e-Business: Organizational and Technical Foundations by Michael P. Papazoglou

Author:Michael P. Papazoglou
Language: eng
Format: mobi
Publisher: Wiley
Published: 0101-01-01T00:00:00+00:00

software deployment capabilities that automatically identify and solve distribution and configuration problems

software modules that automatically manage software reliability after deployment

software management systems that rapidly expand to cover new software technologies

A Service-Level Agreement is an important and widely used instrument in the maintenance of service provision relationships that ensures a guaranteed level of performance is delivered. Where contracts are clearly defined and closely monitored in order to guarantee adherence of all involved parties to the terms agreed upon, then participants are protected by the SLA. An SLA is basically a performance guarantee typically backed up by charge-back and other mechanisms designed to compensate service clients and to force enterprises to fulfill contractual commitments. Both service providers and clients alike need to utilize SLAs in order to work well together.

A service level agreement is a contract between a service provider and a client that specifies, usually in measurable terms, what services the service provider will furnish. It defines mutual understandings and expectations of a service between the service provider and service consumers. The service guarantees are about what transactions need to be executed and how well they should be executed. An SLA may have the following components: purpose – describing the reasons behind the creation of the SLA; parties – describes the parties involved in the SLA and their respective roles (provider and consumer); validity period – defines the period of time that the SLA will cover. This is delimited by start time and end time of the term. An SLA also has a scope that defines the services covered in the agreement, restrictions that define the necessary steps to be taken in order for the requested service levels to be provided, and service-level objectives, which are the levels of service that both the users and the service providers agree on, and usually include a set of service-level indicators, like availability, performance and reliability. Finally, an SLA also specifies penalties in case the service provider underperforms and is unable to meet the objectives in the SLA.

To better understand requirements when entering into an e-Business application SLA, one needs to address several important concerns. These include: the levels of availability that are needed for an application; whether the business can tolerate application downtime and how much; whether there is adequate redundancy built in so that services can be offered in the event of a system or network failure; the transaction volumes expected of e-Business applications and services; whether underlying systems have been designed and tested to meet these peak load requirements and, finally, how important are request/response times.

SLAs are, in conjunction with security policies, reviews of security procedures, staff qualifications and so on, one of the most effective means of dealing with QoS. One important function that an SLA should address is the QoS at the source. This refers to the level of service that a particular service provides [Mani 2002]. QoS is defined by important functional and nonfunctional service quality attributes, such as service metering and cost, performance metrics (e.g. response time), security attributes, (transactional) integrity, reliability, scalability, and availability.

Download

Copyright Disclaimer:
This site does not store any files on its server. We only index and link to content provided by other sites. Please contact the content providers to delete copyright contents if any and email us, we'll remove relevant links or contents immediately.