Schedule Management – Page 2 – Construction and Schedule Management Services

Construction Scheduling. What are the Critical and Near Critical Paths? Why do we care?

When the schedule is developed, the schedule logic should be complete. All activities should have at least one predecessor and one successor, with the exception of the first and last activities for the schedule.

If this is done, the combination of activity durations, activity calendar assignments, and schedule logic create the CPM schedule network. This CPM schedule network is made up of many sequences (logic paths) of activities.

In simple terms, the longest continual path from the project start to the end of the project or the next hard constraint establishes the Critical (Longest) Path.

The Total Float values are a just the product of the forward and backward pass through the CPM schedule network. Just because the Total Float value is zero does not make the activity critical.

However, the Total Float values are important. If the Critical Path has a Total Float value of zero, then the Near Critical Path activities will most likely have a Total Float value very close to zero. I say most likely because the activity calendar assignment has an impact on the Total Float values. But often, this is a simple rule of thumb for determining the Near Critical Path. I like to keep an eye on work that is on the Critical Path first and then also pay attention to work that falls on the Near Critical Path(s) within one or two weeks of the Critical Path for large projects and a few days for small projects.

It’s not unusual for the PM and Superintendent to focus on work on the Critical Path and not pay enough attention to work on the Near Critical Path(s) and then have the Critical Path shift because a lack of progress for the Near Critical Path work took over the Critical Path.

This is just one reason complete logic, calendar definition and assignment, and limiting constraints are important when developing a baseline CPM schedule. If you scatter constraints throughout the schedule, you will not have a true Critical Path for the project. Without complete logic, you do not have the means to accurately complete the forward and backward pass that establishes the CPM schedule network scheduled dates and Total Float values. Without calendar definition and proper assignment to activities, durations will be erroneous and this will ultimately produce a false schedule network.

I know many of you can offer additional comments and recommendations. I welcome your comments and input. My goal, as always, is to help our industry and help the projects we support….

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. Layouts and Options for Layouts.

Do you ever look at a schedule pdf and get lost in the many pages of data and bars?

Would you like to be able to quickly find out what is most important to you, as a PM? As an Owner? As a subcontractor?

When your contractor develops the project baseline schedule, they develop several activity code structures for the project. (Or they should…) We typically set up activity coding for phases, areas of work, subcontractor or trade responsibility, cost accounting source, CSI Division….

We do this so we can assign specific code values to each activity. This allows a filter or sort or group on specific or combinations of activity code values. We can filter by trade and sort by start. We can then group by area or phase or building. There are many ways to view the schedule which can make it easier for everyone.

However, often what you find in a progress or owner’s meeting is the two or three week look ahead schedule. This is a good tool. But, it is a specific tool. The look ahead schedule layout can show the work by phase or area or trade or simply as a “waterfall” by start date. The project team should decide what works best for them and request that layout for each meeting.

There are other layouts, in addition to the look ahead and the entire project schedule that are very useful.

One layout that I always use is the Critical Path (Longest Path) by Start/Finish date with no grouping. This provides a simple view of the critical activities by start date in a “waterfall” view. Very helpful for seeing what is critical and next in line.

I also like to produce a filtered list of incomplete and not-started activities sorted by Total Float value and then Start/Finish. No grouping, just a “waterfall” again. This allows us to see what is most likely the Near Critical Path activities by simply going down the list to the paths after the Critical Path. (I use a filter to remove the Longest Path) This is very helpful to the PM and Superintendent. They can ensure they focus on work that is near critical as well as critical. Too often this is missed.

Those are very simple layouts.

There are options for the Project Team. Let the scheduler show you what they can produce and work with them to find layouts that work for your project. It will make managing work much easier for everyone.

I know many of you can offer additional comments and recommendations. I welcome your comments and input. My goal, as always, is to help our industry and help the projects we support….

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. Total Float Values and Calendars.

Do you ever look at a schedule and wonder why a series of related activities will have different Total Float values? Perhaps the activities on the Critical (Longest) Path?

It just makes sense that the activities in the same work path would have the same Total Float value.

However, when your contractor develops the project baseline schedule, they develop the various Activity Calendars for the project. There may be a 7-Day Work Week Calendar for Milestone Activities, Level of Effort Activities, and fabrication or delivery activities. There may be a 5-Day Work Week with Holidays Calendar for work planned for normal work days but not on holidays. There may be a weather calendar with specific days set as non-work days to allow for the anticipated normal weather impact days.

