Service Level Agreement in a WEB FARM : LUSENET : Service Level Management : One Thread

I'm challenged to write down a SLA for my web farm, that will be outsourced next month. My outsourcer said the service availability of 99.50% is too high. Where may I find out document with experience, metrics and template in order to benchmark Reliability, Availability and Serviceability?

-- amy lowell (, January 03, 2002


Dear Amy

I'm not entirely sure what you are asking here Amy. I would look at (while pretending to be a prospective customer) other web farm companies' offerings. They should give you a good idea what their claims and expectations are. Also, many will have some form of either an SLA or contract document which will define the deliverables - basically what your paying for - uptime, backup etc. Hope this helps!


-- Andrew Lockhart (, January 06, 2002.

Thanks for your contribute. Could you suggest me any companies offerings this type of service, in order to find out SLA and related documents, possibly available in internet?

-- amy lowell (, January 07, 2002.

Amy, Andy had some good suggestions. As always, part of the answer is that to give a detailed answer, we need more details about your environment. However, with that as a disclaimer, I will suggest that you ask your soon-to-be service provider to give you statistics about availability for some of their other clients. Admittedly, they can bias the information by being selective in the data they choose to presesnt., but it is another point of reference. Availability of 99.5% equates to approximately 7 minutes of downtime per day, or about 3.6 hours/month.

It is not a question of whether or not 99.5% is technically feasible. It is. It is a question of whether or not it is feasible within your outsourcer's architecture. Also, there are the simple issues of hedging by them to minimize their exposure.

This begs another question - penalties. What are going to be the consequences of failing to meet their service level guarantee? Regarding this issue, you might want to check out the following article that I wrote on this topic:

Good luck. Feel free to contact me directly if you wish.

Rick Sturm

-- Rick Sturm (, January 10, 2002.

Amy, consider the availability requirements from the business perspective. The actual business requirements should drive the support solutions and associated costs.

Cost could be influencing the outsourcer's current position.

Wiley Vasquez

-- Wiley Vasquez (, January 16, 2002.

Its not a matter if its technically possible, but rather can the customer (Amy) afford to pay the associated price of delivering the service.

The SLA will (or should) be a compromise between what is acceptable from a customers business perspective, and the what the customer is prepared to pay. Some place near the middle are (hopefully) workable grounds.

If the service is business critical and extra-ordinary high availability is required, this will reflect in the service charges for such high requirements - as capable hardware, O/S, applications, data links & staff are required. 99.5% availability represents 43hours down time per year.

-- Andrew (, July 01, 2004.

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