Activity on Arrow and Non-Continuous PDM are wrong.

Hi Rafael,

As you know it, you can tweak or cheat with the program (GIGO). I supposed these algorithms don’t have the capabilities to lie.

Oh by the way, with the four (4) activities only the third and fourth activities moved when I run/level the schedule, the first and second remained in place and displayed no resource in the spreadsheet (but they were assigned as well).

Best regards

Anoon,

Of course you can tweak or cheat with the program, especially when the tool is no longer a management tool but a tool to be used as a claim tool.

Some Contractors here create a CPM that should favor their claims and use it just for these purposes and manage the job using "experience", I call it "perception" a concept management schools and behaviorist scientist study as it can be deceiving. Others, I would say the majority, create two versions, one that hides float to the Owner and favors his claims and another that represents his dynamic planning. Is a well known secret.

Best regards,
Rafael

Hi Rafael,

I don’t understand about strategies or how do you present your schedules. I’m just a scheduler (or just a follower for the good side - and it doesn’t include cheating).

Going back to float calculations or results after resource levelling, for now I would say that what you were saying about P6 is not true, but that’s understandable as you were just exagerating and not really trying it yourself (so I can forgive you with that). And please note, the version I used is 6.1 (not the latest one), and further note that the trial is just limited to 4 activities. So again, beyond that, I don’t know.

I just hope that someday you will really try it yourself and may we hear your expert and honest opinion about it (without the sales talk).

Best regards

p.s. Sorry, I suspect that the results of your sample or your sample was inflicted by not so logical - logic.

Anoon,

Sorry but here cheating is a fact of life, we even have criminals, this is no Disney World.

Many of us find it unfair when the Owner steals away from you your own planning tool and even go further to steal away available float from your own planning as we perceive float as a buffer necessary to avoid delaying your job, if stolen from you then it will no longer be available. The truth is some designers are a disaster and must issue hundreds of revisions to their drawings, and then they delay the job and pretend the Contractor to pay for their error. Under these circumstances we find it morally acceptable and even good business practice from the Contractors point of view to hide some float. Imagine when the software shows available float and it does not exists, some Owners will even try to steal from you unavailable float, is insane.

The wrong computations for float is a fact in Primavera SureTack, in Primavera P3 as well as in MS Project. We observed P6 float calculations were wrong as I told you but cannot recall the version because I never paid attention to it, it could have been 6.0. In any case because of the file sent to me I suspect newer versions of P6 are still displaying some wrong values for float. I was not exaggerating, in any case software developers that display wrong float values and with the knowledge this is so do not warn the user are cheating their own clients.

On the displayed Screen Capture all logic is shown, there are two resources and only two FS links. Is necessary for you to include the links as shown and resource usage as shown, otherwise the model is other.

I do not believe I will ever buy a P6 license but perhaps will be able to try it again on the computer of someone with the license.

Let’s see if I can get a copy of the file so I can make it available for the use of all by posting it on Rapidshare.

Best regards,
Rafael

Hi Rafael,

Yes I can see it, but it seems that the logic is discontinuous (i.e. 2nd and third activity has no relationship). I guess the erroneous floats were caused by erroneous logics. Please try to connect them all with FS only or SS only and see the results.

As we are considering resource dependencies, logic must be established by the shared resource or resources, which means that settings shall be all focused on the shared resource or resources.

You can forget the logic that you had established for your activities.

This is what I’m trying to asked on Vladimir in previous or other threads:

What is most important, Activity logic or Resource Logic?

And he said both, but he is defining Activities or Tasks first (in terms of logic).

So in case of conflicts, which logic governs during resource levelling?

Best regards

Anoon,

-“What is most important, Activity logic or Resource Logic?”

Both are relevant, both must be taken into consideration.

Remember the sample job is just an example but you can add a Start event and a Finish event as for you not to leave any open end but only at the start event and finish event.

Why are you to model a logic link between two activities when there is no logic link, this prevents the model to be a good representation of the network as the resource dependencies are not fixed and can vary as the schedule moves. This unreal links are known as "soft links" and are even banned by some of our CPM specs, the same specs that require you to use resource loading with a software of their choosing incapable of displaying true available Float after resource leveling, perhaps with the intention to steal away from you not only available float but unavailable float as well.