Each calendar will have a different action on the Total Float value because each calendar only allows the work to be scheduled on the work days for that specific calendar. This, in turn, determines the Total Float value.

This is why the Milestone Activities on the Critical Path may have a value of -7 days and the activities on the 5-Day Work Week Calendar may have a value of -5 days. The 5-Day Work Week Calendar doesn’t take the weekend non-work days into account with the calculation. The total Float value for the activities assigned to a weather calendar would also be different.

This is also why a set period impact to the schedule, such as 30-day delay in receiving direction to start work on a work package could have a larger delay to the contract completion. A 30 Calendar Day impact can push the work over non-work periods such as holidays and weather resulting in a 35 Calendar Day impact to the contract Completion Date. This must be accounted for in the Time Impact Analysis so the party not responsible for the delay is not forced to absorb this variance.

The bottom line is: Don’t let Total Float values determine what is critical, let the schedule software do that by using the Critical Path definition of Critical = Longest Path. Using the Total Float values is valid for many things, but determining your Critical Path isn’t one of them. If you have more than one calendar for the activities, there will be differences in the Total Float values.

I know many of you can offer additional comments and recommendations. I welcome your comments and input. My goal, as always, is to help our industry and help the projects we support….

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. Let Durations Help You.

How can you use the Activity Duration value to help you manage your schedule?

Simple, just look at all the columns and do some math in your head.

When your contractor develops the project baseline schedule, they develop the Original Duration for each activity. How they develop the durations is a subject for another post. But let’s assume they have used historical data, input from subcontractors, calculated productivity and quantities, or some method of developing an accurate value for the each Activity’s Original Duration.

Most Schedule Presentations (Gantt Chart pdf’s) have the activity names, dates, a percent complete and a duration for each activity shown in columns. Then there are the magical bars to the right. Sometimes there are even relationship (logic) lines drawn from activity to activity so you know what drives what, right? Can you actually read it? Doubtful…. Anyway, let’s focus on the duration columns.

If you’re looking at a Schedule Presentation from a Primavera P6 schedule, there are options for which duration columns you can see. Almost everyone uses the Original Duration column. Most of us use the Remaining duration column. That’s all we need to know, correct?

Not really, there is a column that shows the At Completion Duration. This is not seen in presentations that often, probably because we want more room for the magic bars and lines… But this is an important column to be able to see when reviewing a Schedule Presentation pdf.

If you have an Original Duration of 5 days (Work Days or Calendar Days depends on the Calendar. This is a subject for another post), and a Remaining Duration of 3 days and the percent complete (whether it is Physical, Duration, Activity, Performance, or Cost or another type is a subject for another post), is 50%, things are looking good, right?

Not always. If you look at the At Completion Duration, you may find that while the Original Duration is 5 and the Remaining duration is 3. But the At Completion Duration could be 35 or any other value if the activity finish date is riding the Data Date. This can happen depending on the settings used to manage the schedule. Unless you actually look at the dates and do some calculations in your head while reviewing the schedule, when you don’t have the At Completion duration column to use, you may not see the slippage.

Ask your contractor to display the At Completion Duration column for their Progress Meeting Look Ahead Schedules and any other pdf submission. It’s worth the trade off with the magic bars and lines!

Knowing what was planned, what is remaining and what the time impact of activity progress slippage is can save you some trouble.

I know many of you can offer additional comments and recommendations. I welcome your comments and input. My goal, as always, is to help our industry and help the projects we support….

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. Do You Manage Your Project with the Project Schedule?

Question Why would you not use the schedule to manage the project?

If you put the effort into developing a detailed CPM schedule with input from the project team members, isn’t the schedule the best road map you have?

One of the great opportunities development of the baseline schedule offers is the project team’s review and input into the analysis of the scope of work for the project.

Depending on how your company estimates and proposes on projects, the people charged with executing the project after the award of the project to your company may have had limited to no involvement or exposure to the project requirements and the basic plan to execute the project based on the proposal.

The schedule development process encourages the project team to review the requirements, understand the sequencing of the work and sometimes even uncover an opportunity to improve on the initial proposed plan.

