperación se logra mediante una planificación adecuada y procedimientos concretos (procesos); a título indicativo, podemos mencionar algunos de ellos, como la gestión del cambio, la desinversión de activos específicos, la reducción de costes (operativos y otros) y las adquisiciones estratégicas. Sin embargo, en la literatura existente no hay ningún estudio sobre las estrategias de recuperación empresariales, ni durante la recesión económica, ni en condiciones sin precedentes como las de la economía griega, que analicen la conveniencia de aplicar las tácticas utilizadas y el impacto de los factores internos y externos en el plan estratégico, la facturación, los resultados, el ROI y el ROA de la empresa. Además, tratamos de entender el impacto en el éxito de la recuperación, según quién elabora la estrategia de la empresa. Esta investigación se lleva a cabo en unas condiciones sin precedentes para la economía griega, con una caída del PIB de 237.000 millones en 2009 a 179.000 millones en 2014, y un aumento del desempleo del 9% en 2009 al 27% en 2015 (Autoridad Estadística Helénica). En el primer capítulo de este trabajo, intentamos atribuir la importancia conceptual de la estrategia y la gestión estratégica, así como su desarrollo y utilidad. Además, analizamos el entorno externo que afecta a la estrategia empresarial, así como la jerarquía de las estrategias. En el segundo capítulo, hacemos referencia a la estrategia operativa a la que pertenece la estrategia de recuperación. En el tercer capítulo, hablamos de la definición de crisis en general, pero también de la crisis de las empresas y de su ciclo de vida. Hacemos referencia a las crisis económicas más importantes que ha vivido el planeta, así como una amplia referencia a la crisis económica de Grecia, país sobre el que trata esta investigación. Además, se incluye una descripción y un análisis de la situación de las empresas griegas durante el período pandemia-covid 19. Así mismo, se incluyen referencias bibliográficas y un análisis detallado de la gestión del cambio en el cuarto capítulo, tanto por su importancia como por su interpretación. Nos referimos a la interpretación cuantitativa del cambio y a los criterios que determinan que una empresa se encuentra en una situación crítica, pero también a los criterios que indican que una empresa ha vuelto a la normalidad. En el mismo capítulo, presentamos un informe detallado sobre las causas por las que una organización puede encontrarse en una situación crítica, así como la división de dichas causas en externas e internas. En el capítulo 4, hacemos referencia a las estrategias de recuperación, pero también a los modelos de recuperación que se mencionan en la literatura, así como a los factores de éxito de una estrategia de recuperación. También se hace referencia a la categorización de las empresas que aplican una estrategia de recuperación en función de los resultados de la misma. En el quinto capítulo, se hace referencia a las metodologías de investigación que llevamos a cabo para las operaciones griegas. Inicialmente, con la ayuda de la estadística descriptiva, analizamos las características demográficas de quienes participaron en la encuesta y de las empresas que representaban. Registramos los porcentajes de influencia de sus factores empresariales, como su plan estratégico, sus resultados, su facturación, su ROI y su ROA. Recogemos en porcentaje los factores externos e internos que influyeron en ellos, los resultados que se obtuvieron y las tácticas que se aplicaron. En el mismo capítulo, con la ayuda de modelos estadísticos, llegamos a conclusiones útiles para la correlación de numerosos factores relativos al índice de facilidad/dificultad de aplicación de las tácticas que se aplicaron, así como para la correlación de los factores que aportaron resultados exitosos, pero también la importancia que tienen para obtener resultados exitosos, para quien formula y aplica el plan estratégico. Además, se describen conclusiones útiles para el orden correcto de las tácticas de recuperación aplicadas en base a la experiencia y los conocimientos de los directivos de las empresas griegas. Para el análisis de todos ellos, se utilizaron las pruebas Chi cuadrado de Pearson, los modelos de coeficiente de correlación de Spearman, la prueba de Kruskal Wallis (análisis de la varianza) y la regresión logística binaria. Adicionalmente, aplicamos análisis factorial, análisis de conglomerados implementado y analizado con prueba de correlación de coeficiente de Spearmen y análisis ANOVA.

