As Built Critical Path

On the assumption that this is a serious discussion, I thought you might appreciate knowing that in Egger, The court does not refer to it as a time impact analysis nor does it describe any methodology from which it could be infered that what I did was a time impact analysis.



In fact the court did not look at the analysis or my report. That is clear from the judgement.



In the case on costs that is referred to the court takes the unusual line in relation to the claimants case that my report did not follow the pleadings or the facts. Hitherto it has been held that an expert is not supposed to follow its clients pleadings but to advise the court and which of competing facts is adopted seem to be a bit of a lottery.



Incidentally, does anyone see any pattern in Egger and Great Eastern Hotel?

Uri and all…



As you mention Keith Pickavance, you may be aware that he did recently enter the fray on this subject at http://www.planningplanet.com/forum/forum_post.asp?fid=1&Cat=7&Top=8636. However, one must bear in mind that he is an ‘architect with a legal education’.



With KP being a vocal member of the drafting committee of the Protocol it is understandable that the Protocol and his book express similar opinions about Time Impact Analysis. As KP will know, in this instance, I could not have articulated the sentiments he makes about Time Impact Analysis better even if I had written them myself.



For TIA to be effective reliable base line programme is required and the impact analysis is only as good as the data put in and be supported by the pleadings or the evidence otherwise, as you suggest Uri, such inadequacies can generated a great deal of out of court time and expense and be a red herring of little value.



The criticisms of KP’s application of TIA continues in Skanska Construction UK Ltd. v Egger (Barony) Ltd. [2005] EWHC (http://www.bailii.org/ew/cases/EWHC/TCC/2005/284.htm), paragraphs 166 and 167.



Regards



David

David,



The Protocol on the published version of October 2002 clearly recommends the TIA to be used "whereever the circumstances permit" (section 3.2.11 page 44), and also "TIA is the most thorough method of analysis..." (section 4.16 page 48).



Keith Pickavance in his book (2000 edition) also seems to prefer TIA - "in the author’s view this is the only way in which the true effect of an event can be analysed..." (section 12.160 page 447).



The problem with TIA is that it is more expensive and more time consuming. However, when you take shortcuts, you might end up in the wrong destination...

Uri and all…



As I said in my message, I do think we need some decent definitions, the problem being one of interpretation and nuance.

I hope I didn’t give the wrong impression but in essence I agree with what you are saying; ‘Time Slice Analysis’ and ‘Windows Analysis’ are the same thing and ‘Time Impact Analysis’ and ‘Snap-Shot Analysis’. I’d prefer to drop the ‘Windows’ descriptor (it’s close association with Miscrosoft often leads to confusion) and similarly I’d prefer ‘Time Impact’ to the less formal ‘Snap-Shot’.

The techniques are broadly similar and, as you say TIA leads to a more refined analysis as it deals with individual events whereas TSA potentially deals with whatever number of events happen within the selected time period.



With regard to the Balfour Beatty case you can read the judgement here http://www.adjudication.co.uk/cases/bblambeth.htm. The methods were not listed in order of preference as far as I can tell, they were preceded by:



Before looking at the “final as-built programmes” exhibited by BB, Lambeth would make passing reference to the delay analysis methods most widely recognised and used: .



It is interesting that later in the Judgement the methods cited by the SCL Protocol are listed in order of preference:



1. Time Impact Analysis

2. Windows Analysis

3. Collapsed As-built Analysis

4. Impacted Plan Analysis



But this was taken from the November 2001, Consultation Version. Those familiar with the Protocol will know that in the final published version the types of analysis ‘recommended’ were:



1. As-planned v as-built

2. Impacted as-planned

3. Collapsed as-built

4. Time impact analysis



You will see that Windows Analysis has been replaced by As-planned v As-built. It would be useful to have some input from anyone who was intimately involved in the formulation of the Protocol. Does this mean that Time Slice/Windows Analyses is not a recommended method and has this come about as a result of deliberations between draft and final publication.



Regards



David

David,



TERMINOLOGY QUESTION.



