Facing a project deadline can feel like a race against time for you. It’s a familiar scene: the clock is always ticking, your team is rushing.

The threat of being late is always there. This is where ‘Project Float’ comes in – It can help save your project from constant delays.

It’s tough to see your projects getting delayed. You watch the due date getting closer and think, “Can I make a difference here?”

The great news is: yes, you can.

Think of yourself as the leader who helps the team avoid delays and guides them to success. You’re moving from watching from the side to taking charge.

In my early days, I didn’t know how to use our schedule to avoid delays. I didn’t make the most of ‘Project Float’ to handle unexpected issues.

I couldn’t show them how to stay on track because I didn’t get how important the project float was. So, I didn’t get the recognition I hoped for. But, learning to use the project float and tracking them changed everything.

I’m here to guide you with 5 practical steps to master Project Float. You’ll gain the tools to track, manage, and apply it to your project. Ready to become the go-to expert your team relies on? Let’s get started.

1 – Understand What Influences Project Float

Ever started using a new tool and skipped the tutorial, only to get stuck later? That’s common with project planning, especially with project float. If you’re new, you might not get how float works.

Remember: if you put the wrong info into software, it will mess up your project’s float. Why? Project float’s tricky because lots of things can change it.

Beginners often rely too much on software and end up with errors. But, knowing what affects float can help you avoid those mistakes and guide your team better.

So, what affects project float? Here’s a simple explanation:

Activity Duration

Shifting gears in a car change its speed and control. Similarly, adjusting activity durations can change a project float. It affects how you can meet the deadline.

Imagine the scenario from our schedule below:

‘Brick Selection and Procurement’ in Float Path 2 has a 20-day float. How? Easy. Subtract Path 2’s duration (77 days) from Path 1’s (97 days).

This means you can push these activities back by up to 20 days without impacting the deadline.

But, there’s no room for delay in Float Path 1, our critical path (longest path), which takes 97 days. Any hold-up here delays the whole project.

Like Figure 3, If ‘Brick Selection’ and ‘Brick Procurement’ extend by 20 days, both paths become critical. It increases the risk of delay.

Schedule Network Diagram with Project Floats (20 Days on Float Path 2)

Gantt Chart Schedule with Project Float (20 Days on Float Path 2)

Key points?

Always review activities for a longer duration to see if they need all that time. And if you’re trying to speed up the project, think about shortening some activities.

This could help finish the project sooner, but make sure the team is on board and you have a plan for any risks.

Gantt Chart Schedule with Project Float (Zero Float on Float Path 2)

Activity Sequencing

Project float isn’t about how long tasks take. It’s also about the activity sequence. If you change the logic, the project float changes, too.

Take this scenario: The team decides to do ‘Doors and Window Work’ after ‘Roof Works’. This switch removes Float Path 3 and extends Float Path 1 from 97 to 107 days. Float Path 2 then becomes 87 days. So, the total float for Float Path 2 ends up being 20 days (107 days minus 87 days).

The key point?

The activity sequence really matters. Why? It affects your project float and duration.

To finish your project faster, consider changing the tasks’ sequence. Not just changing how long they take.

Activity Calendar

Project float isn’t just about duration or its sequence. It also depends on the activity calendar.

For instance, the ‘Engineering (90% Design)’ activity isn’t seen as critical. Why? It’s because of its successor—the board approval meeting’s calendar. It happens once a month.

The result? The critical path commences at the board meeting, not the project’s start date.

The takeaway?

Use the longest path, rather than focusing on activities with no float.

Here’s how you can do it:

Activate the ‘Longest Path’ option in P6’s schedule settings. This ensures you catch every critical task.

Critical Path Schedule Using Longest Path Option

Project Deadline

Imagine you’re planning a project, thinking you have four months to get everything done. This plan gives you some extra space to make changes if you need to.

But then, surprise! The deadline gets pushed up to 3.5 months. Suddenly, your float shrinks. You get negative float unless you rejig your schedule.

People handle deadlines differently. Some put constraint on a key milestone with a ‘Finish On or Before’ date, creating a deadline. Others set a deadline for the whole project at the project setting with ‘Must Finish By’ date.