Gas plants consist of several pieces of both critical static and rotating equipment, which operate continuously under severe operating conditions. These pieces of equipment are permanently subjected to be inspected and maintained during total shutdown of plant facilities to execute Turnaround Maintenance (TAM) event. The TAM is the largest maintenance activities used in most oil and gas companies in terms of both cost and time. Oil and gas companies have suffered losses in the production and enormity in the TAM cost due to duration and interval of TAM which have randomly estimated without taking the size and age of plants into account. Sirte Oil Company (SOC) was a good example and used as a reference point for other gas plants to achieve the aim of this thesis associated with optimising TAM scheduling for gas plants (decreasing duration and increasing interval of TAM) by implementing the TAM model. The contribution of this research is in developing the TAM model, consisting of four stages, which is broken down into four main stages: First stage; removing Non-critical pieces of Equipment (NEs) from the Scope of Work (SoW) of TAM to proactive maintenance strategies. Second stage; selecting Critical Static pieces of Equipment (CSEs) that constitute the highest risk based on Risk-Based Inspection (RBI). Third stage; selecting Critical Rotating pieces of Equipment (CREs) that constitute the highest risk based on Risk-Based Failure (RBF). Fourth stage; defining the optimum duration and interval of TAM based on Failure Distributions (FDs). Consequently, the TAM model developed in this study provides a novelty in the TAM event and decision making process. This is basically about optimisation of TAM scheduling in the medium and long-term, characterized by decreasing duration and increasing interval of TAM based on both CSEs and CREs to achieve the TAM model results. The result is the reduction in TAM cost and production losses, and the improvement in reliability and availability requirements of gas plants according to the residual life of critical equipment and operating conditions. To ensure reliability and consistency of the TAM model, it was validated with three Libya-plants SOC and data from three published case studies. The results from the validation of the TAM model are consistent with the real duration and interval of TAM in most plants SOC. The research concludes that the developed TAM model is a reliable and applicable tool to assist decision-makers in the estimation of TAM scheduling for any a processing plant.

No description available.

