When it comes to outsourcing your IT support, there are two options. You can sign and IT services SLA or you can have an ad hoc agreement with the IT support company. Which do you choose?
Ad hoc IT services
This is typically the best option for a small company that does not often need to have a problem solved. It might be because you know something about computers and can solve most of your own problems or it could be that your IT system is not all that complex and hardly ever gives trouble.
This is the arrangement usually taken by a company that has a lot of computer software and hardware to maintain. As the amount of equipment you have increases, the chances of something going wrong increases. it becomes troublesome having to contact an IT outsourcing company and have them send out a technician when one is available. The problem often has to be fixed immediately. As an IT services SLA client, you would automatically get preference over an ad hoc client.
The question is not whether an IT services SLA is a good idea, but rather when is it almost necessary. The answer to the question will depend on how often you use IT support services. If you find that you use vastly varying amounts of support over a month, then an SLA is not necessarily the best plan. Especially if those support calls are infrequent. The more frequently you need IT support, the more beneficial an IT services SLA becomes. There would also be the option to have an IT services SLA and, when the hours have been used, order ad hoc work as you need it.
There are a lot of advantages to having an IT services SLA. Take a look at how often you use IT support services and see if there is a consistent pattern. If there is, then an SLA might just be the best option for you. If you find that you often use a lot of IT support, an SLA might be the best solution.