Hi Bart

What we do is think about what the ticket is about and start to combine all the SR categories and IR Categories all in one place. Then when you do your reporting you can filter out the SR’s and IR’s from the filters…. (Because the categories are only there for reporting purposes...)
 

Remember that all your requests from the portal will need a category, they do not need to be a different category because when reporting you can report on the  request type and not the category. 

Then main to get right is pick you categories generic enough so that you do not have to keep editing them, so think of them more of a service than a product… Email is fine, unless you have more than one email system. can you just use VPN issue or do you need to go granular into the multiple VPN products you might have.. it really depends on what you want to report on so best to start thinking about what you want to report on regarding categories. 

You can structure it as the overall topic on the first level, for example Email, Network, Application Access. On the second level, split it into general types or parts of that topic. For Network, it would be something like Wi-fi, VPN etc. The third level can then be the specific issues/symptoms that you might face there. For example, Wi-fi might have issues like router failure, low speeds, dropping connections. For requests, you would use the third level to mention the different types of requests as well. You need to think of it from the perspective of what kind of reporting you need but keep it easy enough for your Agents to be able to find the right item.

You can also look at using Custom Objects and Workflows to automatically assign those categories for Service Items.