Float Ownership & CPM Schedules – 2015
Norman F. Jacobs, Jr.,
What does your specification say about CPM Schedules and float ownership?
Today we live in a new era of construction cooperation. When it comes to project float, sharing it between the contractor and owner is in, while exclusive float ownership by either party is out. Although “float” is generally understood in the construction industry as extra time or leeway for completing a project schedule, its use remains controversial. At stake in the float debate are hundreds of millions of dollars lost or won in timely completions or delays. Some say float calculations are fraught with deceptions.
What is the variability of float? The calculation process to determine float is arithmetically precise, but the data used in the calculation is a collection of estimates, guesses, simplifications and assumptions. Once created, float is ephemeral; the effluxion of time will of itself destroy float [there is no float on completed activities]. Similarly, float cannot be bought, sold, stored or transferred, it only exists as a result of an arithmetic calculation, on some future activities in a schedule and any changes that occur during the execution of the project can have dramatic effects on the overall schedule and all of its embedded float values.
Sharing float is rarely clear in case law regarding contracts, and it harms contractors in significant ways. By depriving contractors of use and control of the schedule they create and execute in carrying out the work, float-sharing cuts the connection between risk, responsibility and control. If timely completion resides in the contractor’s domain, control of time belongs there, too.
Float can lead to other problems. Float, for example, has been described as the period between the earliest possible start time for an activity not on the critical path and the latest time the activity can possibly finish, minus the actual number of days to do the work. Be very sure to know the terms such as total float, free float, activity float and project float that are confusing because they carry different meanings.
The Project Manager must know the consequences of consuming float. Float unquestionably provides a contingency within the schedule that can be used to offset problems and delays, but any reduction in float increases the risk of project overrunning. As more paths through a schedule approach criticality there is an increased likelihood that a delay on any one of the near critical paths will cause the project to finish late.
Gaming and manipulating float is a common worry of some construction people. Any gamesmanship up front, if even possible, will likely yield unintended consequences to the project CPM Schedule.
The benefit and ability to manage float should always follow the responsibility of managing and meeting the schedule. Float is one of the most important and least understood aspects of project management.
Check specifications as to the use of any CPM Schedule 3m’s; such as manage, massage or manipulate.