As Built Critical Path

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

Enthusiasts may wish to read the judgement of the Great Eastern Hotel Company Ltd -v- John Laing Construction which was issued 2 days ago.

At paragraph 307 the judge states "These are not paths which were identified by either party during the project itself"

Note - this is in connection with ABCP.

The judgement makes very interesing reading. The clear dangers of adjustments to logic (during and after construction) are discussed in a surprising level of detail.

Hi Gerry do you have a link to this.

Hi Jaco - sorry, forgot to put link in.

www.bailii.org

then perform search for "great eastern".

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

Sigfredo, I can assure you that the judge is not a fan of impacted as planned. Read paragraph 184.

Gary - did the judge get it right at paragraph 67? Seems that he’s describing a time-impact-analysis.

BTW - well done Gary. A short summary of your take on it would be interesting.

Regards

Gerry.

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

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

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

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,

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 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

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?

Keith

I think you were hard done to in the Egger judgement - probably in no small part down to your answer "Exactly my Lord" on page 171. I also know that this is the opinion of others whom I respect in this business.

That aside - I cannot see a clear pattern that you may refer to - other than 2 prominent drafters of the Protocol getting a bit of an ear-bashing in each case.

Whilst you have dipped into this thread - do you have any views that you’d want to share in relation to the question "Does an As-Built Critical Path Exist?". Tony Caletka wrote an article on it (without contributing to the debate!! Naughty.) Most participants consider this to have been a fairly interesting thread.

Regards

Gerry.

I am not sure I was hard done by but I am sure Egger were as I am equally sure Laing were.

In terms of similarities how about:

In Egger the the employer was found to have caused 100% of the delay to completion, the contractor and its sub-contractors being found to have caused none; in GEH the contractor was found to have caused 100% of the delay neither the works contractors nor the design team having caused any at all. Both results are inherantly improbable and contrary to experience.

In Egger the Judge found Egger had behaved badly by screwing the contractor down on price and then not giving it an EOTs during the course of the works. In GEH the judge found the CM had behaved badly by falsifying its programme updates.

In Egger I relied in the case of 2 events out of 120 on some evidence provided by my client and my analysis never got past first base. In GEH Tony relied on some of the evidence of his client and his was also discounted.

In neither case was the Judge aware of what was in the experts reports. In my case he was not aware of the content of my supplementary report either.

The two experts who were criticised and whose evidence was dismissed were, as you say, both on the protocol committee.

Are there any other similarities?

I did not mean to ignore you point on the AB CP of course I have a view but I don’t want to interfere in a spirited debate just to offer an opinion that frankly, does not add much because if you have the facts you can and if you don’t you cannot.

You have the skin of a rhinocerous.

I don’t take it personally. Heavens, if we did that how could we be impartial.

Certainly was not meant to be taken personally. Fact is, you have just about single-handedly propelled the issue of methodical analysis worldwide in the past 5 years - irrespective of competing views on appropriate methodologies. That’s a big plus.

Keith and all…

Thanks for your reply.

Who ever suggested it was anything other than a serious discussion? However, I stand corrected but knowing that you are a proponent of TIA and that the judgement refers to it as a ‘sophisticated impact analysis’ and ‘of some hundreds of pages supported by 240 charts’ I think I and others have made the reasonable inference that you were probably using TIA.

As I said previously, we need some definitions of the methods we use so that we can all learn and identify. Garry France was good enough to relate some of his experiences in GEH, in particular to help identify the methods of analysis that both experts used, I do believe, in that Judgement there was some confusion in descriptions.

Maybe you would like to enlighten us as to the method you did adopt? I do not think that is really the important factor here though. Some commentators have sought to suggest as a result of this case that sophisticated computer-based analysis techniques should not be used. That is a great disservice that has been done to our discipline whereas the real problem was the ‘unreliability evidence based upon his inadequate research and checking’ and other such criticisms.