Assuming the project team has developed a great detailed baseline CPM schedule. I can’t imagine why anyone would not use the schedule to plan and manage work. Management likes to use the schedule to track and measure performance, but I consider the project schedule to be the project team’s best tool for executing the project.

Unfortunately, I run into projects that only produced the baseline schedule because it was required. The progress updates were used for invoice backup only and no effort was put into accurately updating and correcting out-of-sequence work and revising the plan to complete the remaining work in the project. Sadly, these projects do not have a valid schedule to base change order and delay impacts on. They also do not have an accurate idea of if or when the project will complete, much less what is required to get there.

There are many reasons to develop and use a detailed CPM schedule to manage the project. I can’t think of a good reason not to.

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. Resource and Cost Loading the Schedule

person-question-300x300 Once you have the basic CPM schedule development completed and you’re ready to start resource and cost loading, do you find the schedule specifications lacking in requirements or guidance for this part of the schedule development?

Some schedule requirements simply do not require resource or cost loading. Some require the assignment of resources but do not speak to cost. Some allow simple lump sum cost loading, some require unit pricing with equipment and material costs broken out.

Whatever the case, most of us prefer the schedule be cost loaded, at least the baseline schedule. This allows us to create the performance measurement cost curve for EVMS and the early and late cost curves many of us are familiar with and most specifications require.

Each planning and schedule professional will have their own preferences for resource and cost loading the schedule.

Myself, when a lack of requirements allows, I prefer the resource and cost loading be kept simple. Unless the payment process for the project is based on unit prices and crew pricing, I avoid unit pricing with equipment and material costs broken out. I work mostly in mid-size construction projects and find that lump sum cost loading works just fine.

One thing I prefer is to keep my percent complete type set to physical and make the cost percent complete equal the physical percent complete. I find this works well if the delivery of large equipment is cost loaded and work activities are assigned cost which includes labor, equipment and basic materials. Simple to develop, manage, understand and track. Remember, this is for general construction. Road, UG infrastructure, and other linear unit driven schedules will benefit from unit pricing.

I also like to assign a resource for each subcontract, even though I lump-sum cost load. This allows a resource or cost curve for each. This helps with resource level analysis.

I believe resource and cost loading of schedules is an underserved discussion topic and our industry as a whole would benefit from learning how various industries and project types approach this process.

Hopefully, this post will help start some dialogue among us.

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. Reviewing a Time Impact Analyses, TIA or Change Order Fragnet. Or, “Is this for real??”

Surprise I am sometimes bewildered by the reaction some owners have when they review the Time Impact Analyses, (TIA) or change order time extension request they receive from the contractor.

What I see, sometimes, is the owner being completely surprised that the contractor believes there was any time impact by the change order or delay. We all know that many change orders do not affect the project schedule critical (longest) path. But when they do, it gets interesting….

Let’s say the owner has delayed some part of the project in some way, but only for 3 days. When the contractor submits their TIA or change order time extension request for 5 days, the immediate reaction is usually not so good.

I find this happens more often than not because the owner does not understand how work days and calendar days work and their effect on the contract finish date.

If the 3 days happen to be 3 work days delay to the start of work on a 5 day work week calendar, it is most likely going to push the work out to include a weekend “non-work” period, perhaps even a holiday. If this happens, it will most likely push the scheduled finish date out 5 calendar days. (Most contracts have the liquidated damages based on calendar days.) In this particular case, the impact to the schedule is 5 calendar days, not 3 days.

This is can also the case when weather-sensitive work is pushed into time periods with more expected and accounted for weather days. As it should be.

How can we, as professional planning and schedule consultants help owners better understand the TIA’s and change order time extension fragnets they receive?

There are best practices and white papers devoted to the development of “fragnets”. As professional planning and schedule consultants, we should follow these best practices. But, we also need to review TIA and time extension requests to verify the “fragnet” correctly models the impact and is inserted into the most recent updated or revised schedule with reasonable logic.

Then we need to explain that to the owner to refute or validate the request. I find that once the owner understands what is driving the time from “behind the scene” in the schedule network, they tend to be more comfortable with the request. Then the negotiations can start!

None of this is possible, of course, unless there has been a disciplined process of managing the schedule development and update/revision process to maintain a valid schedule for use in validating the requests.

