AACE 29R-03 is flawed:
1) AACE 29R-03 makes continuous reference to float values instead of just using the software to show cause and effect which shall be the same, no matter if your software can or cannot display correct resource leveled float values.
It is wrongfully biased in favor of Primavera products, ironically products that under resource leveling cannot yield correct float values while others can correctly display resource leveled float.
2) To make it even worse the recommended practice embed the concept of Longest Path into the concept of Critical Path, a concept that includes activities that are not critical as they still have float, by definition is wrong as the added activities still have some float and can still be delayed without impacting the project finish.
Still the meaning of float shall be the potential delay that does not postpone project finish or due dates. Well incredible but true, Longest Path misses resource critical activities.
What is even more of a joke is the fact that in page 9 of the AACE 49R-06 Recommended practice for identifying the Critical Path, the authors make reference to Primavera Software and say "This RP assumes that the algorithms used in each of these implementations are identical and give identical results."
Seems like the AACE is unable to validate the correctness of Primavera products when a single wrong result would be enough to prove its unreliability. Making reference to a product you cannot validate is irresponsible.
The implementation of Longest Path by Primavera products is flawed and can be easily demonstrated by modeling a four activities job, each activity independent of each other and using a single resource of which only one unit is available. After resource leveling Primavera products will give wrong float values, and even when P6 yields in this sample job correct total float, the values of free float are wrong. Incredibly neither P3 nor P6 will display a continuous critical path and in some occasions can yield a single activity Longest Path that can even be non critical. Beware that in other schedules P6 can yield wrong values of resource leveled total float. Longest path will not always provide you with a continuous path as frequently required in the recommended practice. If because of different calendars or resource leveling the critical path is discontinuous then let it be, just keep the correct mathematical meaning of float. Saying critical path can be this or another thing just bring confusion and is wrong.
3) The inclusion of negative float theory into the practice is inappropriate in delay analysis protocols, negative float hides schedule logic to the extent the forensic analyst and many schedulers disable the constraints that create negative float.
Still the AACE 29R-03 requires to consider negative float and this results in very cumbersome exceptions to be applied, for example;
under one of the many delays methodology,
Excusable & Compensable Delay (ECD) - The difference between the as-built completion date and the collapsed as-built completion date resulting from the extraction of all owner-caused delays is the total ECD. If the owner has paid the contractor specifically to accelerate, then any negative delay durations (delay mitigation) resulting from the owner-paid acceleration should be credited to the owner against the total ECD to avoid double payment to the contractor for acceleration. Where the quantification of the duration of the specific paid mitigation is not reasonably feasible, the credit adjustment may be accomplished by crediting the monetary value of the acceleration payment against the monetary value of the ECD.
or under other delay methodology,
Excusable & Compensable Delay (ECD) - The difference between the as-built completion date and the collapsed as-built completion date resulting from the extraction of all owner-caused delays is the total ECD for each modeled time period. If the owner has paid the contractor specifically to accelerate, then any negative delay durations (delay mitigation) resulting from the owner-paid acceleration should be credited to the owner against the total ECD to avoid double payment to the contractor for acceleration. Where the quantification of the duration of the specific paid mitigation is not reasonably feasible, the credit adjustment may be accomplished by crediting the monetary value of the acceleration payment against the monetary value of the ECD.
... and the workarounds to deal with negative float are endless, what a mess !!!
To prove cause and effect, negative float is unnecessary, it just adds to the confusion. It is enough to make proper reference to criticality as defined under the contract and use procedures that do not depend on the use of negative float, procedures that do not hide schedule logic.
- If the dominant cause is defined on the contract to govern, what some call “longest path” then be it.
- If delays on already critical activities but not dominant is defined on the contract to govern criticality then be it.
- If the contract apportions some float to both parties then be it.
- If the contract is not clear then common law interpretation in favor of the party that does not write the contract shall prevail.
4) The basic principle of cause and effect is still valid, the recommended practiced shall concentrate on using the CPM model to prove cause and effect in a way it does not depends on flawed theories, in a way it allows for the use of software that even when correct values of resource leveled float are not displayed as this does not necessarily invalidates the analysis. It shall not rule out software that provide better functionality with regard to the implementation of constraints and still identify all critical paths avoiding the use of negative float because it hides schedule logic. More advanced software that implement “finish not later than” constraints in a way it identifies criticality without modeling the impossible and without making possible the creation of wrong progress curves that at times might cross each other.
