How many sub projects is too many sub projects and are there limitations to how many projects that can be usedIssue When creating Sub Projects, there are a few questions that often come up such as "is there a limitation to how many Sub Projects that may be used?" or "Is there a limitation for number of Projects?" While there are a few exacts here, many of these numbers and exact limitations are subjective to the data within those tasks. ResolutionOverall, a few guidelines and limitations can be given: Overall Project family should never exceed 34MB (That means if you navigate to the Top Task/Top Project and right-click the grey header, select 'Export to XML', download the XML, and inspect the size of this XML. If it exceeds 34MB, there will be many issues. One of those may be that the Project does NOT load in Planning Console.How many Sub Projects are too many? A: There have not been any limitations for this found! We have tested over 100 Sub Projects with 7 Project Tasks each and saw things running more-or-less smoothly, but this all does depend on the data within those Sub Projects and what actions are being made For example, if the action you are making is opening Planning Console, then 100 Sub-Projects with 7 Project Tasks won't have a huge effect. If however, those Sub Projects have 30+ tasks each (totaling over 3000 tasks), then loading as well as any basic actions such as updating states, updating dates, etc, will have a huge delay) How many Projects is too many? A: A soft limit/guidelines for this is 1200 Project Tasks. We have found, that once more than 1200 Project Tasks exist in a Project, slowness starts to creep in, especially in Planning Console *Why there are limits: In short, Planned Task and PPM run on a few base mechanisms such as 'Recalculate'. Whenever a Project or Project task is updated, the 'Recalculate' Business rule triggers. This then goes queries and updates through each project task. The more there are (and the more relationships), the longer this takes to complete. Overall, if your Project Tasks exceed 1200, there will be more and more performance issues as those numbers increase.