By the way, thanks for your honesty about what is displaying your model. If does not agree with my statement it shall be disclosed, PP is about exposing the truth for the benefit of all members.

Best regards,
Rafael

Rafael,

Yes, I stand by my statement. For P6 (6.1), what you said is not true. For P3, from my trial, yes you are right.

Best regards

Hi Anoon,
please clarify what is not true?
Best Regards,
Vladimir

Anoon and all I got the sample P6 file in xer format so any of you with P6 can work it out please download from the following link.

http://rapidshare.com/files/375131764/Example.xer

Anoon,

I just realized that the prior example sent to me is in disagreement because it was set up to work under optimization an automatic resource leveling option that consistently yields shorter job duration in Spider, I was comparing apples with oranges. The following is a screen capture of the resource leveling results using the previous sample job using Spider optimization.



I am using another example of the small project where all activities are linked only with Finish milestone. The float of activity 2 (ID:A1010) is rather strange. Please next after you will find the computations of float that Spider yields, these are the correct values.





Sorry for any inconveniences, at times determining where some software will display wrong values for float is not easy for me when I do not have the software. The P6 files were issued on the run with the help of someone not in my office, this is making it harder to prove the point but does not invalidate it.

Best regards,
Rafael

Hi Vladimir,

To clarify the statement of Rafael that P6 displays wrong float(s) (whatever it is Free Float or Total float) after resource levelling - That is not true (at least from my own trials).

Hi Rafael,

You are not making real comparisons. I guess you are just finding faults, but please be fair. You need to put the two programs in exactly the same settings and options (if that is possible) and run the schedule or resource levelling, so that we shall know which one is a copy of what?

Oh by the way, I don’t know if P6 has the capability to show Resource Bars.

Best regards

hi all

that’s far what I got from experimenting in Primavera p6.
as far as you put only activities with one resources and without links, P6 handle well, and it give you the right Total float, but if you start with only four activities, and assigning two resources and some links, it level correctly the activities (max usage not reached) but you will get inaccurate total float, sometimes even some negative one.

notice here, i did not change any default rule

i hope i am wrong in my calculations, but it is a a very serious matter, we call this bug, or even worst, defective by design.

best regards

Mimoune

Hi Mimoune,

I suspect that you are the one who supplied Rafael with that sample?

"notice here, i did not change any default rule"

As you had mentioned, of course this will create some discrepancy as you are supposed to handle "resource levelling".

In my opinion, your settings and options are supposed to be tailored to handle resource levelling as well.

How can you level Resources if your activities were set to "Task Dependent"? I supposed your program will follow task dependencies and not resource dependencies.

Now, I guess Vladimir and Rafael is saying that Spider can handle both dependencies (Task and Resource), at the same time when levelling resources, but I’m not really sure if which one governs (or they did not tell us) when making adjustments in order to get the minimum duration possible?

Best regards

Hi Anoon,
please clarify what may be changed with the schedule and floats if to select task or resource dependent and all activities and resources have the same calendars.
I did not try to say anything about Spider but of course all restrictions shall be taken into account during scheduling (levelling) process. No one restriction governs - all shall be satisfied.
I did not understand if you tried Rafael example or not?
Resource levelling does not require tailoring - it shall create the project schedule based on the same data and satisfying all resource limitations. Besides the shortest resource constrained schedule means better resource utilization.

Best Regards,
Vladimir

I would like to highlight that in occasions, especially with simple jobs, Standard resource leveling algorithm in Spider is still Optimal. Standard resource leveling algorithm in Spider yields similar result to other software.

I agree with Vladimir that resource leveling should look for minimum job duration, if not you can level your resource using Rafael Algorithm, is very simple just set all activities in tandem, only one activity happening on a given time and here you got a feasible solution with regard to the issue of resource availability.