So, do I recognise a pattern in Egger and Great Eastern Hotel cases? Yes, unfortunately, I do.

Regards

David

Keith,

You were not quite correct when you said “…in GEH the contractor was found to have caused 100% of the delay neither the works contractors nor the design team having caused any at all. Both results are inherently improbable and contrary to experience.” For example, in paragraph 131 of the judgment, reasons are set out for the delays not caused by the contractor (actually, Laing was a construction manager).

You also said “In neither case was the Judge aware of what was in the experts reports.” In GEH this was definitely not correct. It was very apparent that the Judge took a great deal of time to read both of the Experts’ reports and knew the contents well.

There are similarities between the two cases, but there are also significant differences, the main being one centred around the role of a contractor and the other the role of a construction manager.

Gary France
Mace

Seems the Egger case keeps coming up in various threads - hot subject of debate.

Firstly to answer the question, yes an ABCP can exist, trying to build it to reflect events with a high degree of accuracy is very very difficult especially retrospectively. It’s hard enough if your’e there at the time and know all the in’s and out’s first hand.

Secondly, KP and Egger, having read the proceedings a few times now along with some other articles I can only conclude that David’s comment on quality and reliabilty of evidence hits the nail on the head. Either KP was chasing a number of less than 100% justifiable claims on behalf of his client (now none of us do that do we) and so had to try and make the evidence fit the claim or the team putting the evidence together were at fault (or both). Also KP’s preparation and understanding of that evidence would appear to be questionable from comments made in the case.

As for the conspiracy theory put forward that authors of the Protocol are being singled out and systematically trashed by the legal system, I don’t really think so!!

Lesson to be learn’t - a claim put forward in a clear and concise manner with sufficient and proven documented evidence will win.

[Note from the Moderators: If what you intend to say is too impolite to type directly, why do you feel that it is acceptable to leave out the vowels but type it anyway? Does this technically absolve you?]

Guys, I think we want and need the participation of KP and other respectable persons, so lets continue to be professional and stop being personal. As for the issue of ’facts’, to what extent do you think the expert witness can rely on what he / she is being told by their clients (and reject the ’facts’ as presented by the opposing side)? If there is no sufficient documentation, how can the expert witness test these facts? Happy Easter from down under.

Hi Andrew,

Please explain how to build an ABCP any other way than retrospectively?

Uri,

I do not think it is appropriate to rely on the untested information gleaned from your client. Where it differs from that of the opposing side, the Expert Witness should either carry out his own independent determination or present a range of opinion covering both propositions.

Not sure what this all has to do with ABCP!

On that subject Great Eastern certainly makes it clear that the courts consider the ABCP exists - while there continues to be some disagreement in this forum on the subject.

I think Gerry summed it up much earlier in the debate when he said the disagreement seems to stem from the word "path" rather than the ability to analyse/identify what was critical on a project at any given time in the past (assuming as Keith points out the information is available to do so).

David
www.preceptpm.co.uk

Uri and all…

I agree totally that we do need the participation of as many PPers with knowledge, especially the specific and intimate knowledge, of the topics we are discussing. I also found your conflation of ‘respectable persons’ in your opening sentence amusing.

The Skanska case is important for planners and experts. Too few of these cases come to the TCC and are reported so widely. In a fast-moving discipline such as ours it is important that we know what the Courts are thinking, although they may not be precedents, they do give some pointers as to future conduct and what can be expected from expert witnesses and we all have lessons to be learnt.

It is also relatively rare that there is such a large amount of verbatim reporting in a judgement. As voyeurs we can only read the official reporting (lets say the Judgement in this instance) and what other learned commentators say about the matter. KP’s insight into the case is valuable as he has first-hand knowledge and is able, like Gary has done, correct some of our misconceptions or wrong inferences.