The precise numerical value is not as important as the absolute delay calculated when measuring the planned completion date to the projected completion date. From, Delay Analysis in Construction Contracts P. J. Keane & A. F. Caletka
The industry needs protocols that do not favor or advocate particular interests, particular egos or particular software.
Best regards,
Rafael
Rafael and Mike:
I am disappointed at the way you are dealing with this issue, and the links that you have provided here and in your email to the AACEi are both to the original, outdated versions of the RP. If you go to the AACEi, you would find the revised version available for download at no cost. And coincidentally enough, we got word yesterday that the most recent revision was approved by the AACEi Tech Board, so that should be posted on the website in the next couple of days.
In addition, access to the AACEi Forums is free, you just need to register at no charge and do not have to be a member. I hate to see you so upset over a misunderstanding of the Forums; I'm not sure who told you that you had to join AACEi to participate in the Forums, but they did you a disservice. We invite all professionals to participate in the review of the Recommended Practices, that's the way we improve the quality of the products.
As one of the three Authors for the most recent version, I can tell you that the RP has been in constant review and upgrading since that first edition was released in 2007, four years ago (not to count the three years spent in compiling the document before that). In the most recent revision just approved, we spent over a year in soliciting and collecting comments, and six months in correlating and reviewing the hundreds of comments that we received. I can assure you that any egos that might be involved have been thoroughly tested in the process of soliciting and reviewing comments, and no one has been able to force their sole point of view on the RP. Certainly, all of us have various viewpoints on different issues and not all of them have been satisfied in the development. However, we believe that the document has been thoroughly discussed, vetted and revised by a large group of very knowledgeable experts, all of whom have devoted our time to the development, not for any egotistical need (as far as I can tell), but rather to help improve the industry. For me, my primary motivation has been to try to provide a document that will make it harder for the hired guns and one-trick pony consultants to develop and push fairy tales that are not supported by facts. I suspect that your motivations are similar. Everyone is and has been welcome to participate in the development and edits to the RP.
All three of us that are Authors of the recent revision, Kenji Hoshino, John Livengood and myself, are currently at the PMI College of Scheduling Annual Conference in San Francisco, as Roland mentioned. We received a forwarded copy of your email to AACEi yesterday and have started a response, and should have a detailed response out shortly. I think that responding in less than a week is pretty good considering we are all very busy between the conference and our workloads.
So, I hope that you both will consider this response in the manner in which it is offered; we are very open to constructive criticism and welcome your participation in any of the RPs. There are some very dedicated and knowledgeable experts working on the development of the RPS, like Ron Winter, noted above.
Thanks,
Chris Carson
Rafael,
Your dilemna is that you are forward looking and the others seem to try to catch up. That is the normal order of things.
I agree that resource loading/leveling affects claims greatly and this has been mostly ignored maybe because it was easy to just assume resources are unlimited....
I had a peek once on the new AACEi RP 29-03 , not sure when is it supposed to come out and I remember the first impression I had was : Too Much Gibbrish.
I have to admit that writing clearly is hard though. I'm finishing up the Draft for the "Schedule Reporting and Response" Topic for the new PMI's "Best Practices and Guidelines for Scheduling" and honestly I don't think I did a great job (actually I think I just kept repeating myself but maybe thats whats needed these days).
Writing under stress , especially when you're already overloaded with work and problems can be Hellish :)
What is the best resource leveling algorithm you have used so far?
Best Regards,
Roland
Roland,
About your curiosity,
"I was curious about the timing of your post though. Have you not previously noted the problem in the AACEi RP? This document has been around for a while now."
I have seen the document before, but never paid attention to it other than comment about how many TIA's are there and that the document wastes time mentioning them, to me it is unnecessary for the author to compare his recommended practice with others in the same document.
I make my living rendering engineering services, scheduling is my sideline, is kind of a passion.
In the few occasions I use scheduling to prove some negotiated claim I usually use some form of TIA, avoiding the AACE recommended practice for it as it is self-serving on its apportion of the risk on float. It says that float (either by contract or standard default, whatever this means) belongs to whatever party uses it first. It forgets it is not necessarily so, that if the contract does not apportions float then cause and effect governs. If by reducing float latter on it happens this put into a difficult or impossible position for the Contractor to finish on time then there is some liability by the party who used float in detriment of the other no matter the timing.
