Showing papers on "Service level published in 2002"

Capacity reliability of a road network: an assessment methodology and numerical results

Abstract: Existing reliability studies of road networks are mainly limited to connectivity and travel time reliability and may not be sufficient for a comprehensive network performance measure. Recently Chen et al. (J. Adv. Transp. 33 (2) (1999) 183–200) introduced capacity reliability as a new network performance index. It is defined as the probability that the network can accommodate a certain traffic demand at a required service level, while accounting for drivers' route choice behavior. The proposed capacity reliability index includes connectivity reliability as a special case and also provides travel time reliability as a side product. This paper extends the capacity reliability analysis by providing a comprehensive methodology, which combines reliability and uncertainty analysis, network equilibrium models, sensitivity analysis of equilibrium network flow and expected performance measure, as well as Monte Carlo methods, to assess the performance of a degradable road network. Numerical results are also provided to demonstrate the feasibility of the proposed framework.

SNAP: A Protocol for Negotiating Service Level Agreements and Coordinating Resource Management in Distributed Systems

Abstract: A fundamental problem in distributed computing is to map activities such as computation or data transfer onto resources that meet requirements for performance, cost, security, or other quality of service metrics. The creation of such mappings requires negotiation among application and resources to discover, reserve, acquire, configure, and monitor resources. Current resource management approaches tend to specialize for specific resource classes, and address coordination across resources only in a limited fashion. We present a new approach that overcomes these difficulties.We define a resource management model that distinguishes three kinds of resource-independent service level agreements (SLAs), formalizingag reements to deliver capability, perform activities, and bind activities to capabilities, respectively. We also define a Service Negotiation and Acquisition Protocol (SNAP) that supports reliable management of remote SLAs. Finally, we explain how SNAP can be deployed within the context of the Globus Toolkit.

System and method to assure network service levels with intelligent routing

Abstract: A method and system for maintaining a traffic service level for data communicated by a computer network having a source (USER1). The computer network is connected to at least one of many networks (82), where each of the many networks includes a number of paths (86) for transporting the data communicated to a destination (USER2, USER3). In one embodiment to the method, the traffic service level associated with one of the paths (86) between the source (USER1) and destination (USER2, USER3) is monitored. Then, it is determined whether the traffic service level associated with that path (86) meets one or more performance metrics. If a flow of data communicated over the monitored path (86) fails to meet at least one of the performance metrics, then a service level violation is indicated. Upon such an indication, an alternate path is selected to resolve the service level violation.

Method, system, and program for determining a modification of a system resource configuration

Abstract: Provided are a method, system, and program for managing multiple resources in a system at a service level, including at least one host, network, and a storage space comprised of at least one storage system that each host is capable of accessing over the network. A plurality of service level parameters are measured and monitored indicating a state of the resources in the system. A determination is made of values for the service level parameters and whether the service level parameter values satisfy predetermined service level thresholds. Indication is made as to whether the service level parameter values satisfy the predetermined service thresholds. A determination is made of a modification to one or more resource deployments or configurations if the value for the service level parameter for the resource does not satisfy the predetermined service level thresholds.

Supply chain collaboration alternatives: understanding the expected costs and benefits

Abstract: Collaboration is a recent trend in supply chain management (SCM) that focuses on joint planning, coordination, and process integration between suppliers, customers, and other partners in a supply chain. Its competitive benefits include cost reductions and increased return on assets, and increased reliability and responsiveness to market needs. Recent advances in inter‐enterprise software and communication technologies, along with a growing use of strategic partnering and outsourcing relationships, has resulted in a confusing assortment of alternative information systems approaches for supporting collaborative SCM. This paper analyzes the alternatives and presents a framework for understanding the expected costs and benefits of each type of system. These costs include not only the total cost of ownership of the system, but also the partnership opportunity cost – the cost of being tied to a partner due to system inflexibility. The benefits of collaborative SCM include process, inventory, and product cost reductions as well as increased cycle times, service levels, and market intelligence.

The impact of information sharing and ordering co‐ordination on supply chain performance

Abstract: This paper presents a study on the impacts of information sharing and ordering co‐ordination on the performance of a supply chain with one capacitated supplier and multiple retailers under demand uncertainty. In particular, a computer model is proposed to simulate inventory replenishment decisions by the retailers and production decisions by the supplier under different demand patterns and capacity tightness. It is found that information sharing and ordering co‐ordination significantly impact the supply chain performance in terms of both total cost and service level. It is also found that the value of sharing information and ordering co‐ordination is significantly affected by demand patterns and capacity tightness. Guidelines are developed for companies to share information and co‐ordinate orders under different conditions. These guidelines can help companies reduce costs and improve customer service levels in the supply chain.