I used to get confused about why I sometimes had more or less project floats than I thought. Then, I realised it was because the end date set in the project file.

The fix?

    • Always check if the schedule has already set a deadline in the project settings.
    • Then, update the deadline if required.

Setting a deadline reshapes your project’s float. It makes you rethink which activities are most urgent. When you hit delays, figuring out which tasks to prioritise can be tricky.

But, don’t worry; I’ve learned a few tricks to sort this out and will share more soon. So, stay tuned for the next updates.

Does Soft Constraint Matter?

You’ve probably heard this advice a lot:

  • Putting constraints on your project schedule isn’t the best move.
  • You should avoid ‘hard constraints’ like ‘Finish On’ or ‘Mandatory Finish.
  • It can make the schedule less reliable.

So, it’s common for you to think ‘softer constraints’ such as ‘Finish On or After’ or ‘Start On or After’ might be okay.

But, even these soft constraints can mess with how you calculate your project float.

I remember my time at a major mining company. We were evaluating schedules from another team. The recommendation? It was to use a dedicated calendar for shutdown instead of constraints.

The reason? Constraints mess with the accuracy of the Critical Path Method (CPM).

Take the scenarios below:

Scenario 1 – Critical Path with Constraints:

Imagine your project has constraints like ‘Start On or After.’

You’ll find the schedule doesn’t show the longest path because these constraints disrupt the CPM.

Scenario 2 – Critical Path without Constraints:

Now, think about removing those constraints.

Suddenly, the longest path becomes clear in float path 1. This shows that your project can display a proper critical path once you get rid of constraints.

The takeaway?

Relying too much on constraints can derail your project. Sticking to a simple calendar setup is a better option.

Now you know even softer constraints can change how your project floats. But did you know a little-known constraint called ‘As Late As Possible’? This also influences your project float.

Why As Late As Possible Screw Up Your Project Floats

During my time reviewing schedules for EPC contractors, I stumbled upon a common yet tricky constraint: ‘As Late As Possible’. I know it’s for a specific purpose. For example, the required on-site (ROS) date for equipment and material delivery.

But, my suggestion?

Avoid it unless absolutely necessary.

Here’s why: ‘As Late As Possible’ pushes activities to their latest start dates. The result? It makes them appear as critical with zero float. Why? Their end dates are tied to the next activity’s start.

Take brick procurement as an example. Without this constraint, it’s not critical and enjoys a 20-day float. When you apply ‘As Late As Possible’, it suddenly looks critical.

This shift can confuse your team. Activities that weren’t critical now seem critical. Muddling which activities need immediate focus.

The lesson here?

Use ‘As Late As Possible’ sparingly to keep your schedule clear and reliable.

Critical Path without Constraint

Critical Path with ‘As Late As Possible’ Constraint

Getting a handle on what influences your project float is vital. Reason? It allows you to fine-tune your schedule effectively. Yet, that’s merely the starting point.

The next step is to scrutinise the float values your scheduling tool provides. It’s not enough to take them at face value. You need to confirm that these numbers are realistic and truly reflect your project’s float. Are they realistic, or optimistic estimates?

Let’s dig in and verify the accuracy of your project’s float together.

2- Assess The Realistic of Project Float

Has your project team ever deviated from the schedule? It’s a common scenario.

Here’s what happens: I often get feedback from the team that the logic setup in this project is not right. The activity description is unclear.

Imagine a planner creates a schedule one way, but the team ends up doing things differently.

The planner discusses everything with the team. But the team doesn’t quite get the details in the schedule, especially with large projects.

This discrepancy leads to a gap between the plan and the team’s actual approach. Consequently, the project’s float in the schedule might not reflect reality.

I often face the question:

What’s the float for this task? In other words – the team ask if we have more time to complete this to reduce the team’s pressure. Must we complete it by next week to avoid impacting the deadline?

It’s hard to answer confidently if you’re not sure about your schedule’s real float.

The solution? Make sure your project’s float is accurately represented in your schedule.

1 – Validate Your Project’s Big Float

Wondering if those large floats in your schedule are correct? The first step is to verify them.

A large float can be helpful if they’re accurate – they help optimise resource usage and reduce stress. But if they’re not accurate, they can lead to missed opportunities, like extension of time (EOT) claims, and less accurate project completion forecasts.

