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Engineer’s Review of the submitted Initial CPM

26 replies [Last post]
Mon, 2010-03-15 01:56
Samer Zawaydeh
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Dear All,

This is the Title of Chapter 28 in "CPM in Construction Management" 7e, by James J. O’brien and Fredric L. PLotnick.

The last few lines in the last paragraph in this chapter go link this:

"Finally, the engineer should "walk through the CPM" and determine if everything "smells right", possibly leading to additional scruting. But the review of the initial submittal of the CPM must be handled in as professional a manner as any other submittal to the engineer."

And that is what the undersign emphasis clearly on any project. I wanted to share this because it is important to know.

If anybody would like to add someone thing, it would be good to hear.

With kind regards,

Samer
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Replies

Fri, 2010-03-19 07:26
#1
Samer Zawaydeh
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Dear Anoon,

The following site has information that you might find useful. It has white papers as well that you can download.

Plenty of ideas and useful information. I think that you will enjoy reading the problem solving techniques.

http://www.mindtools.com/pages/main/newMN_TED.htm - 96k

With kind regards,

Samer

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Thu, 2010-03-18 15:23
#2
Samer Zawaydeh
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Dear Anoon,

When you have an EPC contract, the Design is not ready. But Contractually, you need to complete a deliverable.

Usually, the EPC contractors will have a database with similar projects, and they can commit to the delivery with a degree of certainty.

It depends on the situation, but logically, you start with an acceptable Milestone Schedule accompanied with the actual details for the next few months. This will be further developed when the design phase is complete.

With kind regards,

Samer
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Thu, 2010-03-18 08:54
#3
Anoon Iimos
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Hi Samer,

What can happen? Your sponsoring my tour of Jordan? Well, thank you very much (I just hope Mike and others will not envy me)...I guess for the oldies, the future is now (I’m still young by the way).

Yes, how can you schedule something you do not know?

So do you mean now that the "Initial CPM" can be derived from the Level one schedule?

Or ideally, from which level of schedule the so-called "Initial CPM" or critical path can be derived from?

Is there a specific level of schedule (i.e from level 3 or 4), that you could say, that the "Critical Path" of the project derived from, is somehow realistic or attainable?; which shall represent a statistical percentage or number of activities, against total number of activities of the schedule?

Regards
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Thu, 2010-03-18 07:53
#4
Samer Zawaydeh
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Dear Anoon,

I hope that it can happen in the future in good time.

You can only Schedule what you know! If you have an EPC contract (I think that this is what you mean when you say you do not have a BOQ at the Start), then you start with LEVEL 1 program of works (approved at least internally) and you move on with your Engineering Design and further development of the Program of Works.

Decision Making is a statistical process. I receommend that you google it and you will find out that the basic building blocks of Decision making are statistics and probabilities theories.

I will try to find something good for you to read.

With kind regards,

Samer
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Thu, 2010-03-18 07:47
#5
Ernesto Montales
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My view is keep the post coming... it may be rubbish for others but I say not to all.. It gives up an open minded kind of approach.. People does have different points of view and that what make us unique!!!

Happy Planning guys!!!!

Regards,

Ernesto
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Thu, 2010-03-18 07:11
#6
Mike Testro
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Hi Anoon

Probably not as much rubbish as I put out every week.

Best regards

Mike Testro.
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Thu, 2010-03-18 05:54
#7
Anoon Iimos
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Hi Mike,

May I ask you, out of 1,000 posts, how much percentage do you think is rubbish?

If you say more than 50%, then I would stop posting anymore.

Regards
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Thu, 2010-03-18 05:03
#8
Mike Testro
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Hi Anoon

Congratulations on your 1000 posts.

Best regards

Mike Testro
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Thu, 2010-03-18 03:47
#9
Anoon Iimos
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Hi Samer,

Oh, sorry I don’t know that, Thanks, I don’t have any plans of coming over to Jordan, but if you’ll sponsor me (I mean including all expenses), why not? We’re 5 in the family by the way (got a wife and three kids), and I’m not really choosy with the hotels you know..for as long as it’s cozy and safe...