Efficient ground handling at airports greatly adds to the performance of the entire air transportation network. In this network, airports are connected via aircraft that rely on passenger and crew connections, successful local airport operations, and efficient ground handling resource management. In addition, airport stakeholders’ decision-making processes must take into account various time scales (look-ahead times), process estimates, and both limited and multiple-dependent solution spaces. Most airlines have created integrated hub and operations control centers to monitor and adapt tactical operations. Despite this, decisions in such control centers should be made quickly in case of disruption. The decisions should also include the interests of various airline departments and local stakeholders. Taking into account the Airport Collaborative Decision Making (A-CDM) concept, the joint venture between Airports Council International Europe (ACI EUROPE) - European Organization for the Safety of Air Navigation (EUROCONTROL) - International Air Transport Association (IATA) - Civil Air Navigation Services Organization (CANSO), this study creates different tools to manage turnaround in normal and disrupted contexts, hence facilitating decision-making in an Airport Operations Control Center (AOCC) and a Hub Control Center (HCC). This research focuses on the airline role in the collaborative decision-making process. Regarding A-CDM milestones, turnaround time estimation is computed by four modeling methodologies, namely Critical Path Method (CPM), Project Evaluation and Review Technique (PERT), Fuzzy Critical Path Method (FCPM), and Analytical Convolution in deterministic and nondeterministic domains. In addition, the study develops mathematical models to return the airline schedule to its original plan in the event of delays. Chance-constrained and Robust optimization are also created for optimal decision-making when airlines confront uncertainty during real-world operations. The study also develops a novel Hybrid Shuffled Frog-Leaping Algorithm (SFLA)-Grasshopper Optimization Algorithm (GOA) to expedite the process of finding recovery solutions, allowing AOCC and HCC for real-time applications to send this information to the relevant departments. In comparison to common linear solvers, the solution process is sped up by 18 percent and the quality of the solutions is enhanced by 24 percent on average. Initial results are generated in less than 2 minutes, and global optimal results are achieved in near 15 minutes allowing the system to be applied in real-time applications.:Abstract 1 Introduction 1.1 Problem Description 1.1.1 Decision Scope 1.1.2 Airport Collaborative Decision Making (A-CDM) 1.1.3 Total Airport Management 1.1.4 Ground Handlers 1.1.5 Turnaround Management 1.2 Aims and Objectives 1.3 Thesis Contribution 1.4 Structure 2 Literature Review 2.1 Turnaround 2.2 Ground Handling 2.3 Flights and Networks 2.4 Apron and Gate Assignment 2.5 Scopes Combination 2.5.1 Gate Assignment and Turnaround 2.5.2 Gate Assignment and Flights 2.5.3 Gate Assignment and Ground Handling 2.5.4 Turnaround and Flights 2.5.5 Turnaround and Ground Handling 2.5.6 Flights and Ground Handling 2.6 Turnaround Operations 2.7 Conclusion 3 Turnaround Definition 3.1 Turnaround in A-CDM System 3.2 Turnaround and Ground Handling 3.3 Turnaround Operations 3.3.1 In-Block (INB) and Acceptance (ACC) 3.3.2 Deboarding (DEB) and Boarding (BOA) 3.3.3 Fueling (FUE) 3.3.4 Catering (CAT) 3.3.5 Cleaning (CLE) 3.3.6 Unloading (UNL) and Loading (LOA) 3.3.7 Water service (WAT) and Toilette (TOI) 3.3.8 Finalization (FIN) 4 Total Turnaround Time (TTT) Calculation 4.1 Critical Path Method (CPM) 4.2 Project Evaluation and Review Technique (PERT) 4.3 Fuzzy Critical Path Method (FCPM) 4.3.1 Fuzzy Numbers and Fuzzy Sets 4.3.2 Fuzzy Membership Functions of Turnaround Tasks 4.3.3 Probability-possibility Transformation of Turnaround Tasks 4.3.4 Fuzzy Critical Path Method (FCPM) in Total Turnaround Time (TTT) Calculation 4.3.5 Discussion 4.4 Analytical Convolution 4.4.1 Convolution Method 4.4.2 Monte Carlo (MC) Simulation Evaluation 4.4.3 Application of Convolution in Turnaround Control 5 Disruption Management 5.1 Airline Disruption Management 5.1.1 Airport Operations Control Center (AOCC) 5.1.2 Delay in the Airline Networks 5.1.3 Recovery Options 5.2 Deterministic Model 5.2.1 Mathematical Model 5.2.2 Solution Approaches 5.2.3 Problem Setting 5.3 Non Deterministic Model 5.3.1 Stochastic Arrivals 5.3.2 Stochastic Duration 6 Conclusion 6.1 Discussion around Research Questions 6.1.1 Integration of All Actors 6.1.2 Turnaround Time Prediction 6.1.3 Quick and Robust Reaction 6.2 Future Research 6.2.1 Scope Development 6.2.2 Algorithm Development 6.2.3 Parameter Development List of Acronyms List of Figures List of Tables Bibliography Acknowledgement

As the number of English learners (ELs) grows in the United States, so does the achievement gap between ELs and non-ELs. Research highlights the effective leadership of school principals who lead with instructional, social justice, and collaborative leadership styles. School leaders can close achievement gaps but the research on the field of school leadership for ELs is limited. The purpose of this qualitative study was to identify the specific leadership practices elementary school principals implement to support the academic and non-academic needs of ELs. The study was conducted in one school division in the Mideastern United States using semi-structured interviews. This study generated nine findings and nine implications. Among the findings, school principals communicated high expectations for ELs prioritizing ELs' access to core content, established structures to support ELs' English language development, used data to guide instructional outcomes, promoted collective teacher efficacy within the context of a collaborative learning team, and provided ongoing professional learning opportunities to staff. In addition, school principals cultivated an environment of inclusion and access and set up structures that increased family engagement, encouraged the collaboration of multiple stakeholders, and supported the socio-emotional needs of ELs. One major implication is for state and national boards of education to consider establishing professional standards that outline specific knowledge and practice expectations for effective leadership and successful outcomes of ELs and for school divisions and principal preparation programs to provide coaching, technical assistance, and support structures to address the identified findings. Other implications included the need for school division leaders to provide professional development for school leaders and instructional staff on effective instructional methods, strategies, and supports for ELs, as well as technical assistance for schools to disaggregate and analyze EL performance in their data discussions in collaborative learning teams, a professional space where the academic needs of ELs can be addressed. Additionally, other implications included for school division leaders to develop systematic processes for equity and access, supporting schools' structures to target socio-emotional needs of ELs, and providing and expanding opportunities for family and community engagement. / Doctor of Education / The achievement gap between English learners (ELs) and non-ELs continues to grow. Effective school leaders can close the achievement gap for ELs but need systematic and explicit guidelines and programs to support the growing numbers of ELs in their schools. The purpose of this qualitative study was to identify the leadership practices elementary school principals implement to address the academic and non-academic needs of ELs. Elementary school principals from a school division in the Mideastern United States were interviewed. This study generated nine findings and nine implications. One suggestion for further research is to replicate this study at the secondary level or with school divisions that have high academic performance of ELs in low incidence schools in order to develop comprehensive K–12 professional standards that outline specific knowledge and practice expectations for effective leadership and successful outcomes of ELs.

