If you have documentation relevant to a process step, you should attach it to an activity
All third party documents need to be stored in a location or document management solution that enables access via a URL. There are some great cloud storage solutions like Box.com, Microsoft OneDrive, GoogleDrive or Dropbox. All of these have business specific versions and some have solutions up to enterprise level. You may already have an implementation of a solution like SharePoint, M-files, Filenet or Documentum. There are literally dozens of solutions. As long as you can access the document or file you want via a URL, you can attach it to an activity.
If you have process content in other applications that you want to bring into Elements format, the fastest and easiest route is usually to manually map it out. It’s quick to map and you can transform the content into the Elements simple notation and hierarchical diagrams as you go.
Importing maps from other BPA tools
There are some third party apps like BPM-X that will take content from a number of modeling tools and convert it to a XML. Some apps like TIBCO Nimbus export their process content into an XML format.
Internally, we have an import routine that will take various XML formats and will build a full Elements map using our open API.