"Calculating and Using Float" by Patrick Weaver

Abstract:

Schedule Float is the creation of the Critical Path Method (CPM) of scheduling. Before 1957 ‘float’ only had one meaning now it has several. The origins of scheduling and consequently float is discussed in two papers: 

• A Brief History of Scheduling
• The Origins of Modern Project Management

The issues of creating float within networks and the options for manipulating float (legitimately or otherwise) through the structure of the schedule is discussed in the papers:

• Float - Is It Real?
• The Cost of Time - or who's duration is it anyway?
• Schedule Calculations

The purpose of this paper is to support the concepts discussed in these earlier papers by analysing the various types of float that have been defined in the last 50 years and considering how they may be used in modern scheduling practice.