However what I object to is that you think some members of the forum are being too personal and not professional, you are of course entitled to your view but we need to share knowledge and respond honestly and openly to questions. In KP’s second posting of 22 March (I am not sure I was hard done by but I am sure Egger were as I am equally sure Laing were…) he makes some very pointed observations regarding the Skanska and GEH cases. I have only read the Judgements and reports on those cases, although I do know Gary, Tony and Jim, so maybe I have to make inferences and sometimes do jump to the wrong conclusions. If we are to believe what Gary says about the GEH then KP, it seems, is also guilty of coming to the wrong conclusions. I think it unfortunate that KP, in his subsequent replies, chose not to clarify my, and others’, misconceptions about what method of analysis he used in the Skanska case.

As for the issue of facts; it might be worth reading the SCL’s draft of the ‘Anti-Corruption Code for Individuals in the Construction and Engineering Industry’ (downloadable at http://www.scl.org.uk/papers/pdfs/121-stansbury.pdf). Section III, paragraphs 36 to 47 are about dispute resolution. There might be a few pointers here. It seems to me that it is acceptable to rely on ‘facts’ told/instructed by their clients so long as it is made clear, in the evidence, that is what is being done. As far as rejecting facts, that seems to me to be an oxymoron, a fact is either a fact or it is not (it could be an opinion, or an assumption or whatever else) and again so long as it ids being made clear that it is an opinion, assumption or whatever in the light of no supportable evidence then that should be okay. If there is no sufficient documentary evidence, statements by ‘witnesses of fact’ may assist here (rules and guidence can be found here: http://www.barcouncil.org.uk/document.asp?languageid=1&documentid=578).

As usual I should add that I am not a lawyer and my opinions may contain inaccuracies, inferences and downright lies!

Regards

David

David,
Your thought appear pretty spot on to me. I don’t think anyone is getting personal, at the end of the day two cases to an arguement were put forward to be judged, one won the day the other did not. It is just unusual in this case that the wording of the judgement was so damning of the evidence put forward by one side, quote:

"there were times when the impression was created that Mr KP was not entirely familiar with the details of the report....",
"..used untested judgement of others in selecting and characterising the data for input into the computer program...."

We can all run around being polite and bury our heads in the sand saying that nothing was amiss and that KP and crew were hard done by or we discuss the facts and learn by it. Discussing the polite niceities and ignoring the facts won’t learn us anything.

Hi Andrew,

I am still awaiting an answer to my question?

Philip,

Quite easy to build, not so easy to get right! If you update a programme (not the master, but a copy as you end up changing most of the links, adding lots and lots of activities, etc - do I hear a cry of horror from some people) as the project is built to reflect what has been done, why and what is remaining to do you will have a critical path at each update - part as built, part work to be done. So whats the difference I hear you ask from just updating the master programme?

It needs to be in ALOT of detail - I often build mine up from the daily plant and labour allocation sheets. Agreed it won’t show the whole as built picture and critical path until the end but it will demonstrate if done correctly a snapshot of the job at every update showing what, why, and when everything was done (I also like adding lots of notes to the programme)- very useful reference which can if required be compared to the master copy and it’s updates - they usually tell a different story as the master programme rarely contains enough information to get to the finer detail.

People don’t like changing the baseline master programme logic or activities for obvious reasons, some of which have been expressed in here, however I have sat with many a client / claims expert and produced the "alternative as built" programme and used it to demonstrate the course of events, normally backed up by documentation both during and after the project - haven’t had one take me to court yet!!!

People seem to get hung up on the master programme and believe it to be the only programme you can use to prove your case. Not entirely true - although it does normally carry greater weight than others - but if you can demonstrate that the other programme is a true reflection of events, then it’s as good and relavent as any other evidence - coming back to Egger (sorry) but right is right, wrong is wrong and you can dress something up as much as you like but you won’t beat a right call presented properly.

It has given me a considerable pleasure over time to unexpectedly produce to others a very detailed as built programme when discussing events / claims - the conversations tend to be quite short after they see it!