A system for global and local data resource management for service guarantees

Abstract: An end-to-end content management and delivery architecture is disclosed which provided for end-to-end content management from a data storage facility to an requestor (5) remotely located. An End-to-End Content I/O Management (ECIM) contains a Global Infrastructure Control (GIC) (4) that monitors the composite load levels at data centers (1, 2, and 3) across network servers, and identifies the best data center from which content request is met. Each data center has a QoS enforcer that monitors content arriving at the data center and controls the entry of all traffic at the data center. Each data center also has a controller, which controls the end-to-end I/O in the local data center. The ECIM allows end-to-end control of the content delivery, scalability provisioning of the application content storage pool to meet service level agreements; dynamic load balancing of the content, and optimization of the I/O resources both locally and across data centers (1, 2, and 3) so as to maximize the service level guarantees with minimum resource usage from application servers to storage.

G-QOSM: Grid Service Discovery Using QoS Properties

Abstract: We extend the service abstraction in the Open Grid Services Architecture~\cite{ogsa} for Quality of Service (QoS) properties. The realization of QoS often requires mechanisms such as advance or on-demand reservation of resources, varying in type and implementation, and independently controlled and monitored. Foster et al. propose the GARA~\cite{FostKessl99} architecture. The GARA library provides a restricted representation scheme for encoding resource properties and the associated monitoring of Service Level Agreements (SLAs). Our focus is on the application layer, whereby a given service may indicate the QoS properties it can offer, or where a~service may search for other services based on particular QoS properties.

Financial modeling and counseling system

Abstract: The present invention relates to a financial management system for providing personalized financial advice to a user (110). The system operates in a collaborative computing environment between the user and a financial advisor (106) and comprises a service level subsystem and an advice generating subsystem (102). The service level subsystem allows the user to negotiate a service level agreement that defines the user's desired level of support and limits access to user provided information. The advice generating subsystem is coupled to the service level subsystem and includes one or more coaching engines that dynamically analyze the financial needs of the user in accordance with the user's service level agreement. Furthermore, the coaching engine provides customized financial advice tailored to the user's life intentions.

Inventory-Service Optimization in Configure-to-Order Systems

Abstract: This study is motivated by a process-reengineering problem in personal computer (PC) manufacturing, i.e., to move from a build-to-stock operation that is centered around end-product inventory towards a configure-to-order (CTO) operation that eliminates endproduct inventory. In fact, CTO has made irrelevant the notion of preconfigured machine types and focuses instead on maintaining the right amount of inventory at the components. CTO appears to be the ideal operational model that provides both mass customization and a quick response time to order fulfillment. To quantify the inventory-service trade-off in the CTO environment, we develop a nonlinear optimization model with multiple constraints, reflecting the service levels offered to different market segments. To solve the optimization problem, we develop an exact algorithm for the important case of demand in each market segment having (at least) one unique component, and a greedy heuristic for the general (nonunique component) case. Furthermore, we show how to use sensitivity analysis, along with simulation, to fine-tune the solutions. The performance of the model and the solution approach is examined by extensive numerical studies on realistic problem data. We present the major findings in applying our model to study the inventory-service impacts in the reengineering of a PC manufacturing process.

A Survey of Policy Specification Approaches

Abstract: Policies are rules governing the choices in behaviour of a system. They are often used as a means of implementing flexible and adaptive systems for management of internet services, distributed systems, and security systems. There is also a need for a common specification of security policy for large-scale, multiorganisational systems where access control is implemented in a variety of heterogeneous components. In this paper we survey both security and management policy specification approaches. We also cover the issues relating to detecting and resolving conflicts which can arise in the policies and some ideas on how to refine high level goals and service level agreements into implementable policies. The paper briefly outlines some of the research issues that have to be solved for large-scale adoption of policy-based systems

On service level agreements for IP networks

Abstract: Many corporate WAN architects are considering migrating from costly leased line circuits to 'private IP' services. In order to do so IP service providers must provide service level agreements (SLA) that offer robust assurances that cover service availability and performance. The industry direction is to model IP SLA after those offered by frame relay networks. The reality however is that the SLA surrounding today's private IP services only loosely mirror frame relay SLA. In this paper, we examine the intent and limitations of current IP SLA. We explore the feasibility of two significant enhancements. First we study the feasibility of reducing the time scales associated with the performance assessment to something that is meaningful to the corporate end user. Second we explore the potential benefits of extending current performance assessment methods with application level performance metrics. We present preliminary results suggesting that it is possible to offer performance assurances based on carefully chosen latency objectives as long as the average utilization of the access link is less than 50% over time scales identical to those used by the performance metrics. We introduce a Web-oriented performance metric (the Web Response Time metric) and show promising benefits over traditional ping based metrics. However, for either ping or Web-based performance metrics, due to the inherent nature of a best-effort IP service, IP performance assurances are only practical when applied over long time scales.