For your convenience I uploaded in Rapidshare the xer file for the second sample job, if interested you can download it from the following link.

http://rapidshare.com/files/375350976/Test.xer

I have read some literature in search of Resource Critical Path, some do not mention the need for resource leveling on the backward pass while other papers by Vladimir Liberzon mention the need. Is possible that P6 algorithm is based on other methodology and this is why some results are wrong pretending they are right, who knows.

No matter what we must be critical and do as Anoon, question it until we make it clear.

That mimoune got it on the spot does not means he supplied me with the sample job, I believe he mentioned other occasions P6 yields strange results for float, he noticed the behavior in real life jobs and not only in particular sample jobs, he knew about this way before the issue was raised on this thread.

Best regards,
Rafael

HI Anoon

i hope you are kidding me, there is no conspiracy here, i have no affiliation with Rafael, but i do have an advantage, which is i am a junior, it means, i don’t have any strong idea about any method, i am just learning, I don’t care really if P6 is better or not comparing to others packages. but i do care to have a correct results.

yes, as A P3 user, i set many rules for priority of resource leveling, it depends, total float, early start, etc, sometimes i just fellow the intuition of the construction manager, he wants to put more resources on a particular task, after all he is the responsible not me.

having saying that, and from a guy who is aware, there is no exact solutions for the problems of resource leveling, but rather many approach to solve the problem and give a good solution to satisfy both resource availability and logic constraints. all those rules are for getting better solution, let’s say optimizing the solutions. but no matter what you have set as rules the result must be correct.


i expect from the software to give me a correct solution, perhaps far from optimum, but nevertheless correct (it satisfy the conditions), otherwise it is an issue and should be declared by the vendor.

and for testing the four activities schedule, no need to check another package, manual calculation, can spot, that there is something not ok.

best regards
Mimoune

Dear All,

Sorry if I cannot really answer well all your clarifications as I was just fired (anyway, no worries, I’m used to it).

As regards using exactly the same calendars for activities and resource, well I never said that, but I supposed there would be no problem with resource levelling if this is the case.

The problem I believed will occur (with resource levelling) is when using different or various calendars for activities and resources.

How can you make a coordinated resource levelling when using various calendars? For me, this is impossible, but I’m not sure of course (as my mind is just ordinary).

And I’m really curious about Vladimir’s and Rafael’s solution to this, which up to now, all I hear is something better than sales talk.

Best regards

pfffff sorry Anoon to hear that, anyway what are you doing in Philippine anyway !

Just to prove that i am really open mind, i think i was wrong, actually P6, give correct values for resource leveling including total float, but there is a hick.

in the case of a simple schedule ( 4 activities) P6, give a solutions which is so far from the optimum solutions, that automatically a normal joe will conclude it is wrong. but in reality( mathematical meaning) it is a correct solution in the sens that it satisfy the conditions( both links and resource availability)but unfortunately it increase project duration.

best regards
Mimoune

The value of float for activity A1010 displayed by P6 is wrong under the prioritization rules that set up the sequence of the resource leveled schedule. Under this sequence if you delay the finish of this activity by 10 days it will occur at the same time with activity A1030, this means P6 is not in compliance with the requirement for the algorithm to respect constraints, is breaking the premise that no matter what you have set as rules the result must be correct



Note that under resource leveling the real float bar cannot always be considered continuous, you can delay the activity to happen at the late bar position and satisfy the resource constraint requirements but not necessarily if in between, this means there are also limitations on whether you can increase the duration or not of the activity.

Best regards,
Rafael

Hi Mimoune,

Actually, right now, I’m near your country.

Anyway, I supposed the intention is to do "resource levelling" so as to get the minimum duration possible.

This is considering that you will be using resource calendars as well as activities calendars which are not necessarily the same or consistent.

And I guess Vladimir is offering a solution, why not try it Mimoune?

Hi Rafael,

I believe that you cannot prove it with just your presentation below and you did not elaborate with the parameters that you had used (or used by someone else).

Best regards

Anoon,

You can download the sample file from the following link.

http://rapidshare.com/files/375350976/Test.xer

Even if you cannot figure it out about the parameters chosen it is enough proof if only a single activity displays wrong value of float. Also review my posting #120 were the occurrence is pointed out.

