One of the biggest challenges with building project schedules is that often you don’t know the details of a piece of work but you need it on your schedule regardless.
Yes, you know you need to say remediate an area once you’ve installed the watermain underground. But early in the project, the finer details of what that remediation might look like are scarce.
Enter Rolling Wave Planning.
If you work in IT or software development, everyone knows about Rolling Wave Planning. It’s the foundation of iterative methodologies like SCRUM or Lean.
But maybe you didn’t know we can also apply it to construction projects.
What is Rolling Wave Planning?
Rolling Wave planning is a planning technique that involves elaborating more detail in your schedule as more information is available, or as you get nearer to the execution of the work. The idea is to plan in waves and clarify assumptions and approach as the execution of that a piece of work gets nearer.
At the onset of a project, we won’t know everything about late work at a detailed level, but we will have a general idea of about the work. Not only that, everything on a construction project may change quickly.
The concept of progressive elaboration applies to rolling wave planning, as you will continuously refine, add detail and clear up assumptions to constantly evolve your project schedule.
Often times, a project using rolling wave will clearly outline a planning schedule for elaborating a plan.
For example, the team might agree on 7 months prior to work execution, to have a level 5 detailed plan in place. The schedule will contain a level 3 or level 4 detail leading up to that point.
Here’s how AACEi defines Rolling Wave planning in their document 23R-02: Identification of Activities:
We all apply some sort of progressive elaboration when we build schedules. But with Rolling Wave planning, you make that elaborating into a more formalized approach with a timeline for adding detail.
What’s wrong with using Rolling Wave Planning in Primavera P6?
Well, as with any helpful technique, it can be abused or ill-used.
In general, leaning on the technique of Rolling Wave planning that I will show you shouldn’t become an excuse for building detailed schedules as soon as possible.
The sooner you can define the details of a construction project, plan them in Primavera P6 and schedule them, the less risk you have in the execution of that construction project.
I fully advise you to build a fully detailed level 5 schedule as soon as you have all of the information required to do so.
Not sure how to build proper level 5 schedules in Primavera P6? Learn how with the BEST online training on Primavera P6.
Of course, sometimes you are not going to know the details of a piece of work. In that case, you can use place holder activities at level 3 or level 4 in Primavera P6 to capture and hold a space for the work.
Here’s a example of that in Primavera P6:
Lastly, you’ll see above that AACE recommends that Rolling Wave Planning be used only on “longterm complex ventures”. I’ve seen this replaced elsewhere with the term “programs” or a very large multi-year undertakings.
This wording is meant to discourage the use and abuse of Rolling Wave on typical construction or oil & gas projects.
To try to get some further insight on using Rolling Wave, I asked around the www.aacei.org forums for opinions and guidance from other practioners.
The responses varied from “use with caution” to “you have what you need to build a detailed schedule if you look hard enough” to “use in the right context”. All of this is sound advice.
Now I think Rolling Wave can solve an important problem if used properly, and in the right situation as well. So please take these points into consideration as you explore this technique.
Rolling Wave Planning in Primavera P6
I’m going to show you the steps to elaborate level 3 or 4 activities with a series of detailed activities in Primavera P6. This process can be used for Rolling Wave Planning in Primavera P6 projects.
If you’d rather watch a video of how to implement my Rolling Wave Planning in Primavera P6 approach, scroll down to the video below.
The setup for Rolling Wave Planning in Primavera P6
First off, let me explain that in my example you’ll see the following setup:
1. My project has a Baseline
This is important to note and a key part of this technique relies on not removing activities from the project that are in the baseline. We keep all activities in the current project. We also add more detailed activities.
That way we can continue to compare our place holder activities to their counterparts in the baseline.
2. Place holder Activities can be on the critical path.
This isn’t a problem either. I will show you that we can add the detailed activities to the critical path, replacing the place holder activity.
3. WBS level remains the same.
One of the pitfalls of P6 is that you cannot convert an Activity into a WBS element. In this process of progressive elaboration, being able to take a long-duration Activity and converting it into a WBS element would be really handy.
But we don’t have that feature.
So I’m leaving my activities within the same WBS level in this rolling wave planning technique.
The place holder activity in Primavera P6 will become a summary Level of Effort Activity and additional detailed Activities will be added at the same level.
Let me show you Rolling Wave planning in Primavera P6 step by step.
Step 1 – Adding Detailed Activities to Elaborate Your Placeholder
Let’s first add the detailed Activities for our placeholder Activity – Fabricate Wheelshop Equipment.
Here they are with Durations.
Now let’s fix the Activity IDs so they align with RMF-PROC-2260. There’s not much to see after that.
Step 2 – Linking The Detailed Activities
Next, let’s link all of these 6 Activities together with FS relationships.
Now, let’s dig into the predecessors & successors for Fabricate Wheel Shop.
I next want to assign the same predecessor shown above to Activity “1 Fabricate Stands”.
I want to assign the successor shown Activity here to “6 Test Wheel Shop Equipment”.
I’ll then reschedule and you’ll see that my detailed Activities fragnet now falls into the right timeline for dates.
That’s looking much better.
Step 3 – Setup Linking for Level of Effort
This is where the magic happens.
Ultimately, I could remove the placeholder.
But then I won’t be able to compare where I planned this work to my baseline.
So I’m going to turn the placeholder into a summary Level of Effort activity.
To do that, I need to put in place the links for a Level of Effort that tell it what to summarize.
I’ll assign it 2 new successors:
- 1 Fabricate Stands – Start-to-Start
- 6 Test Wheel Shop Equipment – Finish-to-Finish
Step 4 – Convert Your Placeholder to a Level of Effort
The last step is to change the Activity Type on Fabricate Wheel Shop Equipment to a Level of Effort. Then reschedule the project in P6.
Here’s the result of our Rolling Wave planning technique in Primavera P6.
Note that the project’s Critical Path now no longer includes the placeholder Activity as it did originally. The Critical Path now passes through the detailed Activities, as it should.
Also have a look at our new summary activity.
Did you notice that the total duration changed to 247 days?
That’s because Fabricate Wheel Shop Equipment now summarizes the activities below it and their total Duration is 247 days taking Calendars into account.
It will also expand if the work goes lates or contract if the work finishes early.
And we can continue to compare to the original baseline dates.
Watch the Video of Rolling Wave Planning in Primavera P6
You can use the Rolling Wave planning in Primavera P6 technique above to help you progressively elaborate a project schedule, either as you get more detailed information about the work or as you get nearer to the execution of the work.
Again, I think the best part of this approach is that your project continues to be in comparison with the baseline.