On the (S-1, S) lost sales inventory model with priority demand classes

Abstract: In this paper an inventory model with several demand classes, prioritised according to importance, is analysed. We consider a lot-for-lot or (S - 1, S) inventory model with lost sales. For each demand class there is a critical stock level at and below which demand from that class is not satisfied from stock on hand. In this way stock is retained to meet demand from higher priority demand classes. A set of such critical levels determines the stocking policy. For Poisson demand and a generally distributed lead time, we derive expressions for the service levels for each demand class and the average total cost per unit time. Efficient solution methods for obtaining optimal policies, with and without service level constraints, are presented. Numerical experiments in which the solution methods are tested demonstrate that significant cost reductions can be achieved by distinguishing between demand classes.

The structure and management of service level agreements in networks

Abstract: The paper proposes a structure for quality-of-service (QoS)-centered service level agreements (SLA), and a framework for their real-time management in multiservice packet networks The SLA is structured to be fair to both parties, the service provider and their customer The SLA considered here are for QoS assured delivery of aggregate bandwidth from ingress to egress nodes; however, the control and signaling is for the more granular flows or calls A SLA monitoring scheme is presented in which revenue is generated by the admission of flows into the network, and penalty incurred when flows are lost in periods when the service provider is not SLA compliant In the SLA management scheme proposed, the results of a prior off-line design are used, in conjunction with measurements taken locally at ingress nodes, to classify the loading status of routes The routing and resource management are based on virtual partitioning and its supporting mechanism of bandwidth protection The effectiveness of SLA management is measured by the robustness in performance in the presence of substantial diversity in actual traffic conditions A simulation testbed called D'ARTAGNAN has been built from which we report numerical results for a case study The results show that the SLA management scheme is robust, fair and efficient over a broad range of traffic conditions

Opus: an overlay peer utility service

Abstract: Today, an increasing number of important network services, such as content distribution, replicated services, and storage systems, are deploying overlays across multiple Internet sites to deliver better performance, reliability and adaptability. Currently however, such network services must individually reimplement substantially similar functionality. For example, applications must configure the overlay to meet their specific demands for scale, service quality and reliability. Further, they must dynamically map data and functions onto network resources-including servers, storage, and network paths-to adapt to changes in load or network conditions. In this paper, we present Opus, a large-scale overlay utility service that provides a common platform and the necessary abstractions for simultaneously hosting multiple distributed applications. In our utility model, wide-area resource mapping is guided by an application's specification of performance and availability targets. Opus then allocates available nodes to meet the requirements of competing applications based on dynamically changing system characteristics. Specifically, we describe issues and initial results associated with: i) developing a general architecture that enables a broad range of applications to push their functionality across the network, ii) constructing overlays that match both the performance and reliability characteristics of individual applications and scale to thousands of participating nodes, iii) using Service Level Agreements to dynamically allocate utility resources among competing applications, and iv) developing decentralized techniques for tracking global system characteristics through the use of hierarchy, aggregation, and approximation.

Autonomic provisioning of network-accessible service behaviors within a federated grid infrastructure

Abstract: Methods, systems, computer program products, and a method of doing business are disclosed for autonomically provisioning network-accessible services in a decentralized network having a federated grid infrastructure. Autonomic, grid, and web services-related technologies, standards, and concepts are leveraged. More particularly, web service behaviors (augmented as grid services, according to preferred embodiments) are autonomically provisioned (i.e., dynamically distributed) via a grid of hosting services. In preferred embodiments, this dynamic distribution occurs in response to (and as a function of) external catalysts, such as algorithms that monitor designated resources (e.g., to proactively determine when the commitments in a utility service provider's service level agreements are in jeopardy).