To get to your as built critical path Philip takes alot of work and time if it’s going to truely reflect events and therefore be useful. Strictly speaking, no you don’t have a complete ABCP until the end of the project but believe me, having that a part built one available at any time during a project can prove very useful. Hope this helped.

PS Phillip, apologise for some of the grammar in that last post, but then I have just got back from the pub!

Hi Andrew,

I forgige the grammar, simply fot the sake of practicbility or alternatively pragmatism, this thread was hi-jacked by the lawyers, and forgot practical things.

Regards

Philip

I have disagreeed with ABCP since the birth of the thread

Philip,

So what’s new

Hi andrew,
Thanks for the suppott, it is like finding the "Holy grail", let’s be practical/

Philip,

Not one of those who believe that there is ABCP was able to convince me as well.

If I go back to one of my posts, I proposed to this forum to get statistics on who believe that there is ABCP and those who do not. Moreover, I would like to know which field of specialization they working on.

Cheers,
Se

Sigfredo

With the greatest respect, who made you the forum Judge? The burden of proof is not on one side of the debate. It would be more interesting if you put down arguments and logic why you think the ABCP doesn’t exist! Or is your point, simply, that since we’ve failed to convince you then it can’t exist?

My sense of the statistics you would get from this forum are that:
1 the substantial majority say Yes,
2 the courts say Yes
3 Philip and one or two others, to their credit, justify a No position
4 A number of people have changed their views from early in the forum.
5 We all agree a practical approach is better than computer jockey planning

Come on you nay sayers, let us hear the arguments for the No campaign. Oh, and laywers begone!

David

Philip (J)

When I started this thread – it was my intention to issue a follow up question to address the uses that the ABCP (if it exists) can reasonably be put to. I did not get off first base as there is much disagreement as to the answer to the basic question – “Does an ABCP exist?”. It is also clear that in reading this thread that contributors have, in general, thought deeper on this issue than perhaps they have before. I also include you in this.

If I understand you correctly, your posting of 29 Jan 2004 at 14:14 indicates that you admit to the possibility of an ABCP. You state :

“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”

Why did you write the words “is near”. Why not just say it is impossible?

I suspect that as you focussed upon the matter to write your posting you realise that it is not impossible – but is highly improbable that it can be proved in detail on substantive projects.

The fact is – the question is too simple. Canvassing & formalising Yes/No responses from contributors to the thread will be of limited value. That is why I asked you to construct a question which may yield a useful result – your suggestion was amusing : -

"Is there merit/purpose in finding this so-called (mystical) AS-BUILT Critical Path?"

Your question may have prejudiced the result!!!!

Much that I hate the phrase – “each case on its own merits” - it is so often the case in delay analysis that this is true.

In my view - it would be foolish to conclude that as a matter of principle the “as-built-critical-path” does not exist. For one thing – the phrase lacks definition and means different things to different people. (and I mean different planners – and this disregards the entourage of other professionals with vested interest). Look at the views of you and Jaco – poles apart – but both logical practical practicing planners with a highly developed and keen interest in the subject.

Sigfredo – can you construct a useful question which will take cognisance of

(a) the complexity of the project which respondents to the question are to conceive in their mind.

(b) the level of detail to be considered in the as-built-critical-path? (i.e activities comprising of durations of days or weeks or months?)

It is my suspicion that a useful question will be at least a short paragraph. Long questions make for more debate (and look where we’ve got to with this little stinker of a question!).

The usefulness of the answers will be blunted by caveats like – it depends on the information available.

Gerry.

David Barry,

I say nay - as planning by definition refers to the future, and critical path is a planning concept, whereas AB is merely a record of what happened (i.e. past) in the project.

Garry France in his post from 7 December 2004, 18:19 provided us with an excelent example whereby prospective and retrospective analyses can lead to completely different results.

the AB in my opinion can not go together with the CP.

I think an AB v AP analysis is not in accordance with most forms of standard contracts, requiring a retrospective analysis.

Uri,

Good point, but one that I think is relying on semantics.

