What is the recommended limit of subprojects under a master project before the users will start impacting response times? Are there other considerations?
Don't think there is any.
However, check the below -
RE: Clarity to MSP thresholds
Our current project inventory has seven hierarchical levels. At the upper levels (2-3) there are between 15-45 subprojects. As you move down the hierarchy the number of projects drops down to between 2-5 subprojects. At this point, the only performance issue is using MSP as noted by NJ. The only Clarity UI issue we have run into is filtering on hierarchy (trying to locate a subproject with its associated hierarchy).
This is what the project management guide v13.3 says
Add Subprojects to Master Projects
Use the following procedure to add an existing subproject to a master project. You can add an unlimited number of subprojects to a master project.
Bearing in mind that it is suggested that there should not be more than 100 subobjects for a parent object.
Also have a faint recollection of Josh or Suman posting a specific number.
Lot of subprojects under a Master Project, WBS Gantt view of the Master Project including the subprojects might error out depending on the number of subprojects.
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