Remember, project float depends a lot on activity sequencing. A large float could mean there’s a break in logic or incorrect task links.

Teams often think they have more time than they do. So, it’s critical to verify your project’s float is correct, as it can significantly impact your project’s success.

To make sure activity links are correct, especially in Primavera P6, follow the steps below.

How to Check Broken Relationships in P6

☑ Create a filter in Primavera P6 to trace the activities that do not have predecessor or Successor.

    • Select the Parameter “Any of the following.”
    • Then add the Parameter “Predecessors” is “equal” value “null” (leave it blank).
    • Do the same for Successors.

☑ Create a filter to find the uncompleted activity: find the activity that hasn’t been started or in progress.

☑ Finally, Select the “Activity Status Filter” and “Broken Logic Filter.”

2 – Review Negative Floats

Already checked for larger floats in your project? Next, look for any negative floats and figure out why they’re there.

Why check for negative floats?

    1. I always get feedback from the project manager and client that we need to come up with a recovery plan and don’t want to see negative float.
      • Because it suggests errors in the schedule or hints that your project might be having problems with schedule delays – (i.e. have a recovery plan to to tackle the delay or require approval for an extension of time).
    1. With negative floats, it’s tough to tell which tasks are most critical, making it hard to optimise your schedule for resources and dates.
    1. Don’t set your baseline schedule with negative floats around. Why? Because you can’t rely on the baseline total float to track your current schedule’s project float.
    1. You can’t use them for schedule risk analysis since they fail the quality check needed for such exercises.

Now you know negative float is bad for your project.

So, what’s behind negative floats? While there can be several reasons, these are common reasons:

      • Constraint Dates
      • External Links and Dates
      • Using Multiple Calendars with milestones

How to Check Negative Float Caused by the Constraints

In any project, you’re bound to run into constraints – it’s just part of the deal. But, it’s critical to know what constraints are in your schedule and which ones are causing negative float in your P6 schedule.

Here’s the thing: certain constraints can lead to negative float, especially when your scheduled dates stretch past the constraint dates. These are called hard constraints. Look out for these in your schedule:

    • Finish On
    • Finish On or Before
    • Start On or Before
    • Start On
    • Mandatory Finish
    • Mandatory Start

Try to avoid these constraints if you can. But if you must use one to show that your project is in trouble, go for constraints that start with ‘Finish On or Before’ or ‘Start On or Before’. These types still let you calculate your forecast date.

For example, when setting a project completion milestone, use ‘Finish On or Before’. If you look at the schedule below, you’ll see negative floats popping up because the project’s forecasted finish is later than the constraint date.

Also, If you’re taking over a schedule from someone else, just apply a simple filter for primary constraints and check out the constraint dates. This way, you can quickly see what constraints are already in the schedule.

Here’s how to find them easily:

    1. Finding the Columns (Primary Constraint and Date) – Not sure where these columns are? Just go to ‘View’, hit ‘Columns’.
    1. Use the Find Feature – Click on ‘Find’ to bring up a search box, and type in ‘Primary’ to get these columns.

    1. Filter for Primary Constraints and Date – Lastly, select ‘Start Constraint’ filter and ‘Finish Constraint’ filter in P6 to check activities with constraints.

How to Review Negative Float Caused by the External Links and Dates

Check Negative Float with External Dates – I’ve heard many times from my fellow planners saying – “I can’t get rid of negative float, but I didn’t have any constraint in the schedule.”

When you bring a project from another database, any missing links between the activities get replaced with ‘External Early Start’ and ‘External Late Finish’ dates. They act like constraints but don’t show up in the usual constraint date field in P6.

Wondering if your schedule has these external dates?

Here’s how to spot them easily:

  1. Add Columns – Pop in the ‘External Early Start’ and ‘External Late Finish’ columns to your schedule layout. Then, use a filter to check them out.
  1. Finding the Columns – Not sure where these columns are? Just go to ‘View’, hit ‘Columns’.
  1. Use the Find Feature – Click on ‘Find’ to bring up a search box, and type in ‘External’ to locate these specific columns.