This is a concept, many Owners and those having interest on representing Owners pretend to legislate into "Common Law" by means of continuous repetition, something I cannot accept unless the contract is clear or in such cases it was not foreseeable. Just imagine what would happen if out of a thousands activities the owner takes all float for himself and then you are required to deal with a job 100% end loaded. But this is another never ending issue the AACE International should have avoided.
A couple of weeks ago a client came to me asking for some assistance for a court claim, something new to me. I said let's see what I can do and started searching for the status on the forensic trade. I started with the first document that came into my hand AACEI 29R-03 and soon I saw it calls for cumbersome manipulation of negative float, that I did not liked. I also noticed that it also required a continuous Longest Path while referring to P3 a software I believed would yield discontinuous Longest Path under resource driven schedules, therefore considered the recommended practice to be flawed.
I opted to look for other references and found a reference about the Modified Windows Methodology, seemed like appropriate for the need and for the moment I am still on my research for the most adequate methodology based on what we have on hand.
I decided to call it to the attention first directly to the AACE International, could not get through and started the debate on PP first to inform the community of this, secondly to get some reactions as I was wondering what if the other side asks me in court about using the AACE International instead of re-inventing the wheel. We must know if it is flawed or not as there is a possibility it can cause us a lot of damage.
We use software that does not cerates such an aberration as negative float as it hides true logic. The other problem is with the implementation of "longest path" as our software has no need of it for showing full critical path after resource leveling. We consider displaying of a few non critical activities along the path unnecessary, perhaps a distraction as they are not truly critical as there is still some available float, including these is plain wrong, so the theory of longest path meaning critical path even when continuous is flawed. To us it is more of an ego issue by some members of the AACEi rather than true need, it needlessly complicate things, it cost extra and might divert the attention of the court.
As Mr. Obama sid a couple of days ago, " get back to focusing on the issues that matter, like, ‘Did we fake the moon landing?’ ‘What really happened in Roswell?’ And ‘Where are Biggie and Tupac?’ ".
Best regards,
Rafael
Yeah i didnt see it at first but i edited my reply after i saw it
Haitham,
I have actually already done the exercise with P6 and posted results in one of my posts (includes Graphics). Check it out.
Sure, I will do it tomorrow when i get to office...Actually you made me curious about this issue.
Oh I didn't see Roland's post...so that means that the P3 is faulty in the longest pass and they solved that issue in the P6
Rafael,
Its weird for "all" the threads to be closed. I will check into that.
You call what the RP did an error , some others seem to call it reference to softwares with the biggest market share. While others like me prefer to simply state:
"things take time , the RP isn't set in stone."
I know the ACI codes pretty well. fun stuff except when some project specifications start using them as standards while they are supposed to be more like recommendations. I've had to refer to them on many occasions especially concerning the cycle for a Drop-Head Slab System in one of the projects.
Concerning the GSA and other such organisations. There are always ways to approach these firms or organisations, regardless of their size.
The following is a bit out of context but somehow related. I have previously noted that some of the other brands, not all of course , do not follow proper Marketing Techniques (and by proper I don't mean paying millions of dollars , I am talking process wise) . In addition they do constantly make the mistake of confusing Marketing with bashing your competitors. One is not really promoting the value in his product by constantly bashing his competitors. It should be more about changing the Market's perception and putting out your value proposition to your prospective targets. Lead generation and conversion is a complex system.
I have previously tried to tell some of the other Scheduling brands that they needed to alter their marketing strategy to compete for a bigger market share. Unfortunately, a lot of them are not familiar with Business processes , not really interested and are more technically oriented i.e (the whole team is made of engineers not really interested in Business Stuff.) The only thing they seemed interested in doing was Bashing others.. Not very convincing.
Anyway I think it is possible to approach these organisations, its only about adopting the right approach, being patient and trying to stop the constant Bashing.
There are already many individuals who have written about the flaws in delay analysis techniques that do not take proper resource leveling algorithms into consideration (like the articles we both posted).I was curious about the timing of your post though. Have you not previously noted the problem in the AACEi RP? . This document has been around for a while now. (There is another version coming out I think).
Best Regards,
Roland
Roland,
But they make reference to P3 and Microsoft Project, there is no excuse for such error.
About the bias with Primavera products, it is there, I am an engineer and know more complicated practices such as the ACI Code, The American Concrete Code. Today everything is controlled and calculated using computers but the ACI had no need to make persistent references to particular software. I believe that relying on particular software to show what shall be generic is laziness. Particular software belong to places like PP not on a "software neutral" document. Is obvious their bias in favor of the software to the point they take time to explain some minute details particular of the software.
