Claims Critical Path

David’s reference is a very good one; it defines the true meaning of Critical Path.



It does not rule out the fact that resource availability might be critical. It wisely avoid to mention float as many of today software show float for resource critical tasks, this in conflict with the true meaning of float.



Just schedule a 2 activities network, not tied one to each other by precedence logic but sharing a limited resource.



For example:



A Comb Hair 5 minutes

B Tie Shoes 5 minutes

Both activities sharing your hands as a common resource.



Most software under resource leveling will schedule A and B at different time, the first one depending on your priorities selection. This is ok up to this point, but the problem is most will show float of 5 minutes on the first activity while a delay in this activity will delay the completion of your schedule.



Just imagine that you as a Project Manager look at the available float as per your CPM schedule and start paying attention to those shown as critical and even start moving resources from those showing some float as to keep under control those showing no float. Because most software under resource constrained schedule will show the wrong float for resource critical activities you most probably will end up moving resources precisely from the wrong activities. You either will discover too late it was wrong or start doubting about the CPM float display. Well better start doubting about the CPM float display and either buy a glass ball or a software capable of showing resource critical float.



Seems like judges have more common sense than most software vendors.

James



I always find it useful to have some legal authority to rely on, especially if you are going to cite it in an expert report. You might like to take a look at Mirant Asia-Pacific Construction (Hong Kong) Ltd v Ove Arup and Partners International Ltd & Anor [2007] EWHC 918 (TCC) (20 April 2007) (you can read the full judgment at http://www.bailii.org/ew/cases/EWHC/TCC/2007/918.html#para119).



...........

119. The term "critical path" was used frequently in the course of the hearings by programming experts and non-experts alike. I was concerned to have a precise definition of what it and associated terms meant and after the hearing the parties provided me with an agreed reading list.



120. What is known as the Critical Path Method is frequently used by the construction industry both in the United States, the United Kingdom and elsewhere in planning construction projects and in analysing the causes of delay.



121. The critical path can be defined as "the sequence of activities through a project network from start to finish, the sum of whose durations determines the overall Project duration". See BS.6079 – 2.2000 Part 2, 2.41.



122. In the helpful work, Delay and Disruption Contracts by Keith Pickavance (LLP 2005), the author makes the point that the Critical Path Method requires detailed and sophisticated analysis and that in complex projects it is unlikely that a critical path can be identified inductively, i.e. by assertion. "It can only reliably be deduced from the mathematical sum of the durations on the contractor’s programme to be completed in sequence before the completion date can be achieved." This is an important cautionary word in this case where a number of witnesses were convinced, without the benefit of any such analysis, that they knew where the critical path lay.



123. It is important to have in mind that there may be more than one critical path. The Society of Construction Law Delay and Disruption Protocol (page 54) confirms:



"There may be more than one critical path depending on workflow logic of delay to the progress of any activity in the critical path which, without acceleration or resequencing, may cause the overall Project to be extended."[1]

...........



David

Definitively float and critical path terms shall be banned from claim analysis as long as people insist in using unrealistic old CPM theory incapable of modeling real life, incapable of modeling what happened.



In real life you might have several activities not interconnected to each other that might delay the project duration under resource constraints.



Outdated CPM software do not show resource critical path and even show available float for some activities that if delayed will not release some resources therefore delaying the start of other activities that might be critical.



Probably we need institutions that stand to the true meaning of cause and effect instead of being complacent of the interest of incapable software vendors.



Cordially,

Rafael Davila

To quote the First Gospel of Planning; "Program Evaluation Review Technique and Critical Path Method" by David Stires and Maurice Murphy of Booz- Allen & Hamilton, January 1963.

[This company developed PERT & CPM with the US Navy for the Polaris submarine in the late 1950’s] ~

"Critical Path - The sequence of interconnected events and activities extending from the beginning of the network to the end of the network which will require the greatest time to accomplish. Any lateness in any activity on the critical path will result in equivalent lateness at the end event. It is the path that consumes the least amount of slack." ["Float" in English.!]



Nobody can argue that is not the definitive version.

Dear James,



I find that this site is useful:



pmbook.ce.cmu.edu/10_Fundamental_Scheduling_Procedures.html - 118k - Cached





Hope that you find good information to assist you.



With kind regards,



Samer

Take a copy of your as built and work back from the final activity, removing actual dates and confirming / correcting the logic to ensure it also reflects what actually happened on site.



Each logical link you look at, make sure you understand (and note) why it’s there and of that type.



You will probably find you will need to insert new (delay) activities into the critical path in order to keep the dates correct eg if the final task B was preceded by A using an FS(0) link, but on your as-built, there was a 1 week gap between A finishing and B starting, insert a 1 week delay event between them, and find out what it represents. If you can’t find any information on why the delay occured, call it something generic like ’Contractor Delay’





Once you’ve done this, you’ll have the as-built critical path. This, combined with the notes you’ve taken along the way should be all you need to do the narrative.



If activity durations or sequences differ greatly from the baseline forecast, it is probably worth finding out why, and including this in your narrative.



For any delay events you feel are claimable, gather as much documentary evidence as possible to support the narrative, and make sure you’ve read, understood & complied with the relevent contract clauses.



HTH



Gary

Wasn’t it explained in the schedule (if any exist)?