Delay analysis with total float

Hi, Mike. Thanks for getting back to me so promptly!



Unfortunately, it’s early morning here in Boston, and I’m rushing out to teach a scheduling class, so won’t have time to respond fully until Monday. (After all, there is a WI vs. England Test Match to focus on this weekend! Not to mention S. Africa vs Aus.)



Here are two articles at ProjectsatWork.com that might help. The first is written by Bill Duncan (’though he was kind enough to list me as co-author despite the fact that it is almost entirely his writing). The second is by me.



One thing: ProjectsatWork.com requires registration to read articles; but it’s free.



http://www.projectsatwork.com/departments/methods-means/



The Duncan article was re-published here on Jan 15th of this year.



The other article is from December 7th, 2006. Discussion of DRAG starts about halfway down the page.



http://www.projectsatwork.com/content/articles/234282.cfm



BTW, in terms of your comment:

"Disruption looks at any change in work sequence whether critical or not - you got it right in your 3rd paragraph."



Thank you -- the disruption issue makes perfect sense. I still wonder, though, if DRAG is not the way to address it, as described later on in my third paragraph:



"...I’d have thought that the way to analyze such a situation would be to isolate the deliverable/milestones ancestral paths, make it a sink activity and conduct DRAG gap analysis on that subset of the network."



Here’s to Windies winning the toss in Trinidad!



Fraternally in PM,



Steve D.

Hi Stephen



I need to understand some of your acronyms.



I assume ABCP means As Built Critical Path but I have no idea what DRAG means.



To begin with there is a difference between delay analysis and disruption of the sequence of works.



Delay concentrates primarily on the delay to the critical path.



Disruption looks at any change in work sequence whether critical or not - you got it right in your 3rd paragraph.



Change in float is significant in both situations.



In Delay analysis an event may use up all float on an imapcted activity and thus change the critical path and float on other activities.



This is why it is essential to imapct events in strict chronological order to represent - as near as possible the effect of the chain of events as and when they happened.



In disruption every event has to be considered whether it changed the critical path or not.



Best regards



Mike Testro

An honest question for all, as I really don’t know the answer, and there may be a very good one:



1. Why would analysis of total float be significant for EOT, or even for ABCP analysis? Since float is on non-CP activities, while DRAG is a quantitative measure of CP activities (also resource acquisitions and date-based constraints) that delay completion, shouldn’t DRAG be the preferred analysis for exactly this purpose?



2. Wouldn’t a gap analysis between activities’ DRAG on the baseline schedule and ABCP DRAG be a clearcut process for determining delay causes and EOT?



I guess I can see where float analysis might be significant if a deliverable/milestone off the CP (i.e., one that has float in terms of the entire baseline plan) is delayed and results in delay costs, even though it remains off the CP. But even then, I’d have thought that the way to analyze such a situation would be to isolate the deliverable/milestones ancestral paths, make it a sink activity and conduct DRAG gap analysis on that subset of the network.



Just looking to understand better.



Fraternally in PM,



Steve D.

Hi R Catalan



Your suggestion that you first fiddle the programme and then trick the Client/Engineer into awarding an EOT is a dangerous practice.



Not only is it immoral but in some Countries it is criminal fraud.



If ther is a lot of float then it is there for the benefit of the project on a first come first served basis so my advice is.



Plug in all the contractors delays and use up as much of the float as possible.



Then enter all the clients delays and see what happens.



You may be challenged if you do not enter the events - both contractor and client - in strict chronological order.



Another thought!



Is the float a contingency buffer at the end of the programme or is there a critical path somewhere in the system?



Another possibility is that there are end links missing which will give a wrong impression on available float.



In which case they can be added - this is rectification of the programme - not manipulation and is valid.



Best regards



Mike Testro

Mark,



There’s a way.



If you have made some changes on your plan in order to catch up with the time for completion and you can influence the Client/Engineer that it’s time to revise the approved baseline program since scheduling parameters does not reflect anymore the actual progress on site, then you can submit a revised plan incorporating the delays incurred.



Your revised program shall be substantiated with supporting documents that leads to the delays. Avoid using any reference to the approved baseline on your determinations so you don’t open up issues related to it. Get your revised program approved first then build your EOT claim by using it.



R. Catalan

Mark,



Use impacted as planned. It is very simple and economical. It maybe acceptable for imterim award of EOT, meaning, to avoid liquidated damages, LD.



Cheers,

Happy Planning and Scheduling

Dear Friend,



Since it seems that you are the Contractor and the Program in most cases prepared by the Contractor, we need to ask two questions:



1. Is this Program of Work realistic and representing the progress at site?



2. Is it approved by the Engineer?



Best Regards,



Samer

Will be difficult, you may want to see the status of the schedule when the delay happended. The floats may have been used up.



Cheers..