Performance Issue after Upgrade and Installation of Oil & Gas and Utilities Add-ons

Recently I involved in a project where we need to upgrade Maximo to the latest version and install several big add-ons which include SP, HSE (which is Oil & Gas), and Spatial (which is the same as Utilities). This is the first time I see a system with that many add-ons installed. The DB in use is SQL Server.

Although we’ve done all recommended steps for the upgrade like running integrity checks before and after the upgrade; and updating statistics and rebuilt all indexes. After the upgrade, it was still a lot slower compared to the before upgrade version. To analyze the problem, I tested and compared the performance of several different queries on the WORKORDER table and the TICKET, some intended to use indexes, some intended to create a full table scan. With the queries that use more indexes, the performance gap seems to be smaller (upgraded version is 2-3 times slower); and the one which requires full table scan is significantly slower (10-20 times slower).

With that result, we concluded that the slower performance is due to