As per your suggestion I tried to post into their forum but could not do it, found all threads closed for posting. As I told you before my experience with some of these institutions is that they do not care; for example the GSA, they are too big. No longer naive, the only way I know that maybe, maybe someone will notice is by doing something different, by calling the attention. And here jokes call the attention.
Here we love jokes and making fun of public figures, a few nighs ago I even hurt my stomach by listening at the jokes Mr. Obama made about his own, just in case is good for you to know his official birth movie was a joke, it was a clip from the movie The Lion King. I even enjoyed watching the face of Mr. Trump although here we all appreciate him because he invest on local Hotels and brings money and jobs.
http://www.youtube.com/watch?v=Gv_44QQMcGo
Sorry, but the AACE International got it so wrong about the implementation of "Longest Path" in P3 and MSP that the temptation for a joke is too much.
For some reason you are starting to remind me Mr. Trump.
Best regards,
Rafael
Rafael ,
Please do not repost the statement I've quoted. It's just redundant. Keep the sarcastic comments out if you want people to perceive you as a professional. Thank you.
No offence to anyone , but if you had to include something software dependent, I think choosing the Software Packages that have the the biggest Market Share, regardless if they are the best or not, is the normal choice. There is nothing wrong with that. This doesn't show bias. Its reasonable. You cannot reasonably expect them to include "all softwares" or those who have a much lesser market share, regardless of the fact if they are better or not.
The authors of the RP have not just disregarded or ignored the flaws, since a lot of them have written about those flaws on a parallel track! They have reasons for not delving into this complicated topic in the RP itself. I have already told you , you could try to post on the AACEi forum, as long as its respectful , get a response as to why and then decide whether this response is convincing to you or not.
I am not gonna repeat the above.
P6 seems to level the resources using the Longest Path definition of the Critical Path without breaking the path.
The reason is that Primavera has added an option called preserve scheduled early and late dates shown below that results in the resource-leveled schedule shown even lower (Longest Path option used)
[[wysiwyg_imageupload:449:]]
[[wysiwyg_imageupload:450:]]
Read the following statement from page 101 of the recommended practice
"The policy of this RP is to be ‘software neutral’. This means that procedures and recommendations are made without regard to the brand or version of software used for analysis. However, the examples of techniques used to manipulate results, listed below, contain descriptions of the features taken directly from the software manufacturer’s manual in order to accurately represent the techniques which are software-dependent. Two major software products, Primavera Project Planner (P3) and Microsoft Project (MSP), representing a significant market share of the scheduling trade, were used as references."
Are you going to tell me they based the whole document on two products that do not have corect implementation of "Longest Path". That AACE International did not know "Longest Path" implementation of P3 was wrong and now, that they did not know MS Project has no built in implementation of this thing.
Project Planner (P3) and Microsoft Project (MSP), Project Planner (P3) and Microsoft Project (MSP), Project Planner (P3) and Microsoft Project (MSP), Project Planner (P3) and Microsoft Project (MSP), Project Planner (P3) and Microsoft Project (MSP), Project Planner (P3) and Microsoft Project (MSP), Project Planner (P3) and Microsoft Project (MSP), Project Planner (P3) and Microsoft Project (MSP), Project Planner (P3) and Microsoft Project (MSP), Project Planner (P3) and Microsoft Project (MSP), Project Planner (P3) and Microsoft Project (MSP), Project Planner (P3) and Microsoft Project (MSP), Project Planner (P3) and Microsoft Project (MSP), Project Planner (P3) and Microsoft Project (MSP), Project Planner (P3) and Microsoft Project (MSP), Project Planner (P3) and Microsoft Project (MSP), Project Planner (P3) and Microsoft Project (MSP), Project Planner (P3) and Microsoft Project (MSP), Project Planner (P3) and Microsoft Project (MSP), Project Planner (P3) and Microsoft Project (MSP), Project Planner (P3) and Microsoft Project (MSP),
Or is the above statement in French.
My friend, their software bias is so obvious in my barrio people would say it is so obvious the seams of their butt can be seen at plain sight.
Hello,
You have to admit that this statement , contained in the RP, has to be given consideration:
Plase display free float to see if they are correct, I know in this particular array it would yield correct float values.