I was confused by your last post (01 March). Is ’Time Slices’ analysis is the same as ’Windows Analysis’ or is it the same as ’Snap Shot’ or ’Time Impact’ analyses? To me the word ’Slice’ is more like a window than a point in time, as the term ’snap-shot’ suggests.



Correct me if I’m wrong, I think the difference between ’windows’ and ’snap shots’ is the RESOLUTION of the analysis - i.e. ’snap shots’ yield to more refined analysis, wheras ’windows’ is a more coarse one.



In this Balfour Beaty case that you are refering to, are the technique listed in an order of preference?



Thanx

The Great Eastern Hotel -v- John Laing Construction case raised some topical issues for planners. As has been correctly pointed out below, I was one of the delay analysis experts involved with the case. Sigfredo, Gerry and David ask some questions about the approach taken in the delay analysis, which I will answer.



The main question relates to the method of delay analysis used and the Judge’s statements in paragraphs 67 and 184.



In paragraph 67 the Judge wrote “Mr France used an impacted as planned programme analysis by which the project is analysed on a monthly basis to measure the impact of events as the project proceeded.” This is not strictly correct. For my main delay analysis work, I used what David helpfully describes below as the Windows Analysis. That is, for each month (or “window”) of the project, at dates co-inciding with the monthly progress reports, I looked at the progress position achieved and inputted that progress into the master programme to assess the delay that had occurred and what activities were on the changing critical path. I then investigated the reasons for that delay in that window, before moving on to the next monthly reporting period window.



In this way, I divided the project period into “windows”. The benefit of this method is that I put myself into the position of the people involved in the project at the time, looking at the situation at the time, with issues such as progress achieved, the design status and variations that had been instructed.



In paragraph 67 the Judge correctly describes the method used for the main part of the delay analysis by the defendant’s delay expert. “Mr Calekta for the main part proceeding retrospectively from an as built programme to determine the critical path and respective periods of delay and causes.”



What I have described above relates to the main part of the delay analysis, that is, what was the main critical path through the project, what were the delays to that critical path and what caused those delays.



Paragraph 184 is discussing a different aspect of the case. This concerned concurrent delays. The defendants argued that in addition to the main delays to the critical path through the project, there were other delays caused to concurrent activities, mainly caused by late design release. For this part of the case, Mr Caletka used the impacted as-planned method, in which he stated what the impact of that late design would have had on the original programme. As you will have read, the Judge didn’t like that approach because it didn’t take account of the actual events that had occurred on site.



Sigfedo asks if the Judge had a preference for an impacted as-planned programme than a retrospective as-built programme. I can see why Sigredo asks that question due to the wording in paragraph 67. No, I don’t believe that is the case as paragraph 184 makes clear, for the Judge didn’t seem to like the impacted as-planned method. He did seem to prefer a windows analysis over the retrospective as-built method.



I hope this clarifies the situation.



Gary France

Gerry and all...



This may be getting away from the original thread but I think we need some decent definitions here or we are all going to be confused with what is going on and what the Courts seem to think is acceptable or not.



I don’t think what is described at paragraph 67 is ‘Time Impact Analysis’ (although it could be a time impact analysis).



IMVHO ‘Time Impact Analysis’ is event orientated, the network is updated with progress just prior to, or at, the time an event occurs. This brings the programme up to date as far as current progress goes. Then the discrete event is simulated and it can be determined the effect of that particular event. This is described in the protocol (amongst other places).



I believe what is being described at paragraph 67, and Gary will have to confirm this, is ‘Timeslice Analysis’ (or ‘Windows Analysis’). This is time orientated inasmuch as the project is divided into timeslices (typically monthly) and the programme updated to reflect the current position at the beginning of the period. Then all the events that happen during the period are simulated. The effect on completion is a result of all the events simulated during the period. Not quite as clear cut as TIA (discussion on that point is for another thread I think) but it is useful for projects where there are masses of smaller type events (typically late information and instructions/variations type delays). Also it is generally less time consuming for a full TIA.