  1. Filter for External Dates – Lastly, set up a filter in P6 to sift through activities that have these external dates.

Check Negative Float with External Links – If your project is linked to another project with constraints, it might cause negative float in your project. This negative float stays, even when you open your project alone.

To figure out which links are causing this, open all the projects linked to yours.

How to Validate Negative Float Caused by the Multiple Calendars

Got a negative float in your project and using several calendars? This could be why. I only faced this issue when I managed projects with multiple calendars.

Here’s what to do:

    • Remove any external dates and hard constraints first.
    • Then, hit F9 to refresh your schedule and see if the negative float is still there.

If you’ve still got negative floats, they might be due to milestones set on different calendars. Check this by adding Calendar and Activity Type columns in your activity view and look for milestones.

You’ve now checked the cause of negative floats in your project. To clear them, simply follow the steps in ‘Clearing Negative Project Floats in P6’.

After clearing the negative float, review your critical activities to ensure they align well with your team’s expectations.

3 – Review Your Critical Path

Just starting out in project management and wondering what the ‘critical path’ is all about?

The AACE’s RP 49R-06 describes the critical path as the longest sequence of tasks in your project that you need to finish. These activities are critical because they determine the project’s shortest completion time.

Similarly, PMI’s PMBOK guide’s 7th edition tells us the Critical Path is the longest sequence of activities in a project. It’s this path that sets the limit for how quickly you can complete the project.

Consider a scenario from the project below:

The project has 4 float paths; out of these, only the longest one really defines when your project will be completed. That’s your target – always focus on this longest path to hit your deadline.

Remember, lots of things influence project float, which in turn defines these critical paths – sequences of activities with zero total float.

One major factor? How you link these activities. If activity logics are wrong, you’ll see unrealistic delays or incorrect critical paths popping up. So, double-check whether the critical path shown by the software actually makes sense for your team.

How to do that? Start with analysing project float. Ready to tackle critical paths in P6? Let’s dive in.

How to Review Critical Paths Using Total Float in P6

STEP 1 – Set the schedule option to ‘Total Float’.

By default, P6 has already set the schedule options to total float. However, I recommend you check the options to make sure the recommended options are selected. So follow the steps below:

☑ Go to ‘Tools’ , then ‘Schedule’ or Press ‘F9’ to get the schedule options screen.

☑ Select the schedule options to define the critical activities as “Total Float less than or equal to’. If you want to be conservative, you can make the critical activities for the activities with total float less than 5 days or whatever days or hours you want to choose.

And, make sure to select the ‘Mark open-ended activities critical’ and ‘Use Expected Finish Date’.

☑ Finally, filter the critical path activities.

STEP 2 – Sort the activities with start date or finish date, and check if they form like a ladder shape from the beginning of the project to the end.

If the critical path doesn’t clearly show activities from the start to the end of the project, it’s time to adjust the logic, constraints or calendar.

We’ll dive into the specifics on how to do this in the next section.

STEP 3 – Keep going even If you find the critical path activities from the beginning to the end.

Talk to your team about whether the critical path from P6 matches what they expect. Print out the schedule that shows only the critical activities, and another one with all activities, including the columns for predecessors and successors. This gives everyone the information they need to review the schedule in detail.

Here’s what I usually do:

Send out the PDFs first so the team has time to review the schedule. Then, we meet to go over the P6 logic together in real-time.

How to Review Critical Activities Using Longest Float Path in P6

For bigger and more complex projects, having the option to check the longest path is a great way to check the critical path activities show as expected.


Using the longest path option to check the critical path activities you will uncover the activities which are not the critical path using total float option.

To check the longest path activities follow the steps below.

STEP 1 – Set the schedule option to ‘Longest Path’

☑ Go to ‘Tools’ , then ‘Schedule’ or Press ‘F9’ to get the schedule options screen.

☑ Select the schedule options to define the critical activities as “Longest Path’.

And, make sure to select the ‘Mark open-ended activities critical’ and ‘Use Expected Finish Date’.

STEP 2 – Change the Advanced Scheduling Options Setting

To get P6 to show you the most critical paths in your project schedule, follow these steps:

    1. Go to Advanced Settings: First, go to the Schedule Options. Once there, you’ll find a tab labelled ‘Advanced’. Click on this tab.

