In order to honor a service level agreement a system must first pass an acceptance test which demonstrates that the service levels are achieved. Thereafter upgrades must be scheduled to keep the system within the service levels.
The following table illustrates rates for providing specific service levels for a small business with 10 or fewer computers.
|Percent Uptime||Downtime||Rate per month|
|97%||1 day per month||$ 480.00|
|99.9%||45 minutes per month||$ 600.00|
|99.99%||1 hour per year||$ 1,000.00|
|99.999%||5 minutes per year||$ 5,000.00|
|99.9999%||5 minutes per decade||$ 10,000.00|
Uptime is just one service level. Every system has a set of primary services which should have one or more service levels each. A primary service is a deliverable of a system to a business that if it becomes unavailable defines the system to be in a failed state. It doesn't matter if the lights are flashing or the network is up. The system has failed. An adjustment to the system is required to put it back into an conforming state or within the service level agreement. Some service levels are easy to state but hard to achieve. A typical service level in this category is response time. Response time is usually measured from the time a user initiates a transaction to the time the system completes it.
For example; a response time of 5 seconds may be stated where every transaction can be completed in 5 seconds. However in practical systems this is an unreasonable requirement. Specific transaction types vary widely in the quantity of system resources that they require. So transactions are categorized as short, medium and long where only medium transactions are required to take less than 5 seconds. Short transactions take less than one second and long transactions can take up to 15 seconds. This type of negotiation allows a system to achieve practical requirements.
The following are a candidate list of small system primary services and their service levels.
|Primary Service||Service Level||Values||Notes|
|Network Access||Average Bandwidth, Availability||700kbps, 99%||Very few network service providers will agree to a service level other than maximum bandwidth.|
|Post to Accounts Receivable||Response Time||1 second||As an accounting system fills with data the response times increase according to the scaleability of the application. For a robust design the response time should not change much. Otherwise the hardware would have to be upgraded to maintain the service level.|
|Print Invoices||Print time||50 Invoices per minute||This is driven by printer speed, number of printers, ability of application to use multiple printers and affect of system load on print file generation|
A concise Service Level Management Proposal will begin the dialog of establishing how the IT in your company will be made and kept effective for your employees.
A Service Level Agreement will be the guiding document for establishing what must always be true about your IT systems.
Periodic Statements of work will define specific tasks for the client and Service Level provider to accomplish to keep the systems operating at target levels.
Monthly invoices will identify specific tasks performed by the Service Level provider including recurring costs, penalties and rewards.
In case you are wondering where your company fits in the grand scheme of Service Level Management, COBIT devised the following table to allow companies to self evaluate how mature they are regarding the management of service levels.
|0||Nonexistent||Management has not recognized the need for a process for defining service levels.|
|1||Initial/ad hoc||There is an awareness of the need to manage service levels, but the process is informal.|
|2||Repeatable and intuitive||There are agreed-upon service level agreements, but they are informal and not revised. Service level reporting is incomplete.|
|3||Defined process||The service level agreement process is in place with checkpoints for reassessing service levels and customer satisfaction.|
|4||Managed and measurable||Performance measures are increasingly reflecting end-user needs, rather than only IT goals.|
|5||Optimized||Service levels are continuously reevaluated to ensure alignment of IT and business objectives.|