Rolling Wave Scheduling

Hi Patrick

You can google the topic just as easily as I can.

The main point about rolling wave planning is that the planner has a good guess at how long each section of work at level 3 will take - dont even think about trying it at level 2.

Then when it comes to starting the section he either develops a detailed programme at level 4 or 5 or imports a subcontractor's programme and links up.

The detailed Level 4 programme never matches the best guess at Level 3 so you have a constantly evolving contract programme - with a constantly shifting end date.

Another problem is that at Level 3 you can only use SS links with some estimated Lead Lags but at Level 4 you should be using only FS links.

So how do you link up to the Downstream sections?

Another best guess combined with all the others.

You may discover some good points in your research but they will most certainly be promoted by lazy planners.

I always suggest using bottom up planning starting at Level 5 tasks and summarising upwards to level 1 - planners say that this takes too long and is too complex and I say NO.

I am currently working on a 42 storey hotel on a 7 level basement podium it will take me approximately 40 hours to complete the fully resourced programme using Asata PowerProject software.

There will be no guesswork on the duration and no task will be longer than 12 days duration.

Best regards

Mie Testro

Mike,

it is easy to create the detailed model for high rise construction but is it really necessary?

In similar project we created the detailed model for concreting works and simulated some delays. As the result the schedule and floor construction duration was changed at the next 4 floors but starting with 5th duration of the floor construction and the order of work did not change.

So we decided to implement detailed 5th level (?) schedule for five floors and leave third level schedule (6th floor, 7th floor, etc.) for the rest of the building. Yes, these floors were linked by SS and FF links with the lags calculated in the detailed schedule, so what if these links represent the reality?

After current floor was finished, 6th floor construction activity was replaced by its detailed schedule, etc. It worked perfectly. For Spider Project it does not matter much if the schedule consists of 2 or 20 thousands activities but for some packages it may several times increase the speed of calculations, and some (like MS Project) do not work properly with large project models.

But mostly we use rolling wave when we have not sufficient information on future jobs.

It is usual when design is created in parallel with construction and at project start we have sufficient information for detailed planning only for the nearest part of the works. So we have no choice except application of rolling wave planning.

Best Regards,

Vladimir

Thanks Mike,

I have done some research on google but you would be surprised on how little i have found so far. Thanks for the help.

Hi Vladimir

In a high rise concrete structure the level 5 detail is obvious and easy to copy for each level.

It is also possible to set up curing periods in calendar days on lead links for release of forms and clearance of back propping - thus giving precise start dates for following trades.

On the 42 storey project that I mentioned I was asked to accelerate completion by double shift operations.

On level 5 I could pinpont the trade resources that would create the required result - structure and cladding.

I could not have done this on a level 3 summary programe.

That is one reason why I advocate bottom up planning.

Best regards

Mike Testro

Hi Pat

Try putting Rolling Wave in the PP search box - 4 or 5 pages of threads on the topic.

Best regards

Mike Testro

Thanks for this information...