I would say "sure", so long as Planisware is offering a web interface with HTTP protocol. That is WebInspect's bread-and-butter.
From Wikipedia, "Planisware 5 has a three-tier architecture: a browser on the client side, an application server, and a database. On the client side, Planisware supports any mainstream browser on MS Windows, Linux/UNIX, and Mac platforms, and runs with either a Sun Java plug-in or an Ajax applet. The Planisware application server combines with a classic Web server (IIS and Apache). The database can be either Oracle or SQL Server."
That sounds like pretty much everything we scan with WebInspect. Similar to dealing with large CRM systems, I suspect your complications will come in determining the optimal scan configuration for the target to efficiently crawl it and also not cause undo extraneous records or events. There may or may not be custom state-keeping variables, dynamically built web pages (and dynamic names), redundant pages, or specially required work flows. All of these are standard problems and nothing special.
If you have difficulty with the Crawl, provide some scan export data to Fortify Support and ask for their assistance in reviewing the Request traffic. (https://support.fortify.com)
-- Habeas Data
Micro Focus Fortify Customers-Only Forums – https://community.softwaregrp.com/t5/Fortify/ct-p/fortify