http://www.conceptdraw.com/products/project-management-software
I would advise you go check a powerful desktop ConceptDraw PROJECT app and a web-based ConceptDraw PLAN tool. Setting predecessor and successor dependencies between tasks will not let you start a new one before finishing a previous one.The Complete Value is great for updating your current status. But please note the visualization is calendar based though.
Switching to Mac from PC now and trying to find a PM tool look-alike to MS Project which opens MS files. Mac forums discussions.apple.com recommend few: Merlin, Omni and Conceptdraw Project for $199 and it’s just great as they let you to trial it for 21day. I run same license on my macbook at work and PC at home.