Can I pose a question to you -

1. Forgetting the word "path" for a second, and assuming excellent records exist, do you think you could work out what was critical to completion on Day 59 of a particular project that was already complete?

If your answer is Yes, then surely working it out for every day will represent the as-built critical activities throughout the job? This would be the ABCP, though perhaps another term for it might help.

If your answer is No, please explain why?

Philip / Sigfredo - what would your answer be?

David

Hi Planners,

Some really interesting points in these threads.

I have constructed as-built programmes on a number of occasions for producing collapse analysis and that is all.

My question is, if an As built CP does exist, and I am not sure it can be reliably determined, to what use can it be put?

(Loaded question)

Regards

Paul

Well claims persons, if you can’t look back at a project and determine what was a critical activity at a peticular point in that project then I’d have a long hard think.

EOT’s usually attach themselves to a critical activity or one which becomes critical due to the delay, so if you can’t identify them or they don’t exist what else leads to a EOT becoming due (in general)?

Andrew,

Answering your questions:

’Well claims persons, if you can’t look back at a project’

To me, it would be wrong to look back, you have to "go back" in time and then look FORWARD in order to decide what was critical at the time. I do not think there need for ’a long hard think’.

I can identify critical activities, but I’d use the currect programme when the delay occurred (or became evident) and not the ’ABCP’, which to me does not exist.

Hi Planners

The point of my earlier question was that if in order to create an as built programme you need very good records and information i.e. a regularly updated programme with actual dates etc. I really don’t see the need in producing an as built programme with subjective logic which would only produce one longest path (can’t be a critical path if it is a historical document).
In a live regularly progressed programme the critical activities can change from update to update, and this is the key information that is most useful and reliable in a claims situation.
If the programme is properly administered and maintained as it progresses what better information do you need? In most cases claims do not become an issue if you maintain records good enough to produce an as built programme.

If a claim situation arises then any analysis that is produced is prepared against a programme that the client most likely reviews on a regular basis as part of the reporting process and not a programme produced purely in substantiation of a claim.

IMHO an as built critical path sounds like a chocolate tea pot.

David B.,

1. Forgetting the word "path" for a second, and assuming excellent records exist, do you think you could work out what was critical to completion on Day 59 of a particular project that was already complete?

YES.

If your answer is Yes, then surely working it out for every day will represent the as-built critical activities throughout the job? This would be the ABCP, though perhaps another term for it might help.

WORKING IT OUT FOR EVERY DAY WOULD BE MEANINGLESS AS THE CRITICAL PATH MAY CHANGE DURING THE EXECUTION OF THE PROJECT I.E. THERE IS NO SINGLE ’OVER-ALL’ CRITICAL PATH. RATHER, THERE MIGHT BE AS MANY ’CRITICAL PATHES’ AS YOUR ANALYSIS POINTS...

Uri

Now we are getting somewhere!!!

But come on - if one can work out what was critical for every day of a project how can that be meaningless??? I think you’re being coy, and simply unwilling to abandon your previous position.

The identification of what was critical in retrospect is a vastly meaningful conclusion. If you were to successfully present that conclusion alone to an arbitrator / judge, you would be carried from the room atop shoulders with clients and lawyers slapping you on the back as you departed. Same for the site, where EOT’s haven’t been dealt with instantly.

Linking all the days together would identify the ABCP (- = activity and + = critical).
+++++++----
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And there is no problem with having concurrent criticality!

Regards
David

If you keep a history of project schedule versions you will know all activities that were considered critical in the past.
They may belong to as built critical path or not. In any case both information is useful for the project performance analysis and lessons learned.
Does anybody think that this information is useless?

Wow! Just a fascinating thread! And from my point of view, very serendipitous, as I’m currently co-authoring an article which incorporates the very idea that Vladimir argued: that every project has a CP, whether or not CPM is used.

