High Float

The DCMA states that no more than 5% of incomplete activities should have a float of 44 days or more.

Float, or slack depending on where you are from, (MS Project calls it Slack) is the amount of time that a task or activity can be delayed, before it starts to impact the programme.

There are two types of slack – Free and Total slack

• Free slack is the time a task can be delayed before it impacts the start of its successor tasks
• Total slack is the time a task can be delayed before it affects the critical path and hence the finish date.

DCMA identifies high float (slack) as being 44 days or more (2 working months).  At first glance one might assume that this is a good thing.  However, in a correctly scheduled programme its far more likely to be an indicator of missing predecessors/successors and consequent gaps in the logic network.

As with most things, there may be a perfectly valid reason why a task has a high float, and this is why there is some latitude displayed in the allowance.