Balfour Beatty Construction Limited -v- The Mayor And Burgesses Of The London Borough Of Lambeth [2002] EWHC 597 (TCC) is a case often cited that gives some clues about what was considered to be the most widely recognised and used delay analysis methods:



(I) Time Impact Analysis (or “time slice” of “snapshot” analysis). This method is used to map out the impacts of particular delays at the point in time at which they occur permitting the discrete effects of individual events to be determined.



(II) Window analysis. For this method the programme is divided into consecutive time “windows” where the delay occurring in each window is analysed and attributed to the events occurring in that window.



(III) Collapsed as-built. This method is used so as to permit the effect of events to be “subtracted” from the as-built programme to determine what would have occurred but for those events.



(IV) Impacted plan where the original programme is taken as the basis of the delay calculation, and delay defaults are added into the programme to determine when the work should have finished as a result of those delays.

(V) Global assessment. This is not a proper or acceptable method to analyse delay.



I was a little confused by paragraph 184. It seems to give the impression that impacted as planned analysis was being carried out by Tony whereas I thought he was using an as built programme? Have I got the wrong end of the stick?



Regards



David

Hi Gerry,



thanks for the link, I’ve read some parts of it and I found it very interesting not to mention one of the more active PPers stood as an expert witness.



I just want to point out one portion of the court ruling for now. It seems to me the judge has a preference for an impacted as planned programme than a retrospective as built programme. I hope Mr. Gary France can enlighten us on this.



cheers,



Sigfred

Hi Gerry do you have a link to this.

Hi David,



Sorry for the delay in replying to your question about fairness, as it took a bit of reflection upon my career. But the answer I have come to is yes I believe I am, in most instances, although there has been a few times, I did not practice what I preach, but it was due to circumstances, where there no transparency existed. Helping contractors/subies, avoids problems in the future. If you explain things to them in the right way, it tends to obviate the same problems re-occuring. At present I am working on a NEC (New Engineering Contract) project, and find it most to my liking, as it is a give and take situation, and transparancy is the rule, but you still don’t wash your dirty laundry in public. The rule is if you mess up admit it, but in the correct forum.



Hope this answers your qustion.



Regards,



Philip

David,



A most interesting link.



Thank you



Chris Oggham

Dear David,



Thanks a lot for your valuable link.





Cheers!!!





Daya

David,



Thanx for the info on the Keane Associates paper on this old perennial!! (and I don’t mean me) ;-)



Cheers,



Stuart



www.rosmartin.com

Planeteers may like to know a paper on this subject has just been published by Keane Associates (www.keane-associates.com) at http://www.geg13.dial.pipex.com/Site/Content%20Pages/Updates/PDFs/Client%20Update%20-%20JAN%202005.pdf.



Regards



David

Philip



The activity may have been critical at the time. The point is that retrospective delay analysis is alive and kicking. Whilst I agree that delays should be notified at the time (and they mostly are) the fact remains that for various reasons there is often the need to find the ABCP.



However whilst I agree that entitlement should be dealt with as the project progresses and that best practices should be in place, the fact is that throughout the World, this isn’t always the case.



In the ’aftermath’ of a project after say two years of arguing (it must be remembered that just because a contractor notifies of a delay during the project, it doesn’t necessarily mean it will be agreed by the employer) the contractor decides to formalise his claim by proceeding to arbitration or litigation. How would you work out which events really did delay the completion of the project?



As far as your question are claims worthwhile? That obviously depends on the cost benefit analysis - most commercial organisations would say that it is worth spending 2 years and $1m fighting/defending a $10m claim if it is shown that he has a strong case!



Out of curiosity, as a fair minded individual; if you know one of your contractors has an entitlement but has not recognised it for himself at your weekly meeting - do you help him to identify this entitlement?



David

Hi Ron and David,



If I may step in again, and try and save the horse not only before it bolted, and is flogged to death, but before it is minced for sausages, to try and prove an ABCP is near impossible unless you have a well documented history, and what this history will show you is reasons for the delays.



