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I am making a case for "non-related sequential logic"not physical related but the logic is not everything can get done at once.

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John Reeves
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I am making a case for "sequential logic" - not physical related but the logic is not everything can get done at once.  Is this a know practice - or am I now making it one.  Your thoughts - I have commonly done this but not named it as such.  I really dislike a schedule that has 50 submittals all starting the same day with tons of float, I like to stagger the start, but these crazy restrictive specs means that I have to tie them logically when "logically" there is no tie but sequentially there is.  Did I just create the term "non related sequential logic"? Is there a better term for this?

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Rafael Davila
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David Kelly
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Santosh,

The term I would use for the concept of placing logic into tasks that isn't based on any physical requirements but is purely discretionary, is "wrong". In my not very humble opinion, relationships between activities should depend on the laws of physics, nothing else.

Vladimir,

"Splitting" is not a term used in P6. In the last ten years I have helped about 50 clients to implement P6, and often support them through deploymnent.Only one uses leveling. The two major reasons are lack of control over splitting, and the lag in FS relationships is always "minimum" and cannot be mandatory.

Hi Santosh,

I understood that such soft logic is not permitted by specs.

Resource leveling is easy workaround and is better because the number of activities that can be done in parallel depends on resource availability.

Santosh Bhat
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John isn't asking for a method of how to resequence, he's simply suggesting a term for the concept of placing logic into tasks that isn't based on any physical requirements but is purely discretionary.

Hi David,

in Spider Project if an activity can be splitted is activty property.

Is it possible to permit or to ban activity splitting in P6?

Rafael Davila
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We define workload as the percentage of time a resource is uniformly distributed throughout team execution.  If less than 100% we call it partial workload, others call it part-time. Sharing of some resources on part time basis is an everyday issue no scheduler or project manager can overlook.

  • A classic example would be a tower crane, it is shared by many activities in parallel but there is a limit on how much work it can do on a sigle day, such assignment must be leveled to make sure the schedule is feasible. This is the case where a single resource is shared on a part time basis among many activities.
  • Another example can be resource assignments on a design office where same designers work on several jobs at the same time.  Because some interaction with the client is necessary it makes no sense to assign all resources one job at a time. This is a case where many resources are shared on part time basis.

To assign resources to work part-time on several activities on the same day happens every day in most construction jobs. With partial workload functionality there is no need to split the activities, just make partial workload assigments, so easy, so common, it is elemantary resource management.

Image-004

In the above schedule the handling of Submittals by GC can start at the same time before resource leveling.  After resource leveling Resource A works on the same day on different activities, never more than the available 8 hours per day, the resource leveling engine will delay some activities if need be as not to overload the resource.  Splitting of activities for such simple task is not a good idea, with hundreds of submittals manual leveling is nuts.

David Kelly
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What Zoltan and Vladimir say.

Resource levelling is the easiest way to control priorities, it is a simple change in the value of the field used to allocate priority for resources.

HOWEVER you have to be careful in P6. It does not offer proper control over interrupting an activity that has started and doing another one of higher priority – we used to call it “splitting” in the last century when Primavera software had some element of control for this.

Zoltan Palffy
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one way to get fix the all submittals starting at the same time is if you tie a resource to them and let the availabliity of the resource drive whne they can be submitted.

Rafael Davila
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It is wrong for General Contractor to forward some submittals without any review on his part.  Most construction contracts state that the General Contractor is responsible to make sure submitted materials and equipment do fit.  I have seen materials and equipment specified that do not fits on the space provided. You might argue it is a design error, but you signed a contract that says it is your responsibility to make sure it fits, under the contract terms you are being paid to make this check.

As suggested before make sure you allocate the necessary resources to perform these tasks.

Rafael Davila
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  • ARTIFICIALLY DELAYING THE START OF WORK BY OTHERS CAN BACKFIRE: Why prevent them to submit as early as they can?  If you tell a supplier the submittal can wait he will wait and use the time to the benefit of other jobs. On the other hand not taking into consideration your limits on how many submittals you can review and forward for designer review is also wrong.
  • Place the delays where they belong; it is your handling of the submittals where the bottleneck can be as this requires some effort on your part. So you might have many submittals deliveries by your suppliers with same early start date but your work on each might have different early start as you cannot process them all at the same time. I would keep these activities separate as they are to be performed by different resources you must manage using realistic resource effort, realistic production rates and activity durations.
  • Consider adding an activity for your handling and forwarding of the submittals. Resource load these activities with your best estimate of duration and make sure workload yields estimated effort.
  • Be reminded that a review can take several days as it might depend on the feedback of others/outsiders. So the reviewer will work only a fraction of the day on this review to give it time for others to answer his questions, this is called partial workload. For simple reviews that do not require the feedback of others/outsiders consider 100% workload with short duration. The idea on resource loading and leveling is on assisting you to create/update good feasible schedules.
  • There is much logic in handling resource constraints, it is just the correct mathematical algorithms are different.
  • When you are not responsible for the designer review of submittals usually the contract specifies a duration that is responsibility of other party and who must make sure he has the resources to deliver within the allotted time.  Unfortunately many times such promise is broken.

Submittalsjpg-Page1

Johannes Vandenberg
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Hi John,

Vladimir has the suggested the best option. Resource loading the schedule and leveling or smoothing. Here is an example how this works.

Santosh Bhat
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John, its often referred to as "Soft-logic", but if you're interested in finding out more, look into RDCPM:

RDCPM®, the Relationship Diagramming Method (RDM) variation of the Critical Path Method of schedule analysis focuses on the reason for the relationship between activities and the reason for their overlap1 . It is distinguished from the Precedence version of CPM (PDM) developed by Dr. John Fondahl in 19612 by the inclusion of significant additional information. 

Source: Microsoft Word - WP1035_RD-CPM (mosaicprojects.com.au)

If you will create some resource and assign it to all submissions that shall be modeled as activities with some duration, and then run resource leveling for resource created and assigned, your submittals will become sequential automatically.

The sequence can be managed by applying activity priorities.

I don't think that any spec bans resource leveling.