You can also go back at Spider float values as per my posting no 111. They are different therefore either one must be wrong. Well it is P6 who is wrong as a simple analysis of the figure shown in posting #120 proves it, P6 is displaying wrong float for activity A1010, is quite simple.

Best regards,
Rafael

All,

To resolve the issues regarding float calculation after resource levelling I downloaded the test xer from Rafael.

This is what I found out. Primavera is calculating the same result as shown from the screen shot shown by Rafael done in Spider Project after a few experiment.(note: we are not comparing software to software here. It is just an experiment what bugs Primavera have when levelling a resource.)

The screen shot from Rafael using Primavera showing wrong float is because the units allocated for Task 2 is exceeding from the max units set on the R2 which is 8hrs/day. On screen shot below it shows 13.33hrs/day having 40hrs/3days. (note: hrs or unit is used to represent unit/duration). In this case Primavera will not touch or calculate Task 2 because levelling in P6 doesn’t extend duration that is why it will remain at it is.


After changing labor units assign to Task 2 (8hrs/day * 3 = 24) I run resource levelling again and below is the result. Total float = 2 which is the same as Rafael Screen shot from Spider. (note: This experiment is limited only on the sample provided and haven’t test on unlimited activities)


Another issue that I found out is “Hours Per Time Period” (Users Preference-> Time Units tab) is used to calculate for total working hours per day and use the calendar as limit of time per working hours. See below by changing 8 working hours to 12 working hours the total float change from 2 to 1.


I also test using different activity type between Resource Dependent and Task Dependent and it has no effect if using same calendar. See below using Resource Dependent Activity Type with 8hrs – 5 days working calendar and 8 hrs working hour’s cycle set on Hours Per Time Period.

Conclusion: Based on the sample xer provided, P6 stands as calculating correctly when levelling resource.

See comparison below using same labor unit/ resource loading as showed on the profile




Note: This is conducted to resolve the issue and not to harm anybody.
Platform use for testing: P6.1

Dear Rodel,
please explain why
1) P6 does not warn about resource overload when resource is assigned 13h/day and calculated resource-constrained schedule?
2) the float is larger when resource requirements are higher?
I am intrigued by these results and want to play with P6 myself. I suspect that 13 hours/day may appear automatically if to shorten activity duration from 5 to 3 without reassigning resources, isn’t it? Very strange setting.

Spider Project would warn that you need additional units of resource R2 and will refuse to level the project.

Please explain.

Best Regards,
Vladimir

Vladimir,
P6 actually warned that resource is overloaded. (see below) You’re correct that the cause of 13.33hr/d is due to duration change. The behaviour of P6 is depends on the settings. The user can control Primavera’s behaviour on settings available.


On this exercise Duration type is set to Fixed Duration & Unit meaning Unit/Time is variable but if the setting is Fixed Duration and Unit/Time or Fixed Unit/Time then the unit will automatically change and become variable.

Best Regards,
Rodel

Rodel,
I will see this warning only looking to the specific resource histogram. In the projects with hundreds resources assigned it is impossible to check the histograms of all resources.
I still don’t understand why the float become larger for overallocated resource.
I would expect that the package will warn that the levelling is impossible without adding additional resources to resource pool because the quantity of resources assigned to the single activity exceeds available quantity. I think that it is logical.

Actually I don’t approve assigning hours without assigning quantities. In this case it is not possible to assign two resource units with 50% workload if the quantity is not specified.

Best Regards,
Vladimir

Vladimir,
I agree with you that P6 will not physically prompt the user if the resource is overloaded. The user needs to check the histogram or unit/time to know the reason why? I figure it out when I overload all resources and P6 done nothing. It did not level resource and everything is the same. Like what you said every package have differences and I think this one is missing in P6 (prompting the user why it is not levelling). The fastest way to check the error is by reading the log file when selected Log to file option. It mentions which activity cannot be levelled.

In regards to 50% assignment as I mention on other post (using multiple calendar), P6 responded based on calendar and hours per time period settings.
If you need 50% per resource then calendar must set on each resource. (ex: R1[a]=8:00AM-12:PM and R1[b]=12:00PM-04:00PM) within 8hrs setting at hour per time period.