Something can only be critical before it is about to happen, or during the time it is happening, once it it completed how can it be critical? This is the reason you should report a delay prior to it happening, or during the time it is happening, not after the project is happening. Where I come from, and I believe this is international contractual law, you have to notify of a possible delay as soon as possible, or within a specified period. So what is the point of trying to find an ABCP in the aftermath. If you have warned the client/managing contractor/contractor of such an event you have a right to a claim, if not you have not done your job as a planner. In every weekly meeting I am involved with, that is about 7 of them, involving contractors, they are asked if there are any potential or possible claims or any outstanding financial issues, we believe in fairness, so if the answer is NO they revoke their rights to any such issues, it is their job to report any problems, and mine to forward these, To my client/managing contractor. Should this fairness not be there, and the the matter is not minuted, they have the right to arbitration/litigation. So as a planner your job is to make sure, no matter where you sit in the tree, that you either be pro-active and give warnings at the right time, or ask the right questions. As somebody dealing with or consulting/advising on claims, you should make sure your employer/client, has these measures in place.

As somebody who believes in fairness, I think, you should also assist the contractors/subcontractors to ensure that they gave the right measures in place should they have an entitlement (Claim), and this could be done by auditing them on a regular basis and assisting them in ensuring they know the procedures. This can save any project a major amount on litigation or claim fees, and ensure everybody stays in business, as we should unless our practices are poor. Take a look at the cost of claims, and let me know if they are worthwhile. We should be handling claims in progress, not months/years after the fact.



An instance, I have to mention, in the recent past, happened on a plant in Mozambique, where the managing contractor stepped out of the fray, and six months later announced a n aditional profit of lets say $m40 and this was roughly the money lost by all the contractors. Try making a claim in Mozambique. The Managers all pocketed big bonuses nevertheless.



Back to the ABCP, I still think it is BBB (if anybody wants the meaning, contact me privately), any decent planner should have ensured there is a good costing system in place, in parrallel with planning, and this wiil be a better way of finding where the problems lay, and help to ensure better estimating and planning for future projects.



So "BASTA" to the so-called ABCP BBB.



Regards and thanks to All,



Philip J

Ron

Whilst I understand what you are saying, doesn’t this method simply mean that every activity will eventually become critical by virtue of the fact that the as-built float is used up? In my piling example, the activity was not critical in its entirity but your method would not reveal that, or would it?



At the end of the day, is the only way of determining the path for an planner to apply experience and common sense by reviewing what was being done in as much detail as possible, ie completion of piling in zone A allowed foundations to commence... and so on?



DW

David,



You can approximate the remaining duration of an activity on any given date the same way engineers always have – you interpolate between known points. You know the original duration and actual start or the remaining duration at the data date and you know the actual finish. Use a linear regression to estimate the remaining duration at any point between those two points.



Luckily, all of the work is done for you if you use an Expected Finish constraint. It is as simple as that.



Ron Winter.

Hello everyone,

Well this has been a long but interesting discussion. I thought I might jump in. First of all the answer to the ’does an as-built cp exist?’ is a definite yes. For example, if we take two simple activities, say piling and foundations, and evidence shows that the piling finished 6 weeks before founds - are we saying that the completion of the piling 6 weeks earlier was critical to the completion of the founds? The answer may be no, and the piling did not need to be finished until 2 weeks before the end of foundations, so there existed 4 weeks of float. The start of piling to the start of founds, however, probably was critical.



I have often seen Gerry’s --xx-x---xx--x-xxxx-x example in real life and as planners we know how to do manual forward & backward passes, but in the disjointed as-built example the normal method of calculating cp does not apply, does it? So is it acceptable for the planner to use his own experience & common sense to work out the critical path?



And Ron I agree with what you said about critical activites being different on a daily basis, but how do you look back at a particular day/week/month and work out what was critical at that time in the absence of progress data?



Like others I prefer ’windows’ analysis, however the progress data does not always exist and the --xx-x----xx info may only be available in a simple diary format - what then?

Mudassar,



I’d like to congratulate you on your concise message on this thread. I like your ’progressive critical path’ terminology.



I notice you only became a member of PP a few days ago, and look fowrard to your views on the ’claims’ forums in the future.



