Support packages and add-ons, why are they important? in sap

1. Why do we require a support package and why it is not incorporated with the new version of SAP R/3?
2. What are add-ons and why do we require add-ons?
3. What is CRT and why we require it?
4. Who should decide which patch should be applied and when?

Support packages are a collection of fixes that have come out after the official release of an SAP software solution.

Notice, though, that some support packages are preloaded with the system. R/3 Enterprise SR1 is a good example of that.

An add-on is a component that can be loaded into an SAP software solution.
Examples: PI, PI_BASIS, SOA 1.0 (CGVMIC).
The CGVMIC is the Management of Internal Controls add-on, which is part of the Sarbanes & Oxley Compliance Tool. New SAP releases come with some add-on preloaded, too. PI (Plug-In) is a good example. It's used to exchange data with other applications such as BW and APO.

A CRT (Conflict Resolution Transport) is used when you have installed an Add-on and Support Packages that conflict with each other.

Who decides about what patch should be applied and when? That's a good question. The answer is: You, the customer.