Calculating the Schedule,
Elapsed Time ≈ 2 Hours
CALCULATING A SCHEDULE
• The forward pass will calculate the early dates for activities starting at the beginning of the schedule and working through to the end of the schedule. These dates are the earliest dates an activity can start and finish based on the logic, durations and constraints input to the schedule. All predecessors must be completed for the early dates. These dates are usually optimistic as they assume everything will go according to plan.
• The backward pass will calculate the late dates for activities starting at the end of the schedule and working to the beginning of the schedule. These dates will be the latest an activity can start and finish based on the logic and durations input to the schedule without affecting the overall end date of the project.
• The critical path is the longest logic path through a project network. There can be more than one critical path through a project.
• The total float is the amount of time an activity can slip without affecting the overall project completion date. The float is calculated as the difference between the late and early finish dates of an activity. Activities on the critical path typically have “0” float but can have negative or positive float. The early and late finish dates for an activity that has “0” float are the same. For an activity with negative float the late finish date is earlier than the early finish date. The network logic and durations have determined than an activity can not finish any earlier than a certain date but the activity must finish earlier than that date or will affect the overall end date of the project.
• The free float is the amount of time an activity can slip without affecting the start or completion dates of a succeeding activity. The total and free float values for an activity can be and most likely will be...