Roger

I found this topic to be a most interesting discussion. Ronald Winter’s post of 9/12/04 6:37 was the ‘Eureka’ post that summarised it for me.



I’m making these comments from a delay claims analysis perspective.



I believe there is such a thing as an As Built Critical Path. Otherwise I would be out of my job and might have to give back last few years of salary.



We might not want to call it an As Built CP although we constantly refer to it in delay claims analysis. I have used the term ‘Progressive Critical Path’ in a number of reports I have worked on as it was based on the analysis of the logically linked status programmes issued by the Contractor. I’ll use the term Progressive CP for now; seems like a bread winner to me.



The Progressive CP basically shows which task is (I’ll come back to this) critical on any given day during the duration of the project and yes, it is subjective and depends on the skill, experience of the planning analyst, as built information and contemporary records available to and relied upon by the analyst.



Theoretically, if I have a crystal ball that allows me to see which task is critical on any given day, as far as I am concerned that is the task that needs to be progressed that day. If there is no progress on that task on that day it WILL delay the completion of the project by 1 day.



For a claims analyst, the Contractor’s programme (a CPM network) is the best starting point for such a crystal ball (or insight) into a project. It is a readily available source of the Contractor’s methodology for when and how he intends to complete the project. The monthly status programmes provide a snapshot of what the Contractor believes is critical on that status date (I am assuming that the Contract Administrator/ Superintendent is doing its job and reviewing the progress information entered and the forecast for the remainder of the works). We can use that information and using rudimentary mathematics and CPM logic in the programmes (labour intensive as it may be), to determine how individual tasks slipped (or lost float and became critical) during any two status programmes. This provides us with what IS critical on any given day between those two status dates. The smaller the interval between any two status programmes, the more reliable the resulting Progressive CP for that period.



Don’t worry that’s just the first attempt. We can and in most instances will definitely need to refine it through contemporary records (what was reasonably known by the Contractor on that date) and as built information (as suggested by Roger Gibson in his post of 5/12/04 12:14). That’s where the experience of the planning analyst is most important and the eventual Expert Evidence, if any. It also depends on the quality of the status programmes and the progress information entered in those programmes. It also depends on how much time and money is to be spent on the exercise.



Repeat this process on a succession of status programmes. After we have determined that set of tasks that was (or should we now say IS) critical for each day of the project’s life and combine it and overlay it on an As Built Schedule; you get a Progressive Critical Path (see Ronald Winter’s post of 9/12/04 6:37).



Using the bottom down approach, the fine tuning of the Progressive CP can be done to the umpteenth degree for the period/s during which the delay/s are claimed. If the delay lies on the As Built Critical Path, it was critical.



And yes, I agree with David Barry (post of 5/1/05 12:34) that the ‘connection between as-built critical path activities does not have to be physical, logical, resource driven or otherwise – the connection is simply that it was [of course looking back] critical at the time…”. The connection only tells us when an activity ceased to be critical and the critical path shifted to another task.



I can’t wait to check out the website/ software that Ronald Winter mentioned in his email of the 7/12/04 2:42. This could be an excellent tool for a Progressive CP analysis using the status programmes. At least it might take a lot of the manual calculations out of the analysis. Seems like I am using the CPM for similar purposes; except that I start from day 1 and move forward to the end of the project through successive statuses.



Ron, can I get a demo version 



MR

Uri, You’ve answered your own question; only by retrospective analysis.





Roger Gibson

Gerry,



Quote from you post: ’However, if the critical path did not switch between different chains of activities - then it could be accurate to describe it as the as-built-critical-path’.



Once the project is finished, how do you know if the CP switched during the project without retrospective analysis? it could have gone somewhere else, and later return to it’s original path. Would an ABCP be obtainable then?



Anyway, could you help me with the following question:



Assuming the ABCP does not exist, and that the Contract allows for ’actual delays to the date for PC’ only,how do you know which delay effected this actual date?

Gerry, Gary, David, Roger, Stuart and all,



This has been the longest and I think the most interesting thread we had on our claims forum sofar. It seems to me that now the subject is more or less exhausted.



