In the tutorial scenarios there is only one way to perform each task (in project management this is
called a mode). In the advanced scenarios some tasks can be performed in more than one mode, for ex- ample a task can be done in-house or by a subcontractor and the user must select one of the two modes for this task. Mode selection is an important decision in project management as the mode defines the type of resources required to perform the task, the required quantity of each resource type, and the expected dura- tion of the task. For example task A (task 1) is a single mode task (see Figure 3).