I need to make change in one single step of process model in Wm 9.6 - that is include a new correlation service to receive step .
Do I need to include IS in implementation for all steps and build and upload the entire process for this ?
Also I have a scenario to delete one step in process model - here also do I need to do the same ->include IS for all steps and build and upload the entire process for this .
hopefully your process models are implemented to call an existing service on IS (which additionally should reside in a different package than the generated process services for the steps).
In this case you can simply delete the generated services and triggers from the process package and regenerate them using build&upload.
For your first question:
Is the modification affecting the step in the model or only the internal business logic of the step?
If only the internal logic is affected it is not neccessary to build& upload the process.
I think that adding a correlation service requires a build&upload to get the process fragment file in the package regenerated as well as the neccessary objects updated in the process runtime database.
From your previous posts I see that you are trying to migrate from 6.5 to 9.6.
Unfortunately there is no upgrade path for this as a direct migration.
It should be done in 2 steps:
6.5 → 8.2 → 9.6 (if direct migration from 6.5 to 8.2 is possible)
If direct migration from 6.5 to 8.2 is not possible it will become a 3 step migration:
6.5 → 7.1 → 9.5 → 9.6 (or newer)