1. Not all Projects have BOQs in the first place. How to develop BOQ, given the general scope of works or concept?

3. Statistics I guessed are random, so it can be anything.

8. How do you apply statistics in decision making? considering feelings or emotions, likes and dislikes etc...

Regards

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Wed, 2010-03-17 07:45
#10
Samer Zawaydeh
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Dear Anoon,

You gave me a good laugh. I am Roman Catholic :) Keep in mind that Jordan was named after the River Jordan, and Jesus was baptized in the River Jordan 2010 years ago. If you come over, I will take you to the Baptizm place, they have 6 churches and they are building one more now. Jordan is a Muslim Country with 2-3% Christians.

1. Rule of thumb: So if you have a BOQ with 50 tables you sum up the number if items in each BOQ and you get a minimum number of 1 activity per deliverable. Good start.

3. The author referred to statistical analysis Anoon, so maybe if you sum up the Program of works that you have and try to determine the number of critical activities in each approved program of works, you can write the first chapter in your book.

8. This has to do with common sense. Although I have read in the past that the number of women Project Managers in the north of Europe is higher than the number of men. I know for a fact that upper management with sensitive decision making try to keep a balanced percentage.

With kind regards,

Samer
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Wed, 2010-03-17 07:28
#11
Anoon Iimos
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Dear PP Addicts,

1. The rule of thumb: I remember one thread here "Number of Activities" - I don’t know if they came up with a conclusion?

For me, at least one (1) activity to represent a certain deliverable (regardless of the price).

2. Relationships: Like husband and wife - only one (for catholics); but if one is having an affair then maybe "1.6" is acceptable. I guess Samer can have four?

3. Percentage of Critical Activites: I don’t know anything about this, please go on with your discussions.

8. Feelings?: What does feelings got to do with the Schedule? Maybe the woman is the better Scheduler?
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Wed, 2010-03-17 06:58
#12
Samer Zawaydeh
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Dear Mike,

I can’t comment on the auther’s recommendations. That is relative to his/ experience. I just summarized what was in the book and wanted to share the key information that was relative to me as well.

1. The Rule of thumb: I know that is not relative, but it can give ideas to LEVEL 1 schedules.

2. The relationship issue: This might be a statistical summary that the author did on his project.

3. The % of critical actiivties: This is also a relative thing. Maybe they are setting a rule to accept at the project at the start of the works. Seems a high percentage for me at the start of work.

8. I think that they wanted to keep the human element in the equation. The fact is; experience is key. If an experience manager reviews the Schedule and says that it is wrong, this is enough for the Scheduler to go back to the drawing boards. This is acceptable to me.

With kind regards,

Samer
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Wed, 2010-03-17 06:08
#13
Mike Testro
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Hi Samer

I have to comment on some of these points:

1. Rule of thumb is a minimum of one activity for each $10,000 of Contract Value.
So a $100k project only has 10 tasks?

2. A healthy network should have at least 1.6 relationships per activity.
In a FS bottom up chart the ratio is 1:1

3. If the number of critical activities (on the longest path) is near or exceeds 25%, additional scrutiny mabe be called for.
This implies that more than 25% critical is a bad thing - I see no substantiation for such an assertion.

6. Check EVERY constraint.
And then remove them.

8. The Engineer must "FEEL" that enough contingency has been included in the Schedule.
Feelings are not good enough - contingency has to be expressed within the programme.

Best regards

Mike Testro.

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Wed, 2010-03-17 05:23
#14
Samer Zawaydeh
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Dear Anoon,

I held for 24 hours ;), now it is time to continue the discussion.

Here are the major pointers in the same Chapeter:

1. Rule of thumb is a minimum of one activity for each $10,000 of Contract Value.

2. A healthy network should have at least 1.6 relationships per activity.

3. If the number of critical activities (on the longest path) is near or exceeds 25%, additional scrutiny mabe be called for.

4. Near Critical Activities (5-10 days float) should be also reviewed.

5. The initial submittal: nothing started, nothing finished, and zero percent complete.

6. Check EVERY constraint.

7. The larger the durations and the more complex the project, the lower the probability that the project will be completed on time.