I would love to see a paper summerising in a well structured way all the ideas and opinions brought forward under this thread.



Do you know of somebody, perhaps someone who needs a paper for the PEO, or a student that will take up such challenge?

Philip

Looking forward yes, Looking backwards no.

David

Hi David,



I started and learnt planning before computor aided planning existed, however, planning cannot be done without logic, whether by compütor or manually on paper. It is this logic that determines the criticality of activities, therefore you cannot have a critical path without continuous logic.



Regards



Philip

Razi,



The answer you seek is to do with planning software, not whether an ABCP exists! When did planning become solely a computer excercise?



The Greeks did planning when they were building the Acropolis, and I submit (provided the records were available) a decent planner could establish what the actual crtical path was throughout the job!



I think my 2 cents has grown to a dollar making the same point, so I’ll leave it to others for a while!



Regards

David

I hold the view a critical path can only exist in the as build stage before that it is only a projected/forecast critical path.





Cheers

Hi David



As per your logic "The connection between as-built critical path activities does not have to be physical, logical, resource dirven or otherwise - the connection is simply that it was critical at the time" than many or all activities could fullfill this criteria in isolation no doubt, but untill unless you do not connect them how you could you establish path leave critical or not.



I hold the view ABCP do not exist.



Regards

Hi Philip,

I think people are confusing Gerry’s question as being related to Primavera, Power Project, Microsoft Project or some other software, all of which require the relationships you refer to if a CP is to be established. He did not put his question in the context of software, and neither am I talking about software, forward / backward passes, early / late dates or the like.

The connection between as-built critical path activities does not have to be physical, logical, resource dirven or otherwise - the connection is simply that it was critical at the time (as reasonably and retrospectively determined -assuming of course it is possible to so determine from the available information).

Consider that an event that occurred (e.g. the collpase of a portion of structure) might make the crtical path switch between two completely unrelated unlinked activities.

In regards to the points made by others in regards to the ABCP as determined via software, I don’t disagree! Sorry about the double negative.

Regards
David

Hi Sigfredo,

I think the point you make is probably very valid, however, I have been in both camps, and still think that the ABCP is a figment of the imagination. Lets take it that the planner has regularly saved all the history including the float at every update and at the end of the project you tack every activity that was critical at any stage of the the project, and then try and find the connection between them. We have mostly agreed tha the critical path can jump around on most projects, so lets say tha you have now now isolated all those activities that was critical, the chance will be good that you may find they are unconnected. How are you going to explain that to a judge or arbitrator David?



Regards



Philip J

[Duplicate posting deleted by Moderator.]

[Duplicate posting deleted by Moderator.]

Sigfredo,



Interesting observation.



How about a survey to check your point?



I do not agree with the idea previously raised to ’agree to disagree’. For the sake of our profession, I think this important argument should be finalised one way or another.

Hi guys again,



It was suggested before that the issue be put to a vote. Maybe this is the right time to put the issue to a vote notwithstanding that the debate can continue.



It’s also noteworthy to see the trend of those believers in ABCP and non believers as to what background they come from.



Se

Hi guys,



Am i right on my observation that most who believe that As-built critical path comes from Contracts/Claims background while those on the opposite side are mostly Planning practitioners. Just asking



I’m on the planning practitioners side that’s why I believe As-built CP is not the right term and can not exist.



Se

Guys,



I am with those who think ABCP does not exist. My understanding of the CPM is that you do Forward Pass for the Early Start and Finish Dates, and then Backward pass for the Late Start and Finish Dates. Activities are Critical if ES=LS and EF=LF, i.e. when there is no Total Float. The fact that the Critical Path is the longest path in the Programme is the result of the previous process - it is not the definition of the Critical Path.



How can you do that with ACTUAL DATES??? in the AB Programme there are no Early or Late Dates - so how can there be a Critical Path?



Does your planning software (P3, SureTrak or even MSP) show a Critical Path for Actual Dates?



However, I am not sure about one thing:



In Contracts where the Contractor is entitled to EOT only for ACTUAL delays to the Date for PC, how do you know which delays actually effected the actual date for PC i.e. which delays were Critical?

