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International Carpathian Control Conference ICCC 2002 MALENOVICE, CZECH REPUBLIC May 27-30, 2002 DEVELOPING SERVICE LEVEL AGREEMENT FOR OUTSOURCED PROCESSES AND SYSTEMS Piotr SZYMCZYK Department Control Systems, University Mining and Metallurgy, Kraków, Poland, Abstract: Service-level agreements (SLAs) are critical factors in outsourcing. The SLAs parameters and quality define the nature the services. SLAs are the means for ongoing tracking and managing the vendor's performance against service levels. The SLA details the specific operating and support requirements for each service provided. The SLA identifies each metric, which the vendor's performance will be measured. This paper presents recommended strategies, tactics and best practices to guide users in developing SLAs. In this article are also suggested a content outline for a generic SLA document. Key words: SLA, Service Level Agreements. 1 Introduction SLAs are documents that specify exactly what services the vendor will provide, how much the customer will pay, and what will happen when things go wrong. SLAs were born along with the trend toward outsourcing any services. SLAs are just what their name implies: agreement between the customer and the vendor as to the services to be provided by the vendor, and the measurable level those services that the vendor is expected to archive. Thing how an SLA might be written for commercial janitorial services, a service that is commonly outsourced. It might contain a description what will be cleaned (the services) and how frequently, and during what hours (the service level). SLAs are not typically standalone contract, but rather tend to be exhibits or attachment to a more general agreement contains boilerplate and other terms and condition. As attachment, they are as legally binding as the rest the contract. A good SLA will describe a service in great detail be answering the following question [Kaye 2002]: What exactly is the service to be provided? 605 2 Building SLA What are the responsibilities with regards to this service? How will the quality the service be measured? What is the service level the vendor is expected to achieve? How will performance be reported? What corrective action will the vendor take it if the service levels are not achieves? What fees will the customer pay for the service? What financial remedies will be used to compensate the customer when the service levels are not archives? The SLA agreement defines precisely the level rendered service. It consists many elements, for each them separately defining individual SLA. It is also possible to define so called collective SLA consisting many elements, and then one should define the influence particular elements on resulting SLA. An agreement this type explicitly defines a service type, giving its range and explicit type identification. In order to avoid ambiguous interpretations the agreement it is necessary to introduce definitions standards and terms connected with a particular type service. It is also necessary to define precisely ways measurement, used tools measurement and also ways calculating measured values when such operations are necessary. The next SLA element is a service specification in which it can be defined, shown or compared. Main SLA elements are definitions permissible fluctuation the previously defined parameters which establish a usual fluctuation from an ideal state accepted by parties the agreements as a typical phenomenon connected with a particular parameter- it can be related to a physical character a given parameter. The other main SLA element is a precise service definition in a ways permitting for verifying this level and establishing if a particular service is rendered on the assessed level. For SLA agreement correct functioning it is necessary to give criteria service level measurement. Next in SLA agreement there are defined types and amount fines for not keeping service levels, exceptions referring to exclusions and liability limitations. An important element is establishing a service price (they can be values defining unit values, packets or whole values), ways cycle settlements settling and the similar. An important element SLA agreement is the part referring to documents (document pattern service report, protocols, questionnaires), procedures connected with its realization (including instructions for usual and exceptional situations). Next elements SLA agreement are an optional character and if parties have a will, they can define them precisely or not. The element group comprises defining the technology service realization, technological service (description people engaged in its realization). A good habit is to define connections a given service with other types service included in SLA agreement and these, which are not realized on the base such agreements. While an SLA should give you some degree confidence, the document itself cannot perform the service. It is just a piece paper. The way SLA creation, described above, can be summarised in a table defining SLA elements: 606 Table 1. SLA elements [Hawkins 1997] SLA element Description Service definition Description service with a precise definition its range and explicit identification its type Definition standards and termsprecise definition standard and terms from a related to a given service given field which will be used