Best Regards,
Rodel

I did not mean that resource has less work hours.
The requirements on the work do not utilize the whole work time of the resource and the resource is able to do some other works in parallel.
It is necessary to define both quantities and workloads of assigned resources.
Best Regards,
Vladimir

Rodel and Vladimir,

If you move activity A1010 to the late bar location as determined by the 10 days total float shown in the example R2 will be over-allocated then this by definition is not resource constraining and the value as shown is misleading and is wrong, I would call it limited resource over-allocation as to distinguish it from true resource allocation. Does this mean P6 is incapable of performing true resource constraining? Is there a way to make P6 to display correct float value for activity A1010 that satisfy the requirement for the resources no to be over-allocated? What value of float for activity A1010 will P6 show if true resource constraining that does not allow for over-allocation is performed by P6, of course assuming P6 can perform true resource constraining?

What is the practical value of a functionality that does not solve the issue for over-allocation? How can you say a mathematical model supposed to solve the issue on resource availability allows over-allocation to happen is mathematically correct? In any case the values shown shall be named “over-allocated resources float” as not to mix it with the true definition of resource critical float and shall be shown on under a different field while the correct value for resource float shall still be shown under the total float field.

If P6 is going to provide over-allocated float under the same column other correct values are shown then at least shall provide an indicator of where this is happening. In such case I still prefer to show 2 columns, one with the correct value and another with a value that allows over-allocation though I do not know if the last value is useful.

If float can be anything you want then why show it, why use the term in CPM specifications? Better keep it simple float is always 0.

Best regards,
Rafael

Vladimir,
I know what do you mean but this is not included on this exercise. We only comparing apple to apple as per example. Maybe we can demonstrate another problem illustrating this issue using same comparison again. I’m happy to know what bugs really reside on P6 so all users/planner become aware.

Rafael,
I used only same comparison with the sample that you illustrate. As I said (if you read my post) P6 did not touch or did not levelled Task 2 for having over allocated loading which is indicated on the log file. (A1010 not level using forward, A1010 not level using backward). On the figure comparison (apple to apple) using same resource loading it show exactly the same including resource histogram.

I suggest that if possible try overloading resource on Task 2 and let us know what will be the result. It’s very interesting to know if your tool will come up different result.

Best Regards,
Rodel

Rodel,

I do not know how to force Spider Project to allow for over allocation under a functionality that shall work. Resource constraining in Spider Project always respect the mathematical requirements for the model to schedule within available resources. Either it will tell you it is impossible, not uncommon within material resources, a functionality I believe is possible P6 does not have or it will delay project completion respecting the validity of the resource constraining algorithm, otherwise it should be called resource over-allocation, something that does not solve the issue and that should not be allowed by any CPM specification.

Is kind of similar to when there is an out-of-sequence occurrence, the only way to solve it is by fixing logic, not by an automated procedure that pretends to solve it as if a universally correct procedure. Over-allocations must be solved by making available more resources, by allowing the schedule to slip, yes that the job is projected to be late can be a true model projection, or by any other appropriate mean. Leaving over-allocations unsolved is wrong and should not be allowed.

If your software artificially constraint project end date you will not be able to see the logic within your schedule, you got to let the software to show the delay and from here you start making the adjustments.

Do your specs allow for resource overallocation happen without being cleared?

Best regards,
Rafael

Rafael,

I believed P6 is the same not leveling over allocated resource. Maybe the only difference is Spider Project prompt the user that cannot level due to over allocated while P6 prompt the user by the way of log file.
As I mention earlier, I figure it out when I over allocated all resources and P6 did nothing. When I check the log file it mention not leveled for every activity having over allocated resource.

Rodel,

I am not sure about P6, but for years before using SureTrak we used P3. P3 had the option to select for resource leveling not to allow the leveling routine to extend project duration and stop applying true resource constraining to these resources or you could select for resource constraining routine to respect resource requirement and allow the software to show true schedule projection.

As we all know some settings that allow you to bypass schedule logic are considered “bad practice”. Allowing the software to level some resources and others not is bad practice, it hides logic, and it hides the fact that if some resource issues are not solved then the schedule due date will not be met. If the software cannot provide you with true resource constrained float then the problem becomes even greater.

