When does the descriptive programming preferred?

1.When we start the automation even before the application comes for automation and only some document related to the application available.
2.when object repository size exceeds its maximum size .
3.when there are dynamic objects in the application.
4.execution is faster with descriptive programming .
5.when object repository is read only and we can't add any more objects..


We can write the desc pgmg script on a particular object without adding it to the object repository file by giving the physical description of the object directly in place of the logical name.