Also please display critical path as defined per "longest path" not as per "total float" as some Primavera products claim they are different thing but if you want you have the option to make it whatever of the two.
Remember I am still waiting to learn about "longest path" as implemented by MS Project, as the recommended practice makes reference for it to be based also on MSP, as if it is enough to show they are not biased in favor of certain products.
Thanks in advance,
Rafael
Well, I have tried that on P6
[[wysiwyg_imageupload:443:]]
http://www.ce.berkeley.edu/~ibbs/BRICS/Materials/Nguyen_Ibbs_DelayAnalysis_2006.pdf
Here most significant delays have a huge impact mostly because of resource availability, suddenly all activities are opened up but there are no enough resources to make them happen at the same time.
I do not agree with the AACE International procedures that do not allow for resource constraining by means of requiring a continuous longest path. It is in error, it is thinking of the 1960's, resources do matter in delay analysis.
Hi Rafael
In my experience resource levels rarely come into a retrospective delay analysis and if they ever do it would be by comparison of planned deployment and actual deployment - an excercise which invariably leaves to contractor with the accusation that the project was under resourced from the start.
In which case a resource levelling excercise would be purely theoretical and irrelevant.
I have never yet come across a contractor's programme that was resource driven so I have to set up my own resource modelling based on the Cost Plan / BOQ and then only if a disruption claim is contemplated.
Best regards
Mike Testro
What?
Suddenly after issuing the recommended practice they figured it out P3 is wrong? How come they did not figured it out before? Can you trust such procedure?
What MS Project has longest path? Where, how?
Suppose before P3 "longest path" was not necessary or so irrelevant to the point no one noticed it was flawed?
Are all delay cases prior to Longest Path after P3 to be reviewed?
Longest path does not add much into the discussion in court, it ads unneeded complication to all the parts, such practice lacks sensitivity to the needs of our courts. If you present your case using such cumbersome theory, especially the theory on negative float, the judge might not get it so you might loose making him understand your point and so you will not be able to prove him your case, the burden of proof is always on the claimant. If not convincing, if too far from common sense the case most probably will be lost.
If you got my sample file probably we can do some testing with P6 to see if it will yield a "longest path" continuous from start to end without using old float teory, and perhaps we can even make it a bit more complicated as this is maybe too basic, maybe by trial and error the software developer is figuring out how to solve the easy ones.
And even if it proves not to be wrong, insisting in complicating a court presentation way above needed is wrong, it shifts the focus from the central point to unneeded technicalities a judge is not trained to understand.
In addition ruling out software technically superior that do not follow the game of negative float because it hides logic or do not follow the game of longest path because it is not much what it adds is plain wrong.
Well hope you will help me with the testing of P6 as I do not have a license of it. Just start by transferring into P6 my sample job, run resource leveling and tell me the displayed values of total versus free float to see if they make sense, then tell me about the display of a continuous "longest path" from start to finish without using total float as critical path but longest path.
Best regards,
Rafael
It is good Caletka and the British speak English, at least with them I am getting good references.
Hello Raf,
Concerning our subject.
What do you think about the Ron Winter article concerning "longest path value"? He does mention in that article that P3 Longest Path Implementation doesn't work.
did you have the time to look at the concept and maybe do a bit of verification on your end?
Its this one:
http://www.ronwinterconsulting.com/Longest_Path_Value.pdf
Best Regards,
Roland
PS: FAR is far from reality :)
This is not Europe but USA territory, our laws regarding government procurement differ to private procurement. There is a Federal Regulation known as FAR that prohibits brand name specifications by government unless there are very special conditions.
http://www.cohenseglias.com/government-contracts.php?action=view&id=264
Unfortunately many in federal government do not care, therefore they are frequently cited to federal court. The problem is that they are fast learners and do it in a subtle way by preventing services and material suppliers to issue claim in court unless they are direct bidders, therefore a supplier of specific software or specific brand of toilet tissue dispenser cannot present a claim.
I will try your suggestion but without much hope, I believe the reaction will be similar to GSA that had declared me before with no standing as I am not a direct bidder.
I love my country and my system but I am no naive, it is far from perfect.
There is freedom of contract as long as it is not against the law, in government contracting brand name specification is against the regulations that have the effect of law. That we have people that break the law is another thing, government employees are not the exception. That I have an issue of standing with my claim does not mean the GSA is correct.
The longest path computation is flawed because it misses some activities, it can only identify activities on a path tied by logic links, if the continuity is broken by resource leveling it get lost.