Spider is not like P6 it will not perform the leveling routine allowing over-allocation of course if need be it will delay project completion and then it is the responsibility of the scheduler to work it out. It will correctly display over-allocations before running the resource leveling routine. If resource leveling is impossible like if you have an acitivity asking for more of the available for the resource it will delay the activity and warn you that the resource leveling missing the requirement.

Best regards,
Rafael

Rafael,

As I said, P6 is doing the same thing. Many options have been removed from P3 to P6 like extending or shorten duration when leveling. I’m not sure if the planner/user is aware of what P3 or P6 response to leveling when they are not reading the result log file. It’s all there what has been leveled, errors & warning, exclusion, number of activities leveled, number of activities wrong sequence or in correct logic etc… I believed most of the user just leveled and never read the report. I always check the report that is why I know what’s happening during the level, schedule, export, import etc...

I suggest all planner/ user to use/ read the log file to check what error or warnings indicated on the log file after executing application to understand what happened after the execution.

Best Regards,
Rodel

Rodel,

Here the schedule report is to be submitted with every schedule update and all out-of-sequence as well all resource issues are required to be solved, is a contractual requirement. We are not allowed to submit a schedule that hold the projected finish date by allowing over-allocation, we must either take the steps to get on target or report true projections by allowing the software to show how much off target we are.

I am not sure how this is enforced for jobs where P6 is required, but won’t be surprised if P6 dictates what others shall do as long as many continue with the infatuation with Primavera Products.

Best regards,
Rafael

Rafael,
Sorry, I’m not sure what you want to portrait.
Again, if the planner/ user read the log file he will understand all information for error, warning, exclusion, out of sequence, not leveled, schedule override… etc…
As you said, it is the responsibility of the planner to correct all those findings. So what’s the problem there?

Best Regards,
Rodel

THE PROBLEM IS THAT FLOAT AS DISPLAYED BY P6 AFTER RESOURCE LEVELING IS PLAIN WRONG.

As long as float is mentioned in the specs the required software shall be one that shows the correct math.

Definition of float requires it to meet all logic and resource constraints. Showing incorrect float values for resource leveled jobs is wrong. If not available without delaying the job duration in compliance with resource requirements shall not be shown by pretending it is correct.

Best regards,
Rafael

Rafael,
We respect what you believed. We know that we cannot change what you insist and that your own opinion. We just proved based on your example that your claimed is wrong. It will not change until it’s proven. We love to know all the bugs we can encounter using P6 to be aware and not to compare. I am not defending P6 here. I just want to resolve the issue by doing the exercise as you requested for other to enlighten what is the result.
Best Regards,
Rodel

Rodel,

My example shows two computations of float for activity A1010, P6 says it is 10 days which does not makes any sense, if you delay the activity to late bar either over-allocation will happen or the job will be delayed, this breaks the basic rules of resource constraining. On the other hand Spider Project shows 2 days float, the correct value.

Does P6 displays a warning that for activity A1010 the displayed value of float will over-allocate the resource? I doubt it and would like to see such a report.

Best regards,
Rafael

Rafael,

We just prove why and spider project don’t do it either because it over allocated which is the same as P6 clearly prompted on the log file.

We do the exercise fair and compare apple to apple as per your sample.

If you don’t want to open your eyes, it’s up to you and we respect it. As for the P6 users we still stand P6 have the same result and correctly leveled the resource.

Best Regards,
Rodel

Rodel,

I am now using the post # 139 but the issue here concerning resource leveling is not yet reconciled. Maybe you guys can utilize more all your efforts in other threads.

For me, I’m going to defend Primavera and P6 since this is the mostly-used and industry required software in Middle East. Otherwise, will be out of jobs. I wish we’ll have the chance to use the full version of Spider.

I would love to see Vladimir marketing the software in the Middle East.

Best regards,
R. Catalan

Rafael & Rodel,

Cool down guys, you’ve overtaken me in taking post #139.