What other methods have you found to help with this issue?

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. Developing trust with the Owner, for Schedule Management.

person-question-300x300 I often assist contractors with their schedule development and updates. This also includes preparing the “fragnets” for Time Impact Analysis, (TIA) or change orders. I get the impression from many owners that they do not trust the fragnet or analysis supporting the time extension request.

I worked many years on the “owner’s side” of projects. I understand the concerns most owners have. It only takes being lied to once to create a skeptic…

How do we, as professional planning and schedule consultants overcome the widespread distrust owners have, specifically when it comes to developing and supporting fragnets, TIA’s, or change orders?

I find the majority of contractors I work with to be honest & above board. They act with integrity and genuinely want to provide the best product and service they believe the owner has contracted for.

I find the majority of owners I work with believe they have provided the contractor with a good set of contract documents to work with and really do want the contractor to be successful on their project.

I believe the most important thing we can do, as professional planning and schedule consultants, is educate our clients by teaching them how the time impact “plugs” into the schedule; how the various calendars with non-work days affect the scheduled dates and total float downstream of the fragnet; how to properly manage the schedule updates and revisions to use the correct schedule to base the impact on.

If we could teach our clients the basics of change management for schedules, they might have a better understanding of what is prepared and presented, which would perhaps help in making the “negotiation” of the time impact go smoothly.

Who knows? It just might help build a little trust on the project…

What other methods have you found to help with this issue?

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. Don’t let the Near Critical path Sneak up on Your Project!

Surprise Do you diligently keep track of the work on your project’s critical path?

How we define the critical path is a topic for another time. For now, let’s just focus on what we are tracking as critical based on total float values, which do tie into the longest path definition with variances for calendars…..

How often has the critical path for your project shifted during the project duration? Do you show as much diligence with tracking the near critical activities as you do the critical path activities?

You should, and I’m betting that you do. But, sometimes, it still sneaks up on us!

I prefer to keep my eye on both. And then I usually only focus on the nearest couple of near critical paths. 80/20 rule….. By staying aware of the calendars assigned to the activities on my near critical path(s) and looking at the trend for slippage for these activities, I generally find I realize the pending in time to intervene. I like that much better than after the fact, but I’d like to deal with the pending impact sooner, as I’m sure we all would.

I do this by comparing the past near critical path activities to the current activities to look for slippage in my layout and filter. This helps. I also like to track the schedule slippage of the activities with a total float value lower than a specific total float value dependent on the schedule status. I find it easier to spot the start of the trend and make a note to track that activity next update. I then look at the drivers to see what is causing the slippage. Pretty simple. There are more elaborate methods of analysis for determining trends and slippage and identifying potential impacts, but I like to start with the simple methods to get an immediate fix on the schedule status.

There are always “exceptions to the rule”, but this is one I try to follow.

What other methods have you found to successfully identify the near critical path negative trend?

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. Spotting a Potential Resource Issue Early. Or, Why isn’t my Contractor Keeping up?

Question Would you like to be able to spot a potential contractor or subcontractor production shortfall early? Perhaps get ahead of the lagging work?

There are many ways to mine this info and establish the trend. I’ll offer a very simple method for P6 here.

If you set the percent complete type to physical, display the physical percent complete and the duration percent complete columns along with the start and finish date columns, you can spot potential production issues quickly when you update.

Personally, I like to run my cost based on my physical percent complete, but different project types require different methods….. But for this method, we will be basing the cost complete on the physical percent complete prorated over the entire duration.

Once you have the actual start date and physical percent complete you should enter the expected finish date to establish the revised scheduled finish date for the activity. Doing this will result in a different duration percent complete than the physical percent complete you entered based on actual work completed. The variance will show if the production rate for this work was accurate as actualized to date or if the actual production rate is better or worse than planned.

If the work is 50% physical complete and the adjustment to the scheduled finish date forces the duration percent complete to be 65%, you may want to investigate to find out if the original assumptions were incorrect or if this resource is adequate to meet the production as planned. If the same resource is having problems for several activities, there could be a trend that needs attention.

Simple. There are more accurate ways to measure this, such as resource man hours or units completed. But this is a quick, easy way to spot an issue just by looking at the schedule as you update or look over the schedule in a meeting…..

What other “easy” ways have you found to monitor the work and spot potential production issues?

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