[otrs] Service selection usability

Hi every one. Any one tryed to improve usability of service selection? here is my issue: When agent creating ticket via phone (mail) After setting t customer? agent can set service assigned to customer. In my department we have more tha 250 service, so process of selection became very annoying. Agent need to scroll drop box with over than 250 services and sub-services, and find correct one. Is there any possibility to improve it? e.g. On step 1 we can select only "Level 1" services. When it done we can select sub-services etc. -- Best regards & bla bla bla.... ©