I’m in an Organizational Social-Psychology PhD program. So I will give you my 2 cents.
You don’t actually need to have a PhD to do research but I am assuming that assessing the efficacy of a whole program is maybe too big for a research study. Maybe you can if have the whole set of theories soundly validated and validity for your measures. But that is a big maybe…
Do you already have this program running? Do you wish to measure it only or do you want to publish? Coming from the Organizational Development industry, if you wish to measure just for internal purposes, I would say a qualitative interview with your clients would be enough. If you wish to publish it, considering you are able to do everything right, you will need to get an IRB approval before running anything.
Honestly, I think this is a way to big feet to complete without any kind of support or coming fresh right out of a masters program.