Best Practice 7: Ensuring Reasonable Total Float

Key Questions

1. Are the total float values that the scheduling software calculates reasonable and do they accurately reflect true schedule flexibility?

2. Are excessive values of total float being driven by activities that are missing logic?

3. Is total float monitored? Does management have a plan to mitigate negative total float?

4. Does management rely on free float to level resources or reassign resources to assist critical activities?

Key Documentation

The program team can use a list of activities sorted by their total float values to determine whether the total float values correctly reflect flexibility in the program schedule.

Likely Effects If Criteria Are Not Fully Met

1. If the schedule is missing activities or dependencies or if it links activities incorrectly, float estimates will not be accurate. Incorrect float estimates may result in an invalid critical path and an inaccurate assessment of program completion dates. In addition, inaccurate values of total float falsely depict true program status, which could lead to decisions that may jeopardize the program. For example, if activities are not linked correctly to successors, total float will be greater than it should be.

2. Without accurate values of total float, it cannot be used to identify activities that could be permitted to slip and thus release and reallocate resources to activities that require more resources to be completed on time.

3. Negative float indicates that not enough time has been scheduled for the activity and is usually caused by activities taking longer or starting later than planned, making target dates infeasible. The program may have to take some corrective action or the negative float may act as a threat to the program end date.

4. Too little float built into the schedule may indicate insufficient time to recover from delay without the program’s completion date slipping.