looking for a recommendation

A few people need to collaborate on a project. I would like to know if someone can recommend a few different plugins for this.

A project sample might be that they take an application, and each member of the team has a task to do with that application ( person submitting a request to join for example). One task would be a background check, another might be a call to check credentials etc. They do their task, and sign off, and the next person takes up their task. Each member would have to be able to post their results and others would see it.

If not a plugin, then perhaps a small forum where only they as members would be able to login… suggestions?