A school community is often more than meets the eye. With more research highlighting the benefits of school-community partnerships, the notion of what constitutes community in an elementary school setting leaves much room to be further examined. In this study, community is considered through two lenses: a geographically-defined community and a sense of community defined by mutual sensibilities, goals, and practices (Weathers, 2011; Wenger, 1998). The purpose of this study was to understand faculty and staff perceptions of community in a challenged urban elementary school. A qualitative research methodology with a phenomenological approach was used in this case study. Participants included the faculty, staff, and the leadership team currently employed at an elementary school. Data collection methods included semi-structured interviews, participant conversations, observations, artifacts, and document analysis. These methods were used to capture the phenomenon and experiences of people working in and with the school. Three themes emerged from the data, describing who and what contribute to community in a challenged urban elementary school: (a) members of the community, (b) the prioritization of students at the school, and (c) the intractable problems that exist within the school, both on micro and macro levels. Based on these findings, the main conclusion was that teachers played the biggest role in prioritizing students, as they were the community members most immersed with students on a daily basis. Additional conclusions were: (a) the level of student need is high, (b) intractable problems challenge the development of community, and (c) principal and teacher turnover challenge the development of community. / Doctor of Philosophy / A school community is often more than meets the eye. With more research highlighting the benefits of school-community partnerships, the notion of what constitutes community in an elementary school setting leaves much room to be further examined. In this study, community is considered through two lenses: a geographically-defined community and a sense of community defined by mutual interests, goals, and practices. The purpose of this study was to understand faculty and staff perceptions of community in a challenged urban elementary school. I conducted my research at an elementary school in the Southeastern part of the United States. I focused on the faculty, staff, and the leadership team at the elementary school. I interviewed faculty and staff, had conversations, observed within the school, took photos, and examined documents that helped me better understand the school and its community. In my findings, I described who and what contribute to community: (a) members of the community, (b) the prioritization of students at the school, and (c) the intractable problems that exist within the school. The main conclusion in this study was that teachers played the biggest role in prioritizing students, as they were the community members most immersed with students on a daily basis. Additional conclusions were: (a) the level of student need is high, (b) intractable problems challenge the development of community, and (c) principal and teacher turnover challenge the development of community.

The purpose of the study was to describe the process of simultaneous implementation of the Indistar model of school improvement and the University of Virginia School Turnaround model of school improvement and how those models influenced school improvement practices in a rural Southwest Virginia school system. Best practices from each of the school improvement models were identified and adopted, which led to the establishment of a hybrid model of school improvement. The study documents how and why the practices were adopted and used in the hybrid model. The paper includes a literature review which examines the evolution of school improvement in the U.S. The description of the historical development of school reform sets the context for in-depth reviews of five current research studies. The studies selected for review, as well as the research study, focus on the role of the central office in school improvement. A synthesis of the studies' findings provided evidence that further research was needed. Data sources for the study include an individual interview of the superintendent, focus group interviews of central office administration and school leadership teams, archival records, and documents. The focus group interviews were conducted to describe the process of implementation of the two school improvement models and to identify school improvement practices that were adopted by the division. This study identifies the practices that were adopted and implemented throughout the rural Southwest Virginia school system. Best practices that are used in the hybrid model of school improvement are Professional Learning Communities, acceleration teams, 90-day school improvement plans, and a tiered remediation program. Barriers to implementation of school improvement were time, the initial lack of support in the Indistar model, involvement, and the understanding of data and data analysis. The themes of professional development, external and internal supports, and sustainability of school improvement are discussed in Chapter 5. Recommendations for practice and future research are presented. / Ed. D.

