Yapp the project calculator, Keep track of what to do and who's doing it. Rule based planning allows you to get some real help and not only a controlled drawing environment. Export and import to Excel Yapp the project calculator, Keep track of what to do and who's doing it. Rule based planning allows you to get some real help not only a controlled drawing environment. Most other project planning tools are ok drawing environments but they fail in coordinating available resources and their use. They do not give you any or only modest support in rule based planning. This project planning tool gives you up to date warnings on common rule violations like resource overuse, deadline breach, and dependency violations, information that is crucial to you in order to build a realistic and working project plan. Export and import to Excel