    2. Turn on Multiple Float Paths: Find the option ‘Calculate multiple float paths’ and select it. Also, choose ‘Total Float’. This tells P6 to look at various paths in your project, not just the longest one.

    3. Pick the Final Activity for the Longest Path: If you want to see the path to the end of your project, select the last activity, like ‘Project Completion’. P6 will then show the longest path of the project.

    4. Select a Milestone for Specific Path Focus: To focus on a critical milestone before the project ends, like ‘Ready for shutdown’, choose that activity. P6 will highlight the longest path to reach this milestone, showing you critical activities for that deadline. Use this technique when you want to concentrate on critical tasks to meet an interim deadline.

    5. Set the Number of Paths to Display: You can choose how many different paths P6 shows you. Just enter a number, like 10, and P6 will display up to that many paths. Leave the ‘Display multiple float paths ending with activity’ box empty if you use this setting.

STEP 3 Organise the Float Path Layout

A well-organized view is key to making sense of your data:

Go to Views > Group and Sort by and group activities by “Float Path”. Ensure that titles and names/descriptions are visible for easy reference.

1) Under Group By column, choose “Float Path”.

2) Under Show: select tick “Title” and “Name/Description”.

STEP 4 – Schedule (Press F9) to See the Result

Alright, you’ve made it through the steps, so here’s the fun part: Press F9 and watch the magic happen: float paths light up your screen. Go ahead and save that layout once it pops up.

You’ll see float paths as you’ve defined. But, a heads-up: skipped the baseline setup? Then you’ll miss out on key details like the baseline total float, and baseline finish variances.

4 – Ask For More (Get to the Heart of Your Schedule)

Have you ever sent off your schedule to question if it really captures the critical path accurately? But checking the schedule for Critical Path is just the start.

Steven Bartlett once said, “Ignoring the small stuff leads to big problems. Success is all about paying attention to the little details.”

So, how do you ensure your project schedule is right? Here’s what you need to know:

    • Ask, Then Ask Again: Don’t settle after the first round of questions. If you’re wondering about how activities are sequenced or their durations, keep the inquiries coming. It’s the only way to uncover and correct errors that could disrupt the project float.

I’ve been there, asking my team things like, “For our estimate, should we only consider vendor quotes, or do we wait for client approval for evaluation first?” Each project is unique, and it’s these detailed questions that clarify our plan and ensure our project float is real.

    • Know Your Project Inside and Out: Understanding why and how the activity is scheduled in your project isn’t just extra work. It’s essential for identifying and fixing schedule issues to make sure your project’s floats are real.

Remember, it’s the little questions and the deep understanding that keep your project float accurate.

3 – Refining Schedule for Accurate Project Floats

Your schedules run into a few problems with large project floats. Maybe you’re seeing some gaps in logic, or even negative floats.

Wondering if these can be fixed to make your project floats more accurate?

Absolutely! I’ll guide you through some straightforward tips to help you identify and refine your schedule, so you can track project floats like a pro.

Laying the Groundwork for Your Project Floats

First, make sure your work areas and crew sizes are well-defined if you’re working on field construction.

This step is important for getting a true picture of your project float. If you’ve got this covered, skip ahead! If not, here’s the thing:

You always need to factor in resource availability and site access right from the start.

Imagine you have two areas to work in, Piperack sections A and B. If both areas are easy to get to, you can have teams working in both at the same time, which helps you to get more float.

But if you can’t get into B, you’ll need to finish A before starting on B, which means you’ll have less float in your schedule.

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If your project is spread out over multiple locations, you’ll really need to think about your crew size and work areas.

Say you have 3 separate areas to work on, and they’re all quite far apart. If you have the resources, you could have 3 crews working on them all at once. This would give you more float in your schedule.

But what happens if you’ve only got two crews? Well, you’d work on 2 areas simultaneously. Then tackle the 3rd one after. This means a tighter schedule with lesser float.

Figuring out where your teams can be and when—really helps you understand how fast you can realistically get things done.

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Time to Fix Those Larger Floats?

  1. Find the Gaps: First, find the activity with broken logic (I will link this to filtering broken logic) (missing relationships) and link them as required for the project.