A service level agreement language for dynamic electronic services

Abstract: This paper proposes a novel language for Service Level Agreements (SLAs) for dynamic and spontaneous electronic services. In a cross-organizational setting, it is important for customers of a service to obtain, monitor and enforce quality of service (QoS) guarantees by service providers, usually expressed in the form of SLAs. Since the supervision and management of SLAs and the provisioning of corresponding systems should be automated for economic reasons, we need a formal language to define an SLA. If moreover, providers and customers want to sign custom-made SLAs, the SLA language, correspondingly, must provide a large degree of flexibility. The SLA language described in this paper aims at providing the needed flexibility by means of an XML-based representation and a runtime system for SLAs. Using this language, parties to a SLA can describe how parameters are measured and computed from raw metrics, the guarantees they want with respect to those parameters and the involvement of third parties to, e.g., verify independently SLA compliance.

Retail performance measures for seasonal fashion

Abstract: Retail success can be defined as achieving high gross margins and customer service levels (i.e. being in‐stock) with as little inventory as possible. Forecast accuracy, process lead‐time, offshore/local sourcing mix and up‐front/replenishment buying mix can have a significant impact on success in connection with sourcing seasonal products with a fashion content. Forecast accuracy depends on the characteristics of the product and supply lead‐time. Lead‐times are traditionally long and buying decisions are often made seven to eight months prior to the start of the selling season. Forecast errors lead to some of the items being liquidated at clearance prices while others stockout and lead to lost sales. As a result retailers often resort to higher mark‐up prices with fashion products. However, typical retail performance measures such as service level, lost sales, product substitute percentage, gross margin, gross margin return on inventory, sell‐through percentage and mark‐down rate mask the source of the problems. In this paper, we discuss these performance measures and propose a new one. Additionally, case study analysis of a group of Finnish department stores is presented.

Demand responsive services in hierarchical public transportation system

Abstract: An advanced public transportation system called the local initiative for neighborhood circulation (LINC) is proposed and the realization of its usage is investigated. LINC effectiveness and efficiency comes from its utilization of a transit-station-oriented system with elimination of present bus stops. LINC has three levels of services. Level 1 is the regional trunk line service with high-speed and high-capacity service provided by the regional transit authority. Level 2 is the intercommunity express bus service with frequent and reliable service provided by the metro transit system. Level 3 could have many forms to serve within the community and to/from level 1 or level 2 transit stations. Our study is limited to the dial-a-ride service, which operates door-to-door service as a public taxi, provided by small buses and/or vans. This paper will address the optimization problem of the dial-a-ride service. A genetic algorithm scheme is applied to its optimization and proper solutions are obtained as a result.

Using fuzzy control to maximize profits in service level management

Abstract: The growth of e-commerce is creating demand for services with financial incentives for service providers. Such services are specified by service level agreements (SLAs) in which revenue accrues with the number of completed transactions, and costs are incurred if response times go above a specified threshold. In this paper we propose a profit-oriented feedback control system that automates the admission control decisions in a way that balances the loss of revenue due to rejected work against the penalties incurred if admitted work has excessive response times. One approach to making these trade-offs is to employ classical control theory (e.g., proportional integral controllers); however, doing so requires a labor-intensive design process that tailors the controller to a specific workload and profit model. Instead, we develop a fuzzy control algorithm that implements hill climbing logic to maximize profits and handle the stochastics that make profits quite "bumpy." Our studies of a Lotus Notes® e-mail server reveal that the fuzzy controller requires little human intervention and is robust to changes in workloads and values of SLA parameters. Further, we prove that our design of the fuzzy controller leads to a value of the admission control parameter that maximizes steady state profits.

COPS-SLS: a service level negotiation protocol for the Internet

Abstract: The deployment of QoS over the Internet may achieve protocols for the negotiation of service levels, as well as mechanisms for the end-to-end realization of service level agreements. Such general-purpose protocols include Common Open Policy Service (COPS) for policy specification within a domain. This article proposes an extension of the COPS protocol for intra- and interdomain service level negotiation. The proposed protocol is known as COPS-SLS. This allows the configuration of domain policies regarding service levels, and the automatic negotiation of service levels within the domain policies.

System and method for evaluating the performance of a computer application

Abstract: A system for evaluating the performance of a computer-implemented application, wherein the performance is measured in terms of availability. The system includes a metrics data module comprising actual service level data, wherein the actual service level data can be used to determine an actual service level; a defined data module comprising defined service level data, wherein the defined service level data can be used to determine a defined service level; and a service level analysis module in communication with the metrics data module and the defined data module for calculating the actual service level and the defined service level and for comparing the actual service level to the defined service level using a grading scale defined as a function of the defined service level.