As a matter of fact if you look in detail my postings my point is that precise values of float are not needed in order for the software do its modeling, here I am not making an issue about resource leveled float, it is important for the management of a schedule, it is important for it to be correct for you be able to perform good management but it is not an absolute need to keep the forensic results correct.
I believe Vladimir is concerned about the value of correct float determination, but believe he is more concerned about how good the end result is.
I will repeat it again because I missed making direct reference to Float when quoting Caletka and much can be lost with this omission, sorry.
Float is a relative value. It determines which activities are more critical than others. The precise numerical value is not as important as the absolute delay calculated when measuring the planned completion date to the projected completion date. From, Delay Analysis in Construction Contracts P. J. Keane & A. F. Caletka
Calling on a recommended practice to display float values and continuous critical longest path is wrong if the software you call by first name (P3) and last name (Primavera) is incapable of displaying continuous longest path when some activities are driven by resource availability.
A recommended practice that works only in the absence of resource leveling is wrong.
Best regards,
Rafael
Hello Rafael,
1) I think that most of them, might be actually busy with some San Francisco Conference that is in like 4 days or so?
You can register and use the AACEi forum without being a member and there are no costs for using the forum.
Use this link:
http://www.aacei.org/cgi-bin/forums/board-profile.cgi?action=register
Just a single note. While I might agree that bias is not a good thing, but the fact that some institutions such as the GSA has been requiring Primavera in their specifications or COC is definitely not illegal. Remember that according to the law, there is a freedom of contract. The two parties are free to agree on whatever they want as long as its not murder, prostitution etc.. you got the point.
The only legal argument i can see , is that this behaviour might qualify as being against US antitrust laws. But to prove that, you have to prove that the GSA is actually choosing PRimavera cause it has a vested interest (agreement, getting paid, etc..) to promote primavera and no other functional reason to do so. I personally do not think that is the case. But feel free to prove otherwise.
2)
Again Longest Path Concept wasn't created by Primavera or one of its Employees.
The reason I keep repeating that, is because, while I agree that there is a problem , I don't quite agree on the description i.e that the Longest Path itself is flawed. I find it rather more adequate to describe the problem by either stating that "Primavera's implementation" of the Longest Path is flawed or more correctly (at least I think so) "Primavera's Resource Leveling Algorithm is flawed" and affects the Longest Path. I think you agree , since we have both been, a while ago, in discussions with Vladimir and others where the flawed resource leveling algorithms of many softwares were thoroughly discussed.
I agree with you on the negative float issue. That is my perspective as well.
3)
Thank you for the file . I'll download and run. What other Planning Software are you using and what results is it giving you?
I have openPlan i'll try with that as well.
4) Your constant usage of screen snapshots, is always very helpful. I thought I'd let you know :)
Best Regards,
Roland
Ronald,
1) I used the following e-mail addresses as could not find other general e-mail address, I am not copying the full e-mail address to respect the privacy of the individuals although at the AACE site you can get their full e-mail address
'Kieshia.Cobb@xxxx' and to 'pbredeho@xxxx'
To post into AAEP forums you got to be a member, membership is not for free is at a cost.
I do not believe AACE behaved in a professional manner by making biased references to Primavera Software, I believe it wrong and do not deserve much respect, they got what they deserve, it is irresponsible and disrespectful to users of other software. I believe they have serious economic interests in Primavera products and on other supporting software they or their members sell.
For years I have seen the American bias toward Primavera Products, even have seen Primavera products being brand name specified by some of our institutions like the GSA "General Service Administration", this is against the law and believe even against international treaties that promote free commerce, at some point such wrong behavior get you angry. That it shows, yes.
2) I believe the Critical Path can be a discontinuous set, same as any mathematical answer can be.
The problem with the AACE 29R-03 is that it requires a continuous path in its protocol when under resource leveling it can be discontinuous, this requirement is wrong.
For example go to page 18 and under B. Recommended Protocol you will find: Ensure that there is at least one continuous critical path, using the longest path criterion that starts at the earliest occurring schedule activity in the network (start milestone) and ends at the latest occurring schedule activity in the network (finish milestone).
It is not a scandal Longest Path breaks, asking for it to be no-breaking is.