  2. Fix the Missing Links: Once you’ve found the missing links, if the list is long, it might be easier to export the tasks to Excel. This way, you can assign the correct relationships easily. For a short list, assign the links directly in P6. This approach will help you save time.

  3. Look at Large Floats: Watch out for floats that are really long, like 30 days or more in projects that last 2-3 years. When doubts, filter large floats (link to how to filter with large floats), and check the relationship to make sure the logics make sense.

  4. Get Team’s Input: After you’ve done the first pass, pull in your team for a fresh set of eyes and some expert advice to double-check your work.

  5. Double-check the Critical Path: Finally, take another look at your project’s critical path to fine-tune the project float. Then, review the critical path with your teams to validate. This will make sure the right activities are on the critical path.

〉 Tips on Tracing Logic Effectively:

While P6 has a trace logic feature, it can be a real drag.

A lot of planners I know skip it and opt for the ‘Relationships’ tags instead, and I personally prefer it.

The Relationship tag lets you see predecessor and successor activities all at once.


You can easily audit the logic to see what’s driving your project end date. Just add the predecessor and successor details for ‘Relationships’, Driving’, ‘Critical’ and Dates, etc.


〉 Watch Out for Overdoing It:

Remember, how you do anything shows how you do everything. So, try not to add links just to reduce your float—it can make things messy later.

If your team finds unnecessary links, it might look like you’re not sure of what you’re doing.

Solving Negative Floats in P6: A Practical Guide

Have you got negative floats in P6 schedule? That’s a problem. Why?

You can’t use it to manage the project or analyse schedule risks until you clear those negative floats.

A few years ago, working on a portfolio, I was stuck with negative floats across multiple projects with internal links. No matter what I tried, they wouldn’t go away. I wasted so much time.

I even experimented with changing milestone types, which sometimes worked but often didn’t.

It was frustrating, and I almost gave up. But I kept pushing through, and eventually, I found solutions that worked.

Here are the tips & tricks to help you deal with negative project floats in P6:

1 – Clear Negative Float in P6: Deal with Constraints

Often, negative floats in P6 are due to constraints. If you can, replace these constraints with predecessors.

But if you can’t and your project has hard constraints:

Find and check the Start and Finish constraints. Use the tips here to find constraints. (Negative Float Caused by the Constraints)
Make sure the constraint’s dates and times are not later than what you’ve planned.
If a constraint’s timing is off, adjust it to line up with your project’s forecast date, as calculated by P6. This small change can make a big difference.

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2 – Remove Negative Float in P6: Check Project Settings

If it’s not the constraints, check your project settings. Reason?
Sometimes, the ‘Must Finish By‘ date is the issue, especially if it’s from an older project template or set by someone else.

So, what’s the fix here?

Regularly check and update the ‘Must Finish By‘ date to match your current project’s targeted date. If you’re still seeing negative floats after this, there might be more to investigate.

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3 – Look at External Dates

If you’re still struggling with negative floats, consider external dates.

I often get feedback from planners saying – “I can’t find the reason why I got a negative float in the schedule”.

But when I asked if they had checked the external dates, most answered was “No”.

≠≠ Pick one of the options below for removing the negative floats:

    1. Remove external dates: Remove any external start or finish dates from your schedule that could be causing the negative floats. How?
      • First, filter tasks with ‘External Early Start’ and ‘External Late Finish’.

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      • Second, look for the activity columns External Early Start and External Late Finish. Then, delete it from your schedule.

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    1. Replace with soft constraints: If you need to keep these dates, try replacing them with more flexible constraints like ‘Start On or After’ or ‘Finish On or After’.
    2. Ignore External Dates: Alternatively, you can choose to ignore external dates completely by adjusting your schedule settings. How?Press F9 or go to Tools, Schedules, click on “Options, ” and select ‘Ignore relationships to and from other projects.’ This will clear the negative float from P6.

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  1. Managing Negative Floats in Multi-Project Environments

    If your project is part of a larger group of projects and you’re still getting negative project floats, here’s what you can do:
        1. Focus on Your Project Alone: Check the total float or critical path of just your project first, not the whole program. Solution? Ignore the links from other projects. This lets you evaluate your project’s float independently. You can set this in the schedule options under ‘Ignore relationships