8. The Engineer must "FEEL" that enough contingency has been included in the Schedule.

9. The Engineer must "Walk through" the critical path and the near critical path to make sure that the logic makes sense.

10. Duration should be reasonable and internally consistent.

11. Before rejection, DISCUSS questions with the Contractor.

12. After checking the duration and logic, THEN the Engineer can walk through the printable bar charts.

13. If something is out of order, send an inquiry.

14. Multiple Calenders; you need to check the software files.

15. Educate the users of the Program of Works.

With kind regards,

Samer
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Tue, 2010-03-16 09:21
#15
Anoon Iimos
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Hi Samer,

Excuse me Scarllet...(would you mind if you hold Samer?)

These are what I meant for the following:

1. Identifying - Determine the activities / tasks covering the full scope of works - this cannot be done by a software.

2. Defining - Define logical relationships of the activities or tasks so that you’ll get the minimum time (Duration) possible for the executions.

2.1 This shall include what I said the "added details" like "resources". Again, define resources (I mean here labor / tools / equipment,- to be calculated against permanent materials or installations) so that you’ll get the minimum time or duration possible.

Again, I believe that this cannot be done by a software, but it can assist.

3. Quantifying - Well, you define the duration(s) (again, defining), assign to activity(s), run the software - The software will give you the spread (total) and the floats easily.

So where is the Critical Path evolved from?

cheers
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Tue, 2010-03-16 08:20
#16
Scarllet Pimpernel
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Hi Samer,

In your reply #8, you quote some Recommended Practice from AACEI.

Is this the intenct of the Author of the book, that the Engineer must be expert in accordance to AACEI RP.

I can say, there are few Engineers fully conversant much less knowegeable in AACEI RP.

The Author maybe imagining superman in the Engineer.

I think the review is not realistic, it exist only in the imagination of the Author that somehow the Engineer may do this and that. It practically emphasize that the Engineer is a roboot to the author idea.

IMHO,

Thank you,
Scarlett
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Tue, 2010-03-16 03:00
#17
Samer Zawaydeh
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Dear Anoon,

Two answers:

1. You have different levels of Schedules. You start with Level 1: Milestone schedule and you can go up to Level 5: Daily or hourly Schedule.

2. The way that you construct a Schedule in P6, ASTA or MSP, etc is using the CPM. The CPM construction is done in the following steps; identifying activities, resources, duration, sequence, relationships and constraints, the the software will calculate the forward pass and the backword pass, and identify the activities with ZERO FLOAT. The path along the ZERO FLOAT activities is called the Critical Path.

I hope by "Quantifying" you mean the resources and durations, and by "Details" you mean the sequence and relationships. Because there is nothing more than that.

With kind regards,

Samer
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Tue, 2010-03-16 02:35
#18
Anoon Iimos
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Hi Samer,

I may define Critical Path as the result of identifying, quantifying, defining details and adding more details.... The more you got details. the more it becomes complicated, therefore you need the software to do the calculations.

Software has the algorithm, but it can never identify, and define, it may only quantify.

Do you mean the Critical Path Method is only a result of the quantifications?

Regards
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Tue, 2010-03-16 01:57
#19
Samer Zawaydeh
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Dear Chandana,

I think if you have "Matured Engineers" on your site, then you need to trust what they are saying, not what the software is telling you :)

The biggest success factory on the job, is the experience of the team. I am not sure about the size, type and complexity of the job that you are talking about. But the software is a tool only. It will not complete the job of hundreds of people completing thousands of manhours.

If you are worried about something and you want to convince your team that the software is showing something is wrong, then I suggest that you try more than one approach. Your Program should have successfully predicated and is still predicting the actual end dates of activities. This can only happen if the "Matured Engineers" gave you what they know at the planning stage.

If your problem is showing them the Lead and Lags, then print it out or let them review the soft copy with you.

With kind regards,

Samer
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Tue, 2010-03-16 01:44
#20
Samer Zawaydeh
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Dear Anoon,

Answer 1: This is officially answered in the Cost Engineering Terminology issued by the AACE International Recommended Practice No 10S-90.