Meta-policies for distributed role-based access control systems

Abstract: In this paper meta-policies for access control policies are presented. There has been a lot of research into the various ways of specifying policy for a single domain. Such domains are autonomous and can be managed by the users or by a specific system administrator It is often helpful to have a more general policy description in order to restrict the ways in which policy can be modified. Meta-policies fill this particular role. With their help changes to policy can be made subject to predefined constraints. Meta-policies are long lived and so can provide users with stable information about the policy of the system. In addition they can provide bodies external to a domain with relevant but restricted information about its policies, so forming a basis for co-operation between domains. For example, a domain's meta-policy can function as a policy interface, thus establishing a basis for agreement on the structure of the objects accessed In this way it is possible to build service level agreements between domains automatically.

Supply chain structures : coordination, information and optimization

Abstract: 1. Introduction and Overview Jing-Sheng Song, D.D. Yao. 2. Efficient Supply Chain Structures for Personal Computers Lingxiu Dong, H.L. Lee. 3. Intrafirm Incentives and Supply Chain Performance N. Agrawal, A.A. Tsay. 4. Impact of Manufacturing Flexibility on Supply Chain Performance S. Biller, et al. 5. The Use of Demand Information in Supply Chain Management G. Gallego, O. Ozer. 6. Supply Chain Information Sharing in a Competitive Environment Lode Li, Hongtao Zhang. 7. Planning and Scheduling in an Assemble-To-Order Environment N.J. Vandaele, M.R. Lambrecht. 8. Network Server Supply Chain at HP: A Case Study D. Beyer, J. Ward. 9. Inventory Allocation at a Semiconductor Company A.O. Brown, et al. 10. Leadtime, Inventory, and Service Level in ATO Systems Yashan Wang. 11. Dependence Analysis of Assemble-to-Orders Systems S.H. Xu. 12. Sequences of Multi-Item Demands J.W. Mamer, S.A. Smith.

Automatic enforcement of service-level agreements for providing services over a network

Abstract: The invention deals with the enforcement of Service Level Agreement for the services provided over a client-server network. The invention discloses a method, system and a program product for automatic enforcement of SLAs. This is achieved by automatic metering of requests for service and allocation of resources of the server based on the SLA, current available resources and the needs of the customer.

Service monitoring and reporting system

Abstract: A system and method for detecting or reporting service level or service outages on a network includes a meta service generator that operates on a network inventory to generate service definitions. The system is a server-based model, and each service definition includes usergroup and points of presence, thus instantiating multiple services in a manner that allows the definition to focus on relevant element events amid massive network event data, and detect service outages quickly and dependably. The outages, transaction spec outages and events so determined may be aggregated to provide overall measures that are compared with thresholds, performance criteria and other service metrics specified in a user Service Level Agreement (SLA) for billing, credit, evaluation or other purposes. Batch processing embodiments may operate with outage logs, and employ a concurrence algebra to correct outage intervals for planned and forced outages, providing a truer measure of performance that allows the system to generate multiple different reports reflecting different compensable or inconsequential outage states.

System and method for managing requests for medical transportation

Abstract: A call center for handling requests for medical transportation utilizes a system that assists a call center agent by automatically determining, or prompting the agent to ask for, all information needed to assess the level of service required and the effects of any applicable contractual provisions. The system captures information relating to the patient and the requested transportation, and applies service level rules representing the applicable regulatory requirements for medical transportation at the location of the patient to determine the required level of service based on the patient's condition and needs. The system further applies business rules representing the contractual provisions that are applicable to the requested transportation to determine responsibility for the cost of transportation, the authority of the requester to change the level of service or other aspects of the transportation, and the responsibility for the cost of transportation in the event that an aspect of the transportation has been changed.

Coordinating Replenishment and Pricing in a Firm

Abstract: Replenishment and pricing strategies are traditionally determined by entirely separate units of a firm, the former by production and the latter by marketing. In a large organization production and marketing are traditionally measured in terms of performance criteria appropriate and relevant within the world in which they operate, rather than in terms of overall company performance. We consider a situation where the headquarters uses a simple linear transfer price between the two functions to govern the transactions. The misaligned incentives among these functional managers are caused by a transfer price between them that distorts the marginal production cost and revenue, as well as by a misallocation of cost: Marketing's pricing strategy influences expected leftover inventory, but only production incurs the cost. The misalignment can be mitigated through the following two ways. First, if production commits to a service level instead of an inventory level, both production and marketing, and hence the firm as a whole, are better off. Second, the same improvement can be achieved through organizational changes so that marketing becomes the dominant function. We also propose a mechanism that aligns the functional managers' incentives to be compatible to the firm.