Month: August 2017

Construction Scheduling. Activity Codes and Organization.

When the schedule is developed, how do we determine the Activity Coding for each activity?

What is an Activity Coding Structure?

Many PM’s don’t know or care about the Activity Coding. Unfortunately, they are missing out on the use of a great tool.

I’d like to offer several reasons for spending the time and energy to develop and use Activity Coding.

Activity Codes are developed for the schedule based on specification requirements and a Schedule Management Plan. It can be as simple as a specific assignment for phasing. More often an Activity Code Structure is developed to include specific phasing of the project, responsibility for work, areas of work, CSI assignment, weather sensitive or not, and type of work.

I like to develop the schedule Activity Code Structure prior to building the activities out. I usually do it when I set up the calendars, resources, and WBS. After all, it is based on the plan for organizing the schedule and reporting for the various stakeholders. It is also used for schedule analysis.

Once the Activity Code Structure is set up, (Along with the calendars and calendars, resources, and WBS) we can start building out the activities for the project schedule.

If you develop the string of activities for a specific trade, which is how I usually start out the development of each trades’ work, it is easy to assign the resource and activity coding as you assign the activity calendar and resource. By having already established the Activity Code Structure, there is already a ready list of choices. This prevents inadvertently assigning similar coding for the same item.

So, we develop all the activities by WBS with the appropriate activity calendar, resource and Activity Coding.

Now we can sort and group in a multitude of ways based on the Activity Coding Structure we planned and executed.

We can group by responsibility and sort by Start Date if we have already assigned the logic. Or we can sort by Activity ID if we added the activities sequentially in the order of execution. This makes it easier to manage adding the logic. We can then group by area to see how we need to coordinate the work between trades. This is very handy for establishing preferential logic.

We most often use the Activity Coding for Layouts and presentations.

Grouping the schedule by phase and then area is a popular layout.

We can also filter by responsibility which allows us to analyze the planned sequence for each trade and verify scope. If the logic is complete and there are many activities planned for the same work period, resource allocation may be an issue. This layout allows us to assign preferential logic to assign resource flow.

There are many reasons for developing a robust Activity Coding Structure. We use them often and they offer a great method of organizing the activities for analysis.

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. Activity Durations and Unicorns.

When the schedule is developed, (after the project has been broken down and organized into the WBS and the activities have been developed to support the deliverables), how do we determine the duration for each activity?

How do we accurately determine the work period for each activity?

There are several ways this task is approached. Some are better than others….

I believe we can all agree that knowing the required work quantity and production rate per day is the best input we can have to accurately calculate the duration. How often do we actually have that much detail?

More often, the project team determines the durations based on their “feel” for how long the work will take based on similar work from the last few projects. This is not necessarily a bad thing. This is historical data and is very useful.

The problem is that we tend to be optimistic. The larger the piece of work is, the more difficult it is to accurately determine the duration, by “feel”.

Typically, the activities are all developed based on input from the project team, the constrained finish date is applied and then the schedule is “calculated”. Usually, we do not make the required finish date.

Now we start crashing the schedule to pull the finish date back.

We’ve all seen videos of buildings constructed in a week and other supernatural feats. So, it stands to reason that we can build anything within any timeframe, right? If the owner wants the project by the date in the contract, we have to crunch the schedule until it shows we can deliver on time.

As we know, a very high percentage of projects do not finish on time. This often leads to claims and poor performance reviews.

Is it possible that we set our projects up for failure at the very beginning? Do we assume we can provide a finished project within the contract duration just because the owner has specified the period of performance?

If the schedule is constructed using “most likely” durations for all activities with reasonable logic and the project is then constrained to finish on whatever date that produces, there is still a good chance the project will finish late. It could finish early, but that seldom seems to happen.

If the durations are based on pessimistic durations, the project will still tend to use the time allowed leaving little room for problems towards the end of the project.

If we place a contingency activity at the end of the project, we can work towards an early completion hoping we magically finish on or ahead of time.

Or, we can put the effort into building very detailed schedules with solid logic and durations and then execute the projects per the schedules, as well as possible.

Any way you slice it, a poor schedule does not work. An aggressive schedule is not realistic and will soon fall apart, a pessimistic schedule will also fail due to a lack of aggression to complete work.

A detailed schedule, with input from all team members, does not guarantee success, but it does provide a realistic path to get there. It is up to the project team to execute based on the plan. But they can’t do that without a solid schedule.

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. Critical Path and Total Float.

Can the Critical Path for a project have different Total Float values?

Does the Total Float value determine the Critical Path?

When the Baseline Schedule is developed, all the activities should have the appropriate calendars, durations and logic applied. This creates the schedule network of activities.

Within this network of activities, there are many paths which run through activities linked by mandatory or “hard” relationships. For example, the structural steel shop drawing development and submission should drive the review of this submittal which will then drive the procurement with lead time to drive the delivery and then the erection. Almost all the trades and materials have these “hard” relationships which form the work sequence for that network path.

There are also discretionary or “soft” relationships. For example, the ACT grid could be installed prior to the wall painting. I prefer to run the grid after the walls are painted, but it may be necessary to install the grid first to allow light fixture and register installation to start earlier. This may be sequenced at the discretion of the Project Manager or Superintendent.

There are external relationships, but these are usually handled within the schedule itself. But it is possible to link activities in one schedule to work in another schedule….

Once all the mandatory and discretionary relationships are assigned, and the calendars and durations are assigned we can “schedule” the project. This is what sets the schedule network up.

This is what also determines the Longest Path and Total Float values.

If there is not a finish constraint applied to the project, the end date will float dependent on the network. The Total Float value will be 0. If you sort the activities by Total Float value and look for the next continual sequence of work activities with a Total Float value close to 0, you will most likely find the Near Critical Path. Just be aware that this Near Critical Path is based on the Total Float values only and will not necessarily be the logical Near Critical Path.

If you have a constrained finish date for the project, the Baseline Schedule should have a Total Float value of 0. But as soon as you start updating actual progress, the work will force the various network paths to push or pull and this will change the Total Float values. The Longest Path will still be the Critical Path, but the Total Float values may be positive or negative values. Again, the next continual sequence of work activities with a Total Float value close to that of the activities on the Critical Path should be the Near Critical Path, based on Total Float values only.

Recognizing the Critical path is the Longest Path is the basis for properly managing the work. Recognizing the usefulness of the Total Float values for identifying Near Critical Path work is also valuable.

This is a fairly simple concept. But, there are many discussions about what determines the Critical Path.

Not using Longest Path as the definition to use Total Float values is a tool we use for analysis. Much as we use Progress Override instead of Retained Logic for analysis.

Interim Constraints play into the schedule network and affect the Longest Path and Total Float values. But this is another subject for the future….

I’m sure many of you have additional insight into this subject and can help explain the concept. 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