I agree that as built critical path may not be a suitable method to use.

I can be manipulated to suit the claimnant interest. The manipulation could be brazen to the point of being ridiculous, fantasy

I have this experience where the commercial manager and project manager wanted to save their ass. So the instruction is to manipulate the as built critical path to show the client impacted the delays.

It was so IQ 0 that as an experienced planner, I decided to leave the project team for good.

Thank you,
Scarlett

10-4

Sreejish Vishnu

For your reference:

http://www.planningengineers.org/publications/papers_download.aspx?id=4

From above ABCP’S ARE OFTEN APPLIED IN CONJUNCTION WITH TIME IMPACT.

http://www.planningplanet.com/forum/forum_post.asp?fid=&Cat=7&Top=8238

Best regards,
Rafael

Ken,

Don’t disagree with what you’ve said and as you say, the CAB and IAP have less to go wrong, but they are also the easiest to pull apart and discredit. As the judge said in City Inn with regard to an as-built schedule:

"I am of the opinion… that an error in one logic link can vitiate the whole programme, and errors in a number of links will almost inevitably vitiate the programme.”

And common sense won the day in this one as far the method of analysis goes.

It’s not down to the experts to decide if the party has sufficient proof for its case, that’s the lawyers job, so as you say, experts will be asked to give an opinion on a case whatever the state of the evidence. In the case I referred to, the judge went out of his way to say the experts had done what was asked of them (para 240) - a dig at the instructing lawyers.

City Inn is also a case in my opinion that should have been thrown out for want of proof - now we’ve got a claim that has been thrown out for want of proof - potentially interesting times ahead. Other judges, arbitrators and adjudicators may follow suit. Food for thought for the lawyers but also for everyone else involved in a project - how good are your records?

All,

One other thing the case says, although not a decided point:

Para 179: Haswell submits that Mr. Crane has not correctly applied the time impact analysis method in that, rather than applying the impact of the delaying event himself and assessing its consequences, he has used Costain’s monthly updated progress programmes for that purpose and, after the correction of certain anomalies, has accepted those programmes as correctly showing the impact of the delaying event. Mr. Purbrick, on the other hand, has carried out what he considers to be the more correct approach, namely to consider the state of the progress of the works prior to the inception of the delaying event and then impacting that event on to that programme in order to see what the software produces as the impact of that event. It is not clear to me what difference to the actual results these alternative approaches lead to but, if it becomes material to decide, I prefer the approach of Mr. Purbrick.

Para 180. The reason for that preference is that it eliminates any subjective distortion or manipulation (either advertent or inadvertent) in the production of the monthly progress programmes by Costain. Mr. Purbrick’s approach seems to me to be more rigorous and to be more in accordance with the accepted understanding of a time impact analysis approach, as agreed by the experts.

i.e - the preferred approach is NOT to use the contractor’s monthly updates in an analysis as they may have been manipulated. So next time you’re tempted to manipulate your programme to support your company’s case, if it all ends in a formal dispute, just remember that those programmes will be consigned to the bin and you’ll be in the position of having to argue that your own programmes were wrong!!!!!

Have made this point in previous threads but it’s the first time I know of that there’s been some judicial opinion on it.

Hi all,

Time Impact Analysis (TIA) is often confused with Windows Analysis, since they both require the same basic information - that is a logic-linked as-planned programme (or updated version thereof) and as-built records.

The difference (though not picked up in the case text Andrew refers to) is in the periods of anaylsis. Where a windows analysis will set arbitrary time-periods in which to assess the events (usuallu monthly), the TIA will usually set the periods at the start and end of the delay events themselves.

Its a subtle difference but with TIA one assumes that the events are known, wheras in a windows analyis, the effects are established first and then the causes are legitimised if they fit.

As with all these things, it depends to a certain extent on the form of contract but more importantly on the information available. Of course a windows anaylsis or TIA is generally thought to be the "best" and indeed is the method recommended by the SCA Delay & Disruption Protocol. However, back in the real world, we rarely get a reliable and reasonable as-planned programme with logic links and decent AB information together. The other problem is that for all but the simplest projects, the TIA can get fiendishly difficult to understand without reliance on software. Whilst some still advocate this, it is preferable to provide your own expert opinion and avoid the "garbage in- garbage out" problem.

Just my humble opinion

Good post Mike.

Regards

Ken

Hi Mike

thanks for the thread

Case - 1 - As planned impacted method or TIA could be used.

case - 2 - TIA or ’As planned but for’ if possible. But I personally feel APBF would be very difficult to come out with.

Case - 3 - an as planned vs as built could be used. depending on the situation may be other methods could also be used.

Above are my understanding, off course I am not an expert on this.
What the experts say?
Also, i feel, to start TIA its required to have a properly updated programme and good as built records. otherwise the job is going to be really tough. Similarly if the as planned programme is crap then Impacted as planned would not give a good result

So i think the method would also depend on the availability of programme, as built records etc.

Mike

An interesting and worthwhile post, I agree that in my experience there is confusion as to what the specific terms imply.

Examining the scenarios you describe I would use the following techniques.

Scenario 1 demands a prospective technique I would use either Impacted As-Planned (IasP) i.e. impacting the delay event into the As-Planned or Baseline Programme, or Time Impact Analysis (TIA) i.e. impacting the delay event into the programme with the work done progressed to the time at which the event occurred.

Scenario 2 is retrospective analysis and As-Built v As-Planned (AB v AP) would be the preferred technique here.

Scenario 3 is complex, but I think I would be inclined to use IasP.

A 4th scenario worth considering is where there is no agreed Baseline, or where the works were not planned and no programme was prepared. Sadly scenarios which are still common place today. In such circumstances it is generally when the work is done (over time and budget) that a retrospective analysis is required. ABbF or Collapsed As-Built techniques could be used; also As-Built Critical Path (ABCP) is a useful forensic tool. Competent Planners are needed with these highly subjective techniques.

Not sure if I have picked the most appropriate techniques, but hopefully the results of your research and subsequent postings will resolve the issue.

Regards
Paul Hodgson