The purpose of this study was to investigate turnaround reform by identifying student factors from the perspective of successful turnaround leaders in Virginia that hinder or aid the process and the supports in place to address learning issues. It was determined, through a literature review, that research focused on the school culture, leadership, teacher and parent factors concerning turnaround reform efforts, but there was little mention of students beyond the scores they produce on end-of-the-year standardized tests. The central research question investigated the student-related factors that impact a school's ability to increase academic achievement within the turnaround process. Interviews were conducted with four successful turnaround principals in Virginia. The results of the study indicated the student factors thought to impact learning were reading issues, teacher competency issues, students' personal needs, attendance issues, and discipline issues. While the first inclination of school leaders in a failing school may be to find the 'quick fix' to turn scores around, the principals in this study focused on three fundamental goals: get the students to read more, keep students in the classroom, and meet students' needs. Research in the area of turnaround strategies and implementation is useful for school boards and principals as they endeavor to raise the achievement of their students. This study of successful turnaround organizations focusing on how student-related factors impact academic performance would be beneficial in determining whether the organizational structure supports or hinders Priority School reform. This examination of how student-related factors contribute to an organization's capability to turn around low performance informs administrators and policy makers on strategies to overcome the learning barriers that may exist. / Ed. D.

The intent of this non-experimental correlational and comparative study was to determine the extent to which self-efficacy predicts student achievement as well as the differences between the self-efficacy beliefs of principals in turnaround and fully accredited schools at the elementary, middle, and high school levels in one urban Virginia school division. Principal leaders should be selected based on expertise related to their assigned school needs and challenges (Murphy, 2010a). Turnaround schools in the process of improvement present a distinct challenge and require individualized applications of effective leadership practices (Leithwood, Harris and Strauss, 2010). Principal self-efficacy is defined as, "...a judgment of his or her own capabilities to structure a particular course of action in order to produce desired outcomes in the school he or she leads" (Tschannen-Moran and Gareis, 2004, p. 573). Overall principal self-efficacy as well as efficacy for management, instructional leadership, and moral leadership were measured using the Principal Sense of Efficacy Scale (PSES) (Tschannen-Moran and Gareis, 2004). The Virginia Standards of Learning (SOL) assessment results for reading and mathematics, specifically the overall school pass rates by subject, were used as indicators of student achievement. The researcher sought to examine the usefulness of measuring self-efficacy as a potential method for identifying and assigning principals to specific school contexts based on any relationships and differences revealed by the data. A hierarchical multiple regression analysis was used to predict student achievement in reading and mathematics from overall principal self-efficacy and the three principal efficacy subscales while controlling for poverty. An independent samples t-test was conducted to compare the self-efficacy of principals at turnaround and fully accredited schools. Analysis of the predictive relationship between principal self-efficacy and student achievement in reading and mathematics failed to reveal significant findings. Comparative analysis of the mean self-efficacy for turnaround and fully accredited school principals further failed to reveal statistically significant differences. Calculated effect size of the differences between the groups indicated a medium effect. Implications for practice and recommendations for future research were developed from the findings. / Ed. D.

This case study addressed the factors that enhanced or constrained the success of one Promise Academy at an elementary school in the northeastern United States. A large number of schools in an urban district have continuously failed to make adequate yearly progress (AYP). The study school implemented the Promise Academy model in September 2010, to dramatically improve and transform the learning environment in this underperforming school. Promise Academies, the district turnaround model, was implemented in 11 schools, all of which have failed to produce increases in student outcomes. The theoretical framework supporting this study was Michael Fullan's theory of educational change. Using a qualitative goals based program evaluation, the research questions explored the stakeholders' perspectives on the implementation of one Promise Academy. For this qualitative study, interview data were collected and analyzed by using open coding and analytical coding. The common themes identified helped to examine and understand the factors that participants' reported as having constrained and enhanced the implementation of the Promise Academy model and student achievement. The key stakeholders in this case study included 10 teachers, 3 parents and 2 administrators. The results included in the evaluation report reflected that the implementation of the Promise Academy had a positive impact on student learning during the first 2 years of the model, however, this was followed by a decline in student achievement during the third year and beyond. The recommendations included a continued plan of action throughout the intended duration of the reform model. Positive school turnaround can lead to higher graduation rates which can positively affect the quality of the community, which will ultimately lead to positive social change.