Hi Ramesh / Vlad,

Andrew Dick has written a fantastic paper on Resource allocatin in P3. Check his previous post in the same thread.

Good explanation of Rolling Wave Planning & Planning Packages (Control Accounts)

You can request him for the papers.

Cheers,

Raviraj A Bhedase

Hi Vlad,

Thanks. I am glad that you understood my point of view very
well. I couldnt agree more with you on the point of risk
simulations and adding contingency reserves. One clear
example of that could be seemingly unreasonable durations
for certain activities. But when it comes to practical
execution at site, we could realise that the durations
were not actually unreasonable, in fact, they prove to
be just enough. The hard part in such cases is to convince
the Engineer and Client of such time frames because they
would normally relate the required time frame straightaway
with the associated quantities. But the fact is that when
the schedule is at a higher level, we have to disassociate,
for many cases, the estimated quantum of work from the
estimate of time required, incorporate our risk factors &
contingencies and then arrive at the final estimate.

Now, when the breaking down of these levels is done, we
may find that adjustments may be required. Now the problem
here is that we would have already submitted this higher
level base to the Engineer/Client, who then go strictly by
that.

I personally feel that the best solution for all this would
be to go for bottom-up planning rather than top-down planning as
then we could have everything in detail which could be rolled
up at any higher levels required. Because, in Top-down approach,
this discrepancy in methodology is bound to surface when we do
further detailing. Whereas, in Bottom-up, the detailing is
already done and can be rolled up which saves all the time
of further creation of Rolling waves.

But then, as you rightly put Vlad, this could be very time
consuming and moreover, it requires much deeper insight and
study of large projects right from the beginning which no
one is ready for, all the pressure is usually on the planner
to know everything, or at least, most of the things.
So, probably the only good thing for planners would be to get
more than the 28 days allowed as per Contract conditions to
prepare the initial Baseline, at least for large projects
which span for 2 to 3 years....:-).
Lets say, maybe a formula based determination like 5% of the
duration of the project in days or 28 days, whichever is higher..:-).

Happy Planning folks....

Ramesh

Thanks Raviraj,

Would like to clarify that when I said horizontal I wanted
to emphasise on the fact that as opposed to vertical
construction like high rise, the sequence of overall
construction in such plants is not straight forward or
rigid. For example, in high rise or any building, one
has to go floor by floor one after the previous in a
continuous fashion. Whereas, in such plant constructions,
there could many possibilities of unit sequence assuming
of course, that the complete possession of SITE is
available. If there is sequential handover of SITE from
client, then at least that would govern the construction
sequence by contractor. Otherwise, options are many. Then,
I would imagine, it would be more governed by unit equipment
deliveries and furthermore, cash flow profile. Though of
course, Civil works would still have lots of flexibility
assuming there arent many resource constraints.

However, its possible that having adopted such an approach,
it still could lead to quite a few changes in actual
construction as units which havent been planned will have
to be approached for construction as delays in planned
units due to design issues, approval issues, could happen.
(Here I particularly mean such reasons of delay which are
outside the controls of the Contractor)
This could then lead to resource imbalance if resources
are very tightly planned and are not ample. How do we
then tackle the situation in such cases ? Could this be
a case for a claim of any sort, time or money ?

All the above could reflect as a disagreement between the
main higher level programme prepared first for submission
and the rolling wave that occurs at current situation. How
do we tackle this ?

Vlad, could you also please share your view on this ?

Cheers & Regards,

Ramesh

I would agree Raviraj. We could go on to any level of
detailing in our schedules but of course we wouldnt want
to give the Engineer or Client details to that extent. I
dont think it would be necessary too as such a level of
detailing would be for internal work front estalishments
and detailed resource planning. The higher levels with
flexibilities incorporated should be for Cl.14 monitoring.

Vlad, that was a nice example of the rolling wave technique
applied to high rise. However, in case of horizontal wide-
area projects like process plants, it is very difficult
to establish fragnets repeatedly as each process unit could
be unique and completely different from the others. This
would involve detailed study of every unit, individual
unique method statements of construction, thereby leading
to detailed scheduling. Such a level, would in any case be
difficult to achieve in the initial submissions. How do we
then establish the sufficient level of detailing in such
cases ?

Happy Planning folks.....

Ramesh

For me, as Dieter said, it is a very commonly practiced technique.

Its only now (May be few years before), that we have given name to this methodology of working. Its there in PMBOK too.

Cheers,

Raviraj

Yes, I described the technique that is easy with the use of the software.
The manual scheduling is hard in any case. But in this case too it is reasonable to create predefined fragnets and add them to the schedule when necessary.

I will suggest an example:
for the nearest 4 floors each floor will consist of external walls, internal walls, columns, staircases, brick works, floors work packages.
Internal wall work package will consist of Reinforcement, formworks installation, concreting, curing and framework striking. Other work packages will be decribed in similar details with assigned resources, materials, costs.
Starting with the 5th floor from the current floors will be presented as activities linked by Start-Start dependency with the lag. The lag size is based on the detailed schedule results. Materials and costs are assigned to the floor. After current floor will be finished 5th floor will replaced by the small project (we call it typical fragnet) that describes floor construction in details (as described above).

Hi Guys,

I did encounter rolling waves techniques.

Vlad,

The theory behind Rolling waves is great.

In my experience as project management consultant, the rolling waves degenirated into just plain three months look-ahead schedule filtered from primavera DD+3M. Also to that effect, the planning and control did not make any difference.

The contractor find it hard to reconcile what is happening at site compared to his plans: rolling plans (wave) three months.

Vlad, I thank you for your enlightenment. I will ensure rolling waves techniques will be implemented and monitored in all project I manage, starting today base on your concept.

Hi Andrew,

I’m glad if you share your ideas, please sent me a copy: charlieorbe@gmail.com.

Cheersa and I thank you in advance.

Joseph

Hi Raja!
Rolling wave means that you have the detailed schedule for the nearest period and not that detailed for the rest of the project. This period shall be defined in advance and kept during the project. If for an example you decided that the period for detailed planning shall be 3 months then you shall always have the detailed schedule for 3 months ahead of you. If 1st month is behind then the detailed schedule includes 4th month.
In high rise construction we found through work simulation that deviations in the schedule influence the schedules of the next three floors, on the 4th floor the difference is almost absent. So we decided that there is a need for the detailed schedule for the next 4 floors and after that it is enough to schedule floors as activities.
Hi Andrew!
Thank you for the suggestion. I would like to read your paper though we use different software.
My E-mail: spider@mail.cnt.ru
Vladimir

Hi Vlad,
Long time didnt meet your post thread, Anyway could you brief me little bit about this technique... Maybe its the same with mine but different definition, interms of words.

p.s.Try to figure out... is it like wave. ha ha
nothing offended just lefted behind by technology.