I went back and read the whole thread. Here are my thoughts:

1. I one hundred percent agree with Vladimir, David and others who feel that there is such a thing as an ABCP. I think part of the problem lies in the mis-definition of the CP (by many authors and authorities!) as the path with zero float. We all know that, during implementation, a path might have either positive or negative float (supercritical). Even during planning, the longest path can have float due to calendar-based schedule constraints (No Earlier Than). Is such a longest path still "worthy" of being called critical? Absolutely!

The reasons for calling the longest path "critical" are not limited to (1) the fact that it has no float, so that if it slips, it becomes longer -- two other reasons, equally important, are that (2) the longest path determines the length of the project, and (3) if you want to shorten the project, you have to shorten the longest path.

Both (2) and (3) may have relevance for the post-project analysis: (2) in the sense of the ABCP, and (3) if the question ever becomes why were actions not taken that could have shortened the project (or avoided delay) by addressing the DRAG on the activities on the "currently estimated CP".

Thus I completely agree with Vladimir: EVERY project has a CP, whether planned using CPM or not, because it is that CP that ultimately determines project length. In fact, the ABCP may be called the "true" CP; during planning, what we are really dealing with is the "estimated" CP. Yes, our estimated CP may move around, as either scope changes or delays occur, or as duration estimates turn out to be wrong.

Surely it is HUGELY important, from both liability and knowledge database points of view, to know when, how and why our estimates of the CP changed? And whether, at any moment, our estimates were based on best available data, or simply on incompetent performance (either by contractor or client)?

In another thread, there was a question about whether a computerized "expert system" would ever be able take over the planning function. I expressed doubt, at least for the near future. But let us think for a second about a "perfect" planning system -- would not that system be, in fact, a crystal ball, allowing us to perfectly foresee what would happen (scope changes, client delays, fragnets, resource shortages, etc.) and incorporate them into the plan so as to have the best (i.e., most profitable) project?

And finally, would not the plan that the crystal ball created be, in fact, the ABCP?

Hi Guys,

As I originaly stated I do not believe that anything that is completed can be critical. I also have a problem with the name ABCP, it should probably be called something like delay analysis.

If the planner who was responsible is doing the analysis, ie writing a report on the problematical activities or areas, I would tend to believe the accuracy of the facts, dependant on the quality of the historical data, and planning. But where another party, that was not involved inyimately with the planning or the project, during the execution thereof, I would write it of as hearsay or conjecture.

Regards

Philip

Hi stephen,

The question is not what critical path is, I agree with you during the execution of the the project, however, when the project is complete, it is something like an post mortem, how can you find an ilness in a corpse, that is critical, you can only analise what the problem was and try and prevent in the future.

Regards

Philip

Philip

Hearsay and conjecture - I agree we don’t want that.

But what about what Gary F did on GEH - an objective, practical and thorough analysis of the FACTS (including identifying the route of the ABCP)?

By the way, to hearsay and conjecture I would add dynamic programme analysis (particularly Time Impact Analysis) undertaken without due care.

David

p.s. what are your answers to my earlier e-mail?

Phil,

With your use of the words “I do not believe that anything that is completed can be critical”, I would have to agree. It can no longer be critical if it is complete – that makes perfect sense.

However, I am sure that you would agree that it can be said that something was critical in the past. It’s not critical now, but it was earlier. That is of course if it was on the critical path that ran through the longest chain that determined the overall project completion date, or phased completion date.

I cannot agree however with you last paragraph. To say that only the planner who was involved in the project can determine the true accurate facts is clearly wrong. I will quote the example of the Great Eastern Hotel project referred to below in this thread. The judge found that the planner who was involved in the project got it wrong and this was exposed during the trial by a 3rd party planner (me) who was not involved during the project and who only became involved after the project was finished.

David is quite right – very often the independency of a 3rd party planner can see the situation better than the planner involved at the time. On the Great Eastern Hotel, I and a colleague spent over a year examining the facts to determine where the critical path actually ran through the project. Hearsay or conjecture – no way!

Gary France