Hey Rafael, have you subscribe to Mayweather vs Mosley fight this May 1? I’m very excited to see this fight. The same with Cotto vs Foreman.

Best regards,
R. Catalan

Catalan,

Usually I subscribe for the fights the very same day directly through the cable box, and this fight I am not going to miss. Cotto fight might be on HBO and in such case it will be for free, this one also I am not to miss.

Rodel,

As you can see we are tolerant to change direction in the discussion, if you look at the title it was supposed to bring controversy in another theme I was hoping to be even more controversial.

Anoon, Catalan, Mike Testro and the others at times calm us down with unexpected comments I love and appreciate.

Best Regards,
Rafael

R. Catalan,
I’m cooled as the weather here in Melbourne is starting too breezed... and don’t mean for any fight.
I respect Rafael’s opinion but we stand P6 is correct.

Rafael,
Below is the report as requested.
Scheduling/Leveling Report - 15-Apr-10 12:09 AM - PM.exe
========================================================

Default Project..................................................Test

Projects:
Test............................................................Test For Resource Leveling

Scheduling/Leveling Settings:
-----------------------------
General
-------
Scheduling ......................................................Yes
Leveling ........................................................Yes
Ignore relationships to and from other projects .................Yes
Make open-ended activities critical .............................No
Use Expected Finish Dates .......................................Yes
Schedule automatically when a change affects dates ..............No
Level resources during scheduling ...............................No
Recalculate assignment costs after scheduling ...................No
When scheduling progressed activities use .......................Progress Override
Calculate start-to-start lag from ...............................Actual Start
Define critical activities as Total Float less than or equal to .0
Compute Total Float As ..........................................Start Float
Calendar for scheduling Relationship Lag ........................Predecessor Activity Calendar
Preserve scheduled early and late dates..........................No
Level resources only within activity Total Float.................No
Level Priority 1.................................................Activity Leveling Priority - Ascending
Level all resources..............................................Yes

Advanced
--------
Calculate multiple float paths...................................Yes
Calculate multiple float paths using.............................Total Float
Number of paths to calculate.....................................5

Statistics:
-----------
# Projects.......................................................1
# Activities.....................................................5
# Not Started....................................................5
# In Progress....................................................0
# Completed......................................................0
# Relationships..................................................3
# Activities with Constraint.....................................0

Errors:
-------
Warnings:
---------
Activities without predecessors..................................4
Project: Test Activity: A1000 1
Project: Test Activity: A1010 2
Project: Test Activity: A1020 3
Project: Test Activity: A1030 4

Activities without successors....................................2
Project: Test Activity: A1010 2
Project: Test Activity: A1040 5

Out-of-sequence activities.......................................0

Activities with Actual Dates > Data Date.........................0

Milestone Activities with invalid relationships..................0

Scheduling/Leveling Results:
----------------------------
# Projects Scheduled/Leveled.....................................1
# Activities Scheduled/Leveled...................................5
Data Date........................................................05-Apr-10 12:00 AM
Earliest Early Start Date........................................05-Apr-10 08:00 AM
Latest Early Finish Date.........................................17-Apr-10 05:00 PM
Number of float paths............................................0
Exceptions:
-----------
Critical Activities..............................................4
Project: Test Activity: A1000 1
Project: Test Activity: A1020 3
Project: Test Activity: A1030 4
Project: Test Activity: A1040 5

Activities with unsatisfied constraints..........................0

Activities with unsatisfied relationships........................0

Activities with external dates...................................0

Activities delayed due to predecessor delay......................1
Project: Test Activity: A1040 5

Activities delayed due to resource leveling......................2
Project: Test Activity: A1020 3
Project: Test Activity: A1030 4

Activities that cannot be leveled................................1
Project: Test Activity: A1010 2

Activities that cannot be leveled backward.......................1
Project: Test Activity: A1010 2

Activities that are not on any float paths.......................4
Project: Test Activity: A1010 2
Project: Test Activity: A1020 3
Project: Test Activity: A1030 4
Project: Test Activity: A1040 5

Rodel,

I cannot understand some of the settings as they are particular to P6, one that I do not understand is the setting for relationship lag calendar:

Calendar for scheduling Relationship Lag ........................Predecessor Activity Calendar

I must assume there is the option to define an individual calendar for every relationship. For example in some links the lag can be set by work days calendar while in other occasions it got to be modeled using calendar days even when successor and predecessor calendars are in work days. Take for example bonding agent and cement plaster, if during a week end the lag between the two shall be modeled as per a different calendar used by both activities. I thought this was available on P6.