3) AACE RP-03 is biased towards Primavera Products because they are requiring Longest Path Functionality as per their own definition, unneeded functionality in their protocol that is available in all Primavera products and in software supplied by a software vendor that is part of the team that wrote the practice but not available in all software as it is flawed. To make it worse this functionality is useless and misleading under resource leveling. That longest path functionality is flawed goes beyond Primavera products it is enough resource leveling to make it flawed.
AACE RP-03 is biased towards Primavera Products because they are requiring Negative Float Functionality, unneeded functionality to prove cause and effect, that is not impelemented in all software as it is flawed. This functionality we all know hides project logic and there are better ways to deal with the issue on criticality of intermediate milestones.
This functionality is implemented by Primavera products but not all products use it, other use better implementation on the functionality of finish constraints. By requiring its use in the case the other party uses the concept they rule out other software that purposedly avoid it, is subtle and is on purpose. The creation of negative float disrupts the cumulative curves to an "impossible" representation, that it is a mathematical result does not justify wrong modeling. With negative float the cumulative S curves can intersect at some point before finish date, is modeling of the impossible. Negative float is flawed functionality, there is no need to force others to use flawed logic.
4) You can download the schedule from the following link.
https://rapidshare.com/files/460405961/LPTH.PRX
Excuse any misspelling it was so easy to figure out it was developed on the fly.
The following Pert Diagram can help you reconstruct the sample job in case the backup file does not works.
Best regards,
Rafael
PS. If you do a search in my posting for "flawed" there is a possibility you will get as much hits as if you search for P3 on the AACE 29R-03 document, maybe we are even.
Hello Rafael,
1 ) Which email address did you use to send your complaint to the AACEi?(i bet its info@aacei...)
If you haven't received an answer so far, this doesn't necessarily mean , as Mike has tried to suggest, they do not wish to answer. I suggest you post your complaint on the AACEi forums as well. Of course, need not say, that you'd voice your concern in a constructive manner. The removal of words such as "joke", "ridiculous" and so on, might actually help you get your point through in a more professional manner.
You'd be surprised that a lot of people might agree to some of the points you've raised or that you'd actually get a clarification concerning your query/complaint.
And no, AACEi's ivory tower is not too high in the clouds.
2) I was striken by a statement you made. If you care to clarify as I might have misunderstood.
In your original message, you state and I quote:
"If because of different calendars or resource leveling the critical path is discontinuous then let it be, just keep the correct mathematical meaning of float."
but then you go on, maybe rightfully (as I didn't have time to do the exercise) , to note how the "Longest Path" will not provide a continuous path, as it should, in some circumstances.
Would you care to elaborate why do you consider that when the Critical Path , defined using the TF=Value formula, breaks, we should let it be? while if the Critical Path, defined using the Longest Path formula as implemented by Primavera, breaks in then it's a Scandal?
That doesn't sound right to me.
3) Most importantly, why are you assuming that RP 29R-03 is biased towards Primavera Software and the Primavera implementation of the Longest Path , as you call it.
As far as I can remember, the Longest Path concept was not developed by Primavera or a Primavera Employee. Just because Primavera has a Longest Path Implementation, it doesn't mean they own the Concept.
The point is:
It seems that you are making an assumption that RP 29R-03 is based on Primavera and therefore that its mention of "Longest Path" must definitely mean Primavera's own implementation of the Longest Path and thus RP 29R-03 is flawed because you know for certain that Primavera's implementation of the "Longest Path" breaks for resource critical networks.
Maybe if you try to think that when RP 29R-03 mentions the "Longest Path", it is not being Primavera Specific, thus doesn't suffer from the fallbacks of the Primavera Implementation, and might therefore not be as flawed as you might have thought.
4) In the schedule attached to your earlier message, have you actually linked the activities with FS relations? I want to try to duplicate your schedule with the same settings/rules/logic and so on.
Best Regards,
Roland Tannous
Hi Rafael
I doubt if you will get a constructive response from anyone at AACE - their ivory tower is too high in the clouds.
The SCL protocol is similarly flawed - mainly because they have not updated the text to follow the latest law cases.
Keep up your crusade - I am following it with interest.
To use the Ostrich analogy "If you have your head in the sand - your butt is in the air" - prime target for a good kicking.
Best regards
Mike T.
This morning I emailed to AACE International about my compalint on AACE being flawed and biased. No answer from AACE International yet but will keep you informed. Anyone wanting to openly debate the issue is welcomed.
As you can see from the above model P3 cannot identify Longest Path under resource leveling, therefore a protocol or delay analysis practice that depends on flawed longest path theory is also flawed.