We have SOI 3.3, APM 10.0, spectrum 10.1.1 and Servicedesk 14.1.
Spectrum 10.1.1 is used to create models in SO I3.3.
SOI 3.3 is integrated with APM 10.0 for depiction of business transaction.
Servicedesk 14.1 is integrated with SOI 3.3 for auto ticket creation.
Can I upgrade SOI from 3.3 to 4.2 as it has reached end of support.? Do I need to upgrade any other tool along with SOI ?
You can upgrade from SOI 3.3 CU2 to CA SOI 4.2. Its documented in CA SOI document here:
Upgrade CA SOI - CA Service Operations Insight - 4.2 - CA Technologies Documentation
For integrated domain versions and their connectors, have a look at compatibility matrix:
CA Service Operations Insight Connectors - CA Technologies