Answer 2: The critical path is a result of the components; Activities, Durations, Resources, Relationship, and lately we came to understand that it deffers depending on the software that you are using. So it is a software programming dependent. It should not be, because the theory is the same. But with the vast array of options and complications, it become dependent. You can have a look at the AACE 49R-06 "Identifying the Critical Path" that was published this March 2010 :) and have a published source of information about the subject.

With kind regards,

Samer
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Tue, 2010-03-16 01:20
#21
Anoon Iimos
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All,

Questions:

1. What’s the difference between "Critical Path Method" and "Critical Path Analysis"?

2. What are the parameters or criteria for reviewing the Critical Path?


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Mon, 2010-03-15 19:31
#22
Chandana V
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Hi Samer,

It is true software determine the Critical path given that your logic & relationships are right and properly assigned.

When it comes to review, How do we ensure/check the above. Most of the matured engineers are not comfortable with softwares.

The only way I know is add columns for relationships in gantchart view. But in P6 it is quite hard as it does not show the Lead/lag time assigned for particular relationship.

Is there way out of this or How do we enable hard copy review for the guys who do not use softwares.

Thanksin advance.

Ch

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Mon, 2010-03-15 15:57
#23
Samer Zawaydeh
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Dear Anoon,

The terminology CPM is associated with a software. This is software dependent.

An experienced Engineer can do "determination". They have to power (depending on the Form of Contract) to recommend for EOT. If this is a simple job, then this can be easily determined.

You can walk around site, and determine what is needed to be done to complete the project. If you are smart enough, work fast enough, and continuously planning you activities and engaging you team in the daily planning, I would confidently say that you do not need a software. Experience coupled with superior site managment will take care of all critical paths on a daily basis.

"Practical Analysis" is not a term that can determined practically. You need to be able to support your activities are site with the proper documents to make the analysis. What do you propose to have as "INPUT" for "Practical Analysis" Anoon. I am very interested to know that.

Experienced site people "feel" what is wrong at site because they have done that and they have been their. I can confidently tell you that you can complete a project successfully without a critical path. And I can confidently tell you that you will not be able to prove your entitlement without proper supporting documents. In absence of a Schedule, what do you propose will be the basis to determine that a Critical Path was delayed?

With kind regards,

Samer
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Mon, 2010-03-15 09:29
#24
Anoon Iimos
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Hi Samer,

Please clarify your statement:

"and then your software will determine the Critical Path."

Is this usually the case? I mean the current practice or recommended practice?

So the Engineer always need a software (or must know how to use one)in order for him / her to properly review or evaluate the critical path?

Or an experienced Engineer who doesn’t know how to use the software (but able to plan) will not be qualified to review the "critical path" (Current situation)?

Is there any other basis, aside from float, to determine what is the critical activity? I mean for the sake of practical analysis.

Thank you
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Mon, 2010-03-15 02:38
#25
Anoon Iimos
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Hi Samer,

The "Engineer" here means...? Client’s engineer, Designer, Client’s Rep., Client’s Project Manager or Contractor’s Project Manager? I supposed all of them shall play the major role(s) in reviewing CPM.

Initial CPM might be derived from the general scope of works (contract), but how about the Contractor’s Methodology?

Isn’t the real CPM will come from the Contractor’s Methodology?

Regards
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Mon, 2010-03-15 05:35
#26
Samer Zawaydeh
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Dear Anoon,

The Engineer means the party (Consulting Firm) that is appointed by the Owner to administer the Contract.

The second part of your question is about: Contractor’s Methodology. The Contractor is the one who determines how they are going to execute the works. No doubt about it. The Engineer perform the review and provide any comments (if any).

This is directly related to the Form of Contract that you are using. FIDIC for example, specify the time a Program of Work should be submitted. It does not specify what is the level of detail, etc.

You make the plan, make sure that everything that you want to deliver is included in the plan, then you start the Scheduling. You make the list of actvities, duration, resources, relationship, and then your software will determine the Critical Path.

With kind regards,

Samer
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