in relation to the service Measurement ways Description measurement ways, the used installations, ways calculations and statistics and results interpretation Service specification Parameters connected with a given service-in which it can be defined/ expressed/compared (for example, speed, quantity, frequency) Quality parameters Description quality parameters- what the quality level defines (for example, access, reaction time) Permissible fluctuation Permissible parameters fluctuation, permissible as a typical for a given quality and/ or for a given service level (for example, number lost packages, permissible waiting time) Service level Definition client s interesting service level (access) Service level measure criteria Description verification way a given service level Technology Description technological solutions including redundancy, excessiveness, scalability, producer Technological service Education, experience, knowledge, certificates Fines for not keeping service level Description fine types and amount for not Liability limitations, a definition exceptions and exclusions Procedures, processes, instructions for usual and exceptional situations Patterns documents Connections with other types service Remarks and other information Prices keeping a defined level Description situations without fines (for example, an operator, not we, is responsible for a given problem) Description procedures, processes, etc. connected with a particular type service Patterns writing letters, documents related to a given service (service reports, questionnaires) Explanation if and why a given type if service is related to another type service (it can not be present only when another type service appears) Other information and remarks not included in other points study Unit and packet prices SLAs we can divide into three categories: Performance SLAs, Reactive SLAs, and Proactive SLAs. 607 Performance SLAs are those that address ongoing services. These SLAs set the quality these services based on objective measurement and a baseline values that establish acceptable service level. One issue that must be dealt with in any performance SLA is control. Typical Performance SLAs for Web Hosting services include: Uptime and performance services Connectivity Content delivery and caching Reactive SLAs are based on the vendor s reaction to events, and the principal measurement is time. There are two important issues that are fundamental to all reactive SLAs: the classification incidents, and the extend to which the vendor is directly responsible for the resolution problems. Incidents should be classified according to two attributes: severity and priority. Severity is a property the problem, while priority is a property the solution. Incident Classification by Severity: Critical (service is down or performance has become unacceptable) Urgent (service is operating normally but a redundant component or supporting feature has failed) Routine (service is available and performance adequately but there are other problem) Typical Reactive SLAs for Web Hosting services include: Response time Resolution s Recoveries Response to security threats Proactive SLAs includes those that describe services that are intended to prevent problems from occurring in the first place. Typical Proactive SLAs for Web Hosting services include: Monitoring Backup Audits Installation patches and upgrades DNS Performance analysis and tuning Capacity analysis and planning 608 3 Example SLA Target Site Server Network SLA Commit-ment Content Response times Table 2. Example SLA [SLA 2001] Metric Collection Acceptable Notification Measurement Ranges Commitment Method High/Low Time/Method Percen- Ping URL 100%/98% 15 minutes/ tage N. No limit Simulated transaction executed from within DC Site hits Number Negotiated Backup Success/ Report execution Transaction volumes Backup deploy new servers/ provision Speed Network latency Number Number users in 15 minutes - via cumulative Web server logs or load Success/ Time (hours, days) Sitespecific Milliseconds Milliseconds 8 seconds/ 1 second No Resolution Commitments Milliseconds 15 minutes/ & paging Daily/ / & paging balancers Ping server 100%/98% minutes/ Report execution Execute Expansion site - based on contracted times Negotiated - usually less than No Daily/ Execute 10 days/ 1 day Ping Negotiated 5 minutes/ Network 120 milliseconds/ min. - monitor if violated for edge-to-edge 80 milliseconds more than round trip 15 minutes / Less than 609 Database Application Load Balance Infrastructure management increase capacity Backup to network Backup deploy new Number infrastructure -re allowed in a month Number content allowed in a day Load testing availability Reports shared upgrade Success/ Days/ hours Success/ Days/ hours Number Number Aggregated ping results Ping database Report execution Ping or call to port application Report execution 100%/98% 15 minutes/ 10 days/ 1 day Less than No Daily/ Execute 100%/98% 15 minutes/ Ping 100%/98% 15 minutes/ Report No Daily/ Execute 10 days/ 1 day Unlimited/ 10 No limit Available/ Not avail. Unlimited reports/ No reports Hours/ 5 days/ days References HAWKINS S. 1997: Service-Level Agreement for Outsourcing, Strategic Analysis Report, Gartner Group 1997, KAYE D. 2002: Strategies for Web Hosting and Managed Services, Willey SLA 2001: SLA Report, Meta Group 2001, 610
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