Widgetco is about to introduce a new product (product 3). One unit of
product 3 is produced by assembling 1 unit of product 1 and 1 unit of
product 2. Before production begins on either product 1 or product 2,
raw materials must be purchased and workers must be trained. Before
products 1 and 2 can be assembled into product 3, the finished product
2 must be inspected. A list of activities and their predecessors and
of the duration of each activity is given below.