Month: December 2017

Construction Scheduling. Too much Detail.

When we develop the Baseline CPM Schedule for a construction project, we need to develop the WBS to establish the project deliverables.

To what level of detail is this required?

The general idea is to decompose the project deliverable down to the Work Package level. For construction, this could be taking the WBS down to an area of structural foundation for a large project. It is really taking the deliverable down to the point that it can be easily identified and measured.

We then develop the “work” activities that need to happen to produce this deliverable.

Basically, we develop the list of activities, sequence them, assign the resource(s) and determine the Activity Duration, and assign the activity’s Budgeted Cost. There are also the Activity Code, Calendar, and Role assignments…

Many specifications have limits on the number of Work or Calendar Day duration a “work” activity may be assigned. A good rule of thumb is “not to exceed the reporting period”. I like to cap my “work” activities at 20 Work Days or less. An activity should only have one responsible party performing the work. If an activity only has one party performing the work and the duration of the work is going to exceed 20 Work Days, perhaps it is best to break the work area down to allow smaller durations. It is difficult to accurately measure the performance of activities with large areas or durations.

The use of activities with large Activity Durations also leads to the use of Start-to-Start and/or Finish-to-Finish relationships to model the work which is now running concurrently with other large duration activities. This should be limited. The overuse of Start-to-Start and/or Finish-to Finish relationships is a basic problem for many detailed project schedules. Makes a pretty Gantt Chart, but does not allow adequate control and measurement of scheduled work.

Most deliverables should have activities with durations much less than 20 Work Days. They should not all be 1 Work Day unless that is actually what it takes to model the work of several parties. Usually, the “work” could be broken down to 5 days to excavate the foundation, 2 days to install reinforcing steel and any vapor barrier or blockouts, and 1 day to place concrete and an activity with a period of time for concrete curing. Breaking the work down to this level allows the work to be easily measured and managed. Too often I see a “Place Foundation Concrete” activity with a duration of 10 Work Days. No cure activity. No idea if cure time is included or not…. No idea when the excavation should complete or when the reinforcement placement starts…. Most likely, the formwork and reinforcement work will run concurrently at some point and the concrete placement will be driven by the finish of the reinforcement work and inspection. If there is a delay in delivery of reinforcement steel, we should be able to accurately model that…..

The idea is to develop a schedule which is manageable and has enough detail to control the work. Pretty simple.

If there is more than one contractor performing the work, you probably need to break down the work further. If a series of activities are all running concurrently, perhaps it would be best to break the work down into smaller areas. The goal is to use Start-to-Start and/or Finish-to-Finish relationships as little as possible. Using Finish-to-Start relationships is almost always the best way to model the work. This usually requires breaking the work down into smaller pieces…

I’m sure many of you have comments or additional insight into this subject. Please share!

I’d love to hear what you think!

Please visit https://conschmanservices.com to learn more about Construction and Schedule Management Services, LLC

Please visit my LinkedIn account to learn more about me.

Please visit my “The Blue Book” ProView.

Paul Epperson CCM, PMP, PSP, PMI-SP

Construction Scheduling. General Progress Update Information for Owners.

When we develop the Baseline CPM Schedule for a construction project, we know we will need to use the Baseline CPM Schedule to measure performance during project execution. With this in mind, we work with the contractor to help get an acceptable Baseline CPM Schedule for the project. That’s usually a tough task, many contractors don’t believe it necessary or simply do not want to follow parts of the schedule specifications or best practice for schedule development. But, we usually end up with a schedule we can use to track progress and manage the work and changes.

I often see problems on projects once we start getting schedule updates from the contractor. Some owners believe the Original Baseline CPM Schedule is the most important schedule we measure against. This is partly true, we do need to reference the original plan as we go. But, after the first couple of progress updates, the remaining plan to execute the project has changed. Sometimes there have been major change orders, delays or resequencing of work. When this happens, we need to revise the Baseline CPM Schedule. Most of us understand the need to re-Baseline.

What I find many do not understand is how important it is to keep the progress updates valid. The owner really needs to be able to validate Actual Start and Finish dates in addition to agreeing with the partial progress reported for work in progress. These three items determine the as-built schedule condition and establish the plan to continue with project execution.

That is what the owner can see in the Gantt Chart pdf.

What about what goes on behind the scenes when the contractor is applying the update data? Who is watching to see if logic is changed? If calendars are adjusted? If resources are revised?

There are many things the owner cannot verify or validate that absolutely need to be confirmed. This is where the Owner’s review and oversight of the scheduling process come in to play.

With each progress update submitted by the contractor, we look at several areas to ensure the schedule integrity is maintained.

First, we simply make sure the network logic is still complete. This also includes verifying there are not any open ends such as a Start-to-Start, SS successor relationship which leaves the finish of an activity open. We run diagnostics to uncover what logic, durations, calendars, and activity additions/deletions have been revised and analyze this data to understand what the changes actually do to the schedule. We need to determine if the contractor’s revisions of a few relationships from Finish-to-Start, FS to SS shortens a network path enough to shift the Critical Path. It may be unintentional, but we must still review and validate. Sometimes these relationship revisions are done to correct Out-of-Sequence, OOS logic, sometimes it is done to recover lost time and bring the schedule completion back.

We look for calendar changes which often affect Total Float and the Network Path. We look at changes to durations and flag lack of progress for activities not projecting to complete as planned. This needs to be investigated to determine the causation. We verify Out-of-Sequence Logic has been corrected to keep invalid relationships from driving remaining logic and dates.

We analyze the actual progress of the project as a whole and also look at the Critical Path work performance as well as Near Critical Path(s) work performance. Doing work on the Critical Path is important. Doing work on the Near Critical Path(s) is also important. However, if work not yet Near Critical is not executed aggressively, the result in the stacking of work adds unachievable resource demand to the remaining scheduled work. This often drives the search for the “miracle” towards the end of the project….

We have to monitor all this, and you really can’t get that kind of insight from the Gantt Chart pdf.

We have to validate the progress update schedule. After all, the revisions to pull back the schedule and make minor sequencing changes have obviously resulted in logic or other changes. We need to verify that the schedule still meets the schedule specifications and best practices. Each progress update becomes the basis for any time impacts for the next performance period. The schedule update has to be valid.

I will elaborate more on how we accomplish many of these tasks in future posts.

I’m sure many of you have comments or additional insight into this subject. Please share!

I’d love to hear what you think!

Please visit https://conschmanservices.com to learn more about Construction and Schedule Management Services, LLC

Please visit my LinkedIn account to learn more about me.

Please visit my “The Blue Book” ProView.

Paul Epperson CCM, PMP, PSP, PMI-SP