Philip



As to your suggestion "agree to disagree", I’ve got two points:



First, while some in this forum have said the ABCP doesn’t exist, none have offered a clear reason why they reach this view. Your comments do however capture the matter which I think the following suggestion resolves?

Can we agree the ABCP exists (thereby answering Gerry’s original question which has stirred so much debate), while recognising that any view as to its route is subjective, i.e. an opinion?

Of course, an opinion is precisely how it would be appropriately characterised to a court / tribunal in any event (as Garry has recently done).



Second, it would be a shame to cut-off debate, so lets continue to canvass views. In particular I would really be interested in hearing clear justification for the view that it doesn’t exist as opposed to the point that its difficult / subjective to determine - any takers?



David

David

It’s not an IT answer. The point I’m trying to make is that As-built usually (wrt. drawings etc) means based on fact - so we can have as-built start/ finish dates. You say that determining the ABCP path depends on experience, common sense, etc. I totally agree. My point is now that we have a CP which is subjective - so whatever it may be it cannot be called As-built, its subjectivety should be admitted. Nothing wrong with that but it should not be called As-built.



I believe we have seen two (I think only two) points of view in this thread. Probably all that can be said has been said - we now need to agree to disagree!!

Philip



I think you are giving an IT answer to a planning question. Locating the as-built critical path is best achieved by the application of experience, skill, and common sense. The occasional and careful use of programming data and software (links et al) is a useful tool but only that!



The As-Built Critical Path must exist - its a matter of physics IMO. Had Gerry asked "is it always possible to locate the ABCP?" then subjectivity might reign!



David

It seems we are going around in circles here. Because a judge (or similar) thinks that he/she understands the concept of an As-built Critical Path does not mean it exists, or if it does that the definition is universally held.



The crux as pointed out recently is to show the longest path through a project after the fact. Actual start/finish dates can be said to be fact (if records are full and correct) but there is nothing factual about the links. If you can demonstrate the Actual logic then you can have an actual critical path, otherwise the CP is a mixture of fact and conjecture. One should be very wary of telling a tribunal (or similar) that a critical path that mixes post-project fact with original or amended logic is the As-built CP. We have presented pseudo-as-builts BUT with the clear proviso that the plan logic is reconstructed with best endeavours - not fact!

Having watched this thread with interest, it is clear that there are two distinct camps of thought here – there are those who believe an as-built critical path cannot exist and those who do use them. I have to say I am in agreement with Roger and David that an as-built critical path must exist, for people, me included, draw them as part of delay analysis and delay claims.



Having recently presented an as-built critical path to a judge in a delay analysis claim, that judge certainly believes in such a document and terminology. David is right when he says clients, courts and tribunals are constantly looking for assistance from experienced project planners on this subject. In my experience, courts do want to know what was the critical path through the project even though that project may have been completed a significant time ago. An as-built critical path is exactly what they are looking for.



Best wishes



Gary France

Chairman

Planning Engineers Organisation

I echo David’s remarks. In the context of this forum the ’As-Built Critical Path’ term is very important and fundamental to any time-related claims.



Gerry McCaffrey’s original question was, "I am trying to elicit views from real planners discussing the concept of an as-built critical path. Does such a thing exist?"



In my view it does; but it can not be simply generated from the original as-planned baseline network using the planning software in which it was created. IMO it is created from a thorough manual investigation of progress records and other documents. In reality this is the chain of activities that is the longest continuous path of activities between project start and project completion. However, in the ’claims’ context this is commonly known as the ’As Built Critical Path’.



Roger Gibson

Philip



Your sentiments are well voiced and received - but remember, you’re writing them in a forum entitled "Contracts, Claims & Claims Assessment". While no one can criticise your idealism I think you ignore reality - i.e. that it is (alas) often very very relevant to determine historically what was critical on a project at a prior point in time.



Clients, Courts and Tribunals are constantly looking for assistance from experienced project planners on this subject - surely you can’t be suggesting they are seeking answers to an impossible question?



A Happy New Year to you and all the other forum participants also.



David