How many workdays occur from the start of the Product Testing to the Product Available...

The number of workdays between two milestones, such as Product Testing and Product Available, is calculated by considering the activity durations, dependencies, and any calendar constraints (PSP Study Guide, Subchapter 2.2.3, "Durations"). If the activities are continuous and there are no interruptions such as holidays, the total duration would sum to 100 days based on the provided schedule.