Kelly,
The short answer is that MS Project is and EEF. Below is an answer to your question that I pulled from Aileen Ellis website. Hope this helps.
Mark
aileenellis.com/pmp-certification-exam-a...onmental-factorseef/
Lets take another example: is MS Project an enterprise environmental factor or an organizational process asset?
Aileen’s Answer for the CAPM Certification Exam and the PMP Certification Exam:
The software tool- MS Project is an environmental asset. The data we use to populate MS Project (we may call this project data or project information) and the schedule model and the schedule presentation (the schedule) created from this data are all organizational process assets.