Also cannot understand use Expected Finish date as in Primavera SureTrak Expected Finish Dates is not a constraint per se but a subroutine that re-compute remaining durations.

About Progress Override is a setting banned in our specs.

About Compute Total Float As Start Float, does it means you can redefine float and get different results? Total float cannot be both, there shall be a standard. I heard of other software that go as far as allowing you to add a third definition, the maximum of Start and Finish float, it can be anything you want it to be.

I cannot not see a warning telling that the displayed value of float for activity A1010 will delay the job completion or will result in an over-allocation.

I cannot understand “Activity that cannot be leveled A1010”.

Perhaps with this you will understand how unfair it is to force a Contractor to use scheduling software other than his own.

Best regards,
Rafael

Rafael,
You can read PMRefMan if you need to understand your entire question as it will cover all the pages here in PP. Its self explanatory and I use default option when running resource leveling.

Ex: “Calendar for scheduling Relationship Lag ........................Predecessor Activity Calendar”
It is an option where most of Planning Software now is using to calculate relationship lag. The default on MS Project 98 to 2002 version, P3 and others planning software is Predecessor Activity Calendar. In P6 you can select as shown on my post link below.
.xer to .prx Post #6

Cannot leveled means not leveling that particuar activity (Forward, Backward) Please refer to the manual link below.
Primavera 6.1 Reference Manual

Best Regards,
Rodel

Seriously

please this is a very simple question for every body.

if a software after leveling ( respecting maximum availability of resources and network logic) say that an activity has for example 15 days of total float.
what does that suppose to mean !?

best regards

mimoune

This is supposed to mean that if activity is delayed to occur at late bar it will not be overloaded.

Note that there might be instances between early bar and late bar the activity cannot be rescheduled without overloading, this is a trap with resource constraining we must be aware.

Vladimir,

Plase correct me if I am wrong.

I know at times it is needed to model volume lag but I am keeping the issue out as not to camplicate modeling of lag any further.

Rodel,

Do you mean P6 lag cannot have its own calendar, that got to be either predecessor or successor calendar across the board. In occasions I have the need to model lag using a different calendar than predecessor or successor and in other occasions when successor and predecessor calendars are different my model requires for it in some instances to be successor and in other to be predecessor.

At times we use a calendar for lag different from successor and predecessor activities such as when specs require for you to wait a specific time duration for backfilling, less if concrete cores yield a certain strength, while at times the minimum stripping time is to prevent concrete creep so time can have precedence even when strength is achieved, we model lag using the appropriate calendar.

There are other occasions where this happens but the illustration is from a draft schedule of a job that is about to start.



Best regards,
Rafael

Rafael thanks

please i need a simple answer

did the total float shown by spider project, respect those conditions ( resource max usage, and network logic)for all the duration of the said float.

Best regards
Mimoune

mimoune,

Because it is just 2 days float in this case yes. This sample job cannot illustrate my second statement that you cannot always place at will the activity somewhere in between the late bar and early bar without it becoming in conflict with availability of resources. There got to be available idle resources for your bar relocation(s).

I am working on a quantity take off for a bid but tomorrow will try to create a sample job to illustrate my second statement in a way you can manually move the bar in between early and late bar and resource availability is not there.

Best regards,
Rafael

Hi Mimoune,
I think that this question is to me.
Spider Project calculates forward and backward resource constrained schedules and the float shows maximal delay of activity start (or finish) that does not delay project finish.
It does not mean that intermediate delays are acceptable.
Spider Project also calculates resource assignment floats and there are examples that activity is critical (its start cannot be delayed) but has finish float (the work is done by another shift).

You may notice that Spider Project shows early and late bars for activity dates and not the lines for activity floats.

Best Regards,
Vladimir