Using SharePoint Designer 2013 to Create and Modify Project Workflows
Hello everyone!
My name is Sam Chung, and I am a Program Manager for SharePoint Designer. I’d like to introduce everyone to a great new feature we’ve introduced in SharePoint Designer 2013. For those of you who work with Project Server Workflows, you’ll be aware that ALL previous versions of Project Server workflows were only created using Visual Studio. Well, this is no longer the case in Office 2013. The SharePoint Designer team has partnered up with the Project team to create a great seamless integration of the two products.
Now, luckily for me, our partner team Project has already gone ahead and created a blog posting on how you can use SPD for exactly this, and as such, all I have to do is link to their blog. 
So without further ado, please point your browsers to the below link and read all about this great new feature.
Thanks,
Sam