Andrew

Hi Angela

Thank you for your question. Lag is a value entered by the Project Manager that creates a gap between Predecessor and Successor measured in working days. Lag will remain the same regardless of changes to the predecessor.

Float (or Slack) is the name for the gap between Predecessor and Successor is which is often created as a result of the Successor having a constraint set later than the immediate finish of it's Predecessor. This gap is flexible so if the Predecessor is delayed the gap is reduced.

I hope this helps - let us know if you have any further questions.

Kind regards,
Andrew