Segev Wasserkrug - Academia.edu (original) (raw)

Papers by Segev Wasserkrug

Research paper thumbnail of Uncertainty in Events

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Research paper thumbnail of Event Prediction

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Research paper thumbnail of Event Processing over Uncertain Data

Events are the main input of event-based systems. Some events are generated externally and flow a... more Events are the main input of event-based systems. Some events are generated externally and flow across distributed systems, while other events and their content need to be inferred by the event-based system itself. Such inference has a clear trade-off between inferring events with certainty, using full and complete information, and the need to provide a quick notification of newly revealed events. Timely event inference is therefore hampered by the gap between the actual occurrences of events, to which the system must respond, and the ability of event-based systems to accurately infer these events. This gap results in uncertainty and may be attributed to unreliable data sources (e.g., an inaccurate sensor reading), unreliable networks (e.g., packet drop at routers), the use of fuzzy terminology in reports (e.g., normal temperature) or the inability to determine with certainty whether a phenomenon has occurred (e.g., declaring an epidemic). In this chapter we present the state-of-the-art in event processing over uncertain data. We provide a classification of uncertainty in event-based systems, define a model for event processing over uncertain data, and propose algorithmic solutions for handling uncertainty.We also define, for demonstration purposes, a simple pattern language that supports uncertainty and detail open issues and challenges in this research area.

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Research paper thumbnail of Utilizing model characteristics to obtain efficient parallelization in the context of agent based epidemiological models

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Research paper thumbnail of Handling Uncertain Rules in Composite Event Systems

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Research paper thumbnail of A Taxonomy and Representation of Sources of Uncertainty in Active Systems

In recent years, there has been an increased need for the use of active systems – systems that in... more In recent years, there has been an increased need for the use of active systems – systems that include substantial processing which should be triggered by events. In many cases, however, there is an information gap between the actual occurrences of events to which such a system must respond, and the data generated by monitoring tools regarding these events. For example, some events, by their very nature, may not be signaled by any monitoring tools, or the inaccuracy of monitoring tools may incorrectly reflect the information associated with events. The result is that in many cases, there is uncertainty in the active system associated with event occurrence. In this paper, we provide a taxonomy of the sources of this uncertainty. Furthermore, we provide a formal way to represent this uncertainty, which is the first step towards addressing the aforementioned information gap.

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Research paper thumbnail of Efficient uncertainty management in complex event systems: saving the witch from Henzel & Gretel

ABSTRACT

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Research paper thumbnail of Inference and Prediction of Uncertain Events in Active Systems: A Language and Execution Model

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Research paper thumbnail of Business objective based resource management

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Research paper thumbnail of Toward Simulation-based Real-time Decision-support Systems for Emergency Departments

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Research paper thumbnail of Improving efficiency in software maintenance

ABSTRACT Efficiency is critical to the profitability of software maintenance and support organiza... more ABSTRACT Efficiency is critical to the profitability of software maintenance and support organizations. Managing such organizations effectively requires suitable measures of efficiency that are sensitive enough to detect significant changes, and accurate and timely in detecting them. Mean time to close problem reports is the most commonly used efficiency measure, but its suitability has not been evaluated carefully. We performed such an evaluation by mining and analyzing many years of support data on multiple IBM products. Our preliminary results suggest that the mean is less sensitive and accurate than another measure, percentiles, in cases that are particularly important in the maintenance and support domain. Using percentiles, we also identified statistical techniques to detect efficiency trends and evaluated their accuracy. Although preliminary, these results may have significant ramifications for effectively measuring and improving software maintenance and support processes.

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Research paper thumbnail of A top-down approach to aligning business service centres with business processes

International Journal of Services Operations and Informatics, 2008

... Segev is currently the technical lead for the SWOPS workforce management tool, and is an IBM ... more ... Segev is currently the technical lead for the SWOPS workforce management tool, and is an IBM research sub-strategist in the area of Services Analytics and Optimisation. 1 Introduction The beginning of the 21st century marks the era in which the structure of business begins to ...

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Research paper thumbnail of Analytics-driven asset management

Ibm Journal of Research and Development, 2011

Asset-intensive businesses across industries rely on physical assets to deliver services to their... more Asset-intensive businesses across industries rely on physical assets to deliver services to their customers, and effective asset management is critical to the businesses. Today, businesses may make use of enterprise asset-management (EAM) solutions for many asset-related processes, ranging from the core asset-management functions to maintenance, inventory, contracts, warranties, procurement, and customer-service management. While EAM solutions have transformed the operational aspects of asset management through data capture and process automation, the decision-making process with respect to assets still heavily relies on institutional knowledge and anecdotal insights. Analytics-driven asset management is an approach that makes use of advanced analytics and optimization technologies to transform the vast amounts of data from asset management, metering, and sensor systems into actionable insight, foresight, and prescriptions that can guide decisions involving strategic and tactical assets, as well as customer and business models.

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Research paper thumbnail of InEDvance: Advanced IT in Support of Emergency Department Management

Emergency Departments (ED) are highly dynamic environments comprising complex multi-dimensional p... more Emergency Departments (ED) are highly dynamic environments comprising complex multi-dimensional patient-care processes. In recent decades, there has been increased pressure to improve ED services, while taking into account various aspects such as clinical quality, operational efficiency, and cost performance. Unfortunately, the information systems in today’s EDs cannot access the data required to provide a holistic view of the ED in a complete and timely fashion. What does exist is a set of disjoint information systems that provide some of the required data, without any additional structured tools to manage the ED processes. We present a concept for the designof an IT system that provides advanced management functionality to the ED. The system is composed of three major layers: data collection, analytics, and the user interface. The data collection layer integrates the IT systems that already exist in the ED and newly introduced systems such as sensor-based patient tracking. The analytics component combines methods and algorithms that turn the data into valuable knowledge. An advanced user interface serves as a tool to help make intelligent decisions based on that knowledge. We also describe several scenarios that demonstrate the use and impact of such a system on ED management. Such a system can be implemented in gradual stages, enabling incremental and ongoing improvements in managing the ED care processes. The multi-disciplinary vision presented here is based on the authors’ extensive experience and their collective records of accomplishment in emergency departments, business optimization, and the development of IT systems.

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Research paper thumbnail of Shift Scheduling for Third Level IT Support: Challenges, Models and Case Study

Outsourcing IT support of an enterprise requires that third level IT support is provided as a ser... more Outsourcing IT support of an enterprise requires that third level IT support is provided as a service by the outsourcer. Although there is a large body of existing work regarding demand forecasting and shift schedule creation for various domains such as call centers, very little work exists for third level IT support. Moreover, there is a significant difference between such

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Research paper thumbnail of Efficient Processing of Uncertain Events in Rule-Based Systems

IEEE Transactions on Knowledge and Data Engineering, 2012

There is a growing need for systems that react automatically to events. While some events are gen... more There is a growing need for systems that react automatically to events. While some events are generated externally and deliver data across distributed systems, others need to be derived by the system itself based on available information. Event derivation is hampered by uncertainty attributed to causes such as unreliable data sources or the inability to determine with certainty whether an event has actually occurred, given available information. Two main challenges exist when designing a solution for event derivation under uncertainty. First, event derivation should scale under heavy loads of incoming events. Second, the associated probabilities must be correctly captured and represented. We present a solution to both problems by introducing a novel generic and formal mechanism and framework for managing event derivation under uncertainty. We also provide empirical evidence demonstrating the scalability and accuracy of our approach.

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Research paper thumbnail of A Methodological Framework for Business-Oriented Modeling of IT Infrastructure

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Research paper thumbnail of Calculating the Business Importance of Entities in a Service-Oriented Enterprise

Component business modeling (CBM) serves as a powerful analytical framework for reasoning about t... more Component business modeling (CBM) serves as a powerful analytical framework for reasoning about the business as a set of business components that collaborate through the provision and consumption of business services. This paper proposes and illustrates a method to calculate the relative importance of the entities that make up a componentized enterprise architecture. The proposed method includes a formal definition

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Research paper thumbnail of Waiting and sojourn times in a multi-server queue with mixed priorities

Queueing Systems - Theory and Applications, 2009

We consider a multi-server queue with K priority classes. In this system, customers of the P high... more We consider a multi-server queue with K priority classes. In this system, customers of the P highest priorities (P<K) can preempt customers with lower priorities, ejecting them from service and sending them back into the queue. Service times are assumed exponential with the same mean for all classes. The Laplace–Stieltjes transforms of waiting times are calculated explicitly and the Laplace–Stieltjes transforms of sojourn times are provided in an implicit form via a system of functional equations. In both cases, moments of any order can be easily calculated. Specifically, we provide formulae for the steady state means and the second moments of waiting times for all priority classes. We also study some approximations of sojourn-time distributions via their moments. In a practical part of our paper, we discuss the use of mixed priorities for different types of Service Level Agreements, including an example based on a real scheduling problem of IT support teams.

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Research paper thumbnail of Creating operational shift schedules for third-level IT support: challenges, models and case study

International Journal of Services Operations and Informatics, 2008

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Research paper thumbnail of Uncertainty in Events

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Research paper thumbnail of Event Prediction

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Research paper thumbnail of Event Processing over Uncertain Data

Events are the main input of event-based systems. Some events are generated externally and flow a... more Events are the main input of event-based systems. Some events are generated externally and flow across distributed systems, while other events and their content need to be inferred by the event-based system itself. Such inference has a clear trade-off between inferring events with certainty, using full and complete information, and the need to provide a quick notification of newly revealed events. Timely event inference is therefore hampered by the gap between the actual occurrences of events, to which the system must respond, and the ability of event-based systems to accurately infer these events. This gap results in uncertainty and may be attributed to unreliable data sources (e.g., an inaccurate sensor reading), unreliable networks (e.g., packet drop at routers), the use of fuzzy terminology in reports (e.g., normal temperature) or the inability to determine with certainty whether a phenomenon has occurred (e.g., declaring an epidemic). In this chapter we present the state-of-the-art in event processing over uncertain data. We provide a classification of uncertainty in event-based systems, define a model for event processing over uncertain data, and propose algorithmic solutions for handling uncertainty.We also define, for demonstration purposes, a simple pattern language that supports uncertainty and detail open issues and challenges in this research area.

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Research paper thumbnail of Utilizing model characteristics to obtain efficient parallelization in the context of agent based epidemiological models

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Research paper thumbnail of Handling Uncertain Rules in Composite Event Systems

Bookmarks Related papers MentionsView impact

Research paper thumbnail of A Taxonomy and Representation of Sources of Uncertainty in Active Systems

In recent years, there has been an increased need for the use of active systems – systems that in... more In recent years, there has been an increased need for the use of active systems – systems that include substantial processing which should be triggered by events. In many cases, however, there is an information gap between the actual occurrences of events to which such a system must respond, and the data generated by monitoring tools regarding these events. For example, some events, by their very nature, may not be signaled by any monitoring tools, or the inaccuracy of monitoring tools may incorrectly reflect the information associated with events. The result is that in many cases, there is uncertainty in the active system associated with event occurrence. In this paper, we provide a taxonomy of the sources of this uncertainty. Furthermore, we provide a formal way to represent this uncertainty, which is the first step towards addressing the aforementioned information gap.

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Research paper thumbnail of Efficient uncertainty management in complex event systems: saving the witch from Henzel & Gretel

ABSTRACT

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Research paper thumbnail of Inference and Prediction of Uncertain Events in Active Systems: A Language and Execution Model

Bookmarks Related papers MentionsView impact

Research paper thumbnail of Business objective based resource management

Bookmarks Related papers MentionsView impact

Research paper thumbnail of Toward Simulation-based Real-time Decision-support Systems for Emergency Departments

Bookmarks Related papers MentionsView impact

Research paper thumbnail of Improving efficiency in software maintenance

ABSTRACT Efficiency is critical to the profitability of software maintenance and support organiza... more ABSTRACT Efficiency is critical to the profitability of software maintenance and support organizations. Managing such organizations effectively requires suitable measures of efficiency that are sensitive enough to detect significant changes, and accurate and timely in detecting them. Mean time to close problem reports is the most commonly used efficiency measure, but its suitability has not been evaluated carefully. We performed such an evaluation by mining and analyzing many years of support data on multiple IBM products. Our preliminary results suggest that the mean is less sensitive and accurate than another measure, percentiles, in cases that are particularly important in the maintenance and support domain. Using percentiles, we also identified statistical techniques to detect efficiency trends and evaluated their accuracy. Although preliminary, these results may have significant ramifications for effectively measuring and improving software maintenance and support processes.

Bookmarks Related papers MentionsView impact

Research paper thumbnail of A top-down approach to aligning business service centres with business processes

International Journal of Services Operations and Informatics, 2008

... Segev is currently the technical lead for the SWOPS workforce management tool, and is an IBM ... more ... Segev is currently the technical lead for the SWOPS workforce management tool, and is an IBM research sub-strategist in the area of Services Analytics and Optimisation. 1 Introduction The beginning of the 21st century marks the era in which the structure of business begins to ...

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Research paper thumbnail of Analytics-driven asset management

Ibm Journal of Research and Development, 2011

Asset-intensive businesses across industries rely on physical assets to deliver services to their... more Asset-intensive businesses across industries rely on physical assets to deliver services to their customers, and effective asset management is critical to the businesses. Today, businesses may make use of enterprise asset-management (EAM) solutions for many asset-related processes, ranging from the core asset-management functions to maintenance, inventory, contracts, warranties, procurement, and customer-service management. While EAM solutions have transformed the operational aspects of asset management through data capture and process automation, the decision-making process with respect to assets still heavily relies on institutional knowledge and anecdotal insights. Analytics-driven asset management is an approach that makes use of advanced analytics and optimization technologies to transform the vast amounts of data from asset management, metering, and sensor systems into actionable insight, foresight, and prescriptions that can guide decisions involving strategic and tactical assets, as well as customer and business models.

Bookmarks Related papers MentionsView impact

Research paper thumbnail of InEDvance: Advanced IT in Support of Emergency Department Management

Emergency Departments (ED) are highly dynamic environments comprising complex multi-dimensional p... more Emergency Departments (ED) are highly dynamic environments comprising complex multi-dimensional patient-care processes. In recent decades, there has been increased pressure to improve ED services, while taking into account various aspects such as clinical quality, operational efficiency, and cost performance. Unfortunately, the information systems in today’s EDs cannot access the data required to provide a holistic view of the ED in a complete and timely fashion. What does exist is a set of disjoint information systems that provide some of the required data, without any additional structured tools to manage the ED processes. We present a concept for the designof an IT system that provides advanced management functionality to the ED. The system is composed of three major layers: data collection, analytics, and the user interface. The data collection layer integrates the IT systems that already exist in the ED and newly introduced systems such as sensor-based patient tracking. The analytics component combines methods and algorithms that turn the data into valuable knowledge. An advanced user interface serves as a tool to help make intelligent decisions based on that knowledge. We also describe several scenarios that demonstrate the use and impact of such a system on ED management. Such a system can be implemented in gradual stages, enabling incremental and ongoing improvements in managing the ED care processes. The multi-disciplinary vision presented here is based on the authors’ extensive experience and their collective records of accomplishment in emergency departments, business optimization, and the development of IT systems.

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Research paper thumbnail of Shift Scheduling for Third Level IT Support: Challenges, Models and Case Study

Outsourcing IT support of an enterprise requires that third level IT support is provided as a ser... more Outsourcing IT support of an enterprise requires that third level IT support is provided as a service by the outsourcer. Although there is a large body of existing work regarding demand forecasting and shift schedule creation for various domains such as call centers, very little work exists for third level IT support. Moreover, there is a significant difference between such

Bookmarks Related papers MentionsView impact

Research paper thumbnail of Efficient Processing of Uncertain Events in Rule-Based Systems

IEEE Transactions on Knowledge and Data Engineering, 2012

There is a growing need for systems that react automatically to events. While some events are gen... more There is a growing need for systems that react automatically to events. While some events are generated externally and deliver data across distributed systems, others need to be derived by the system itself based on available information. Event derivation is hampered by uncertainty attributed to causes such as unreliable data sources or the inability to determine with certainty whether an event has actually occurred, given available information. Two main challenges exist when designing a solution for event derivation under uncertainty. First, event derivation should scale under heavy loads of incoming events. Second, the associated probabilities must be correctly captured and represented. We present a solution to both problems by introducing a novel generic and formal mechanism and framework for managing event derivation under uncertainty. We also provide empirical evidence demonstrating the scalability and accuracy of our approach.

Bookmarks Related papers MentionsView impact

Research paper thumbnail of A Methodological Framework for Business-Oriented Modeling of IT Infrastructure

Bookmarks Related papers MentionsView impact

Research paper thumbnail of Calculating the Business Importance of Entities in a Service-Oriented Enterprise

Component business modeling (CBM) serves as a powerful analytical framework for reasoning about t... more Component business modeling (CBM) serves as a powerful analytical framework for reasoning about the business as a set of business components that collaborate through the provision and consumption of business services. This paper proposes and illustrates a method to calculate the relative importance of the entities that make up a componentized enterprise architecture. The proposed method includes a formal definition

Bookmarks Related papers MentionsView impact

Research paper thumbnail of Waiting and sojourn times in a multi-server queue with mixed priorities

Queueing Systems - Theory and Applications, 2009

We consider a multi-server queue with K priority classes. In this system, customers of the P high... more We consider a multi-server queue with K priority classes. In this system, customers of the P highest priorities (P<K) can preempt customers with lower priorities, ejecting them from service and sending them back into the queue. Service times are assumed exponential with the same mean for all classes. The Laplace–Stieltjes transforms of waiting times are calculated explicitly and the Laplace–Stieltjes transforms of sojourn times are provided in an implicit form via a system of functional equations. In both cases, moments of any order can be easily calculated. Specifically, we provide formulae for the steady state means and the second moments of waiting times for all priority classes. We also study some approximations of sojourn-time distributions via their moments. In a practical part of our paper, we discuss the use of mixed priorities for different types of Service Level Agreements, including an example based on a real scheduling problem of IT support teams.

Bookmarks Related papers MentionsView impact

Research paper thumbnail of Creating operational shift schedules for third-level IT support: challenges, models and case study

International Journal of Services Operations and Informatics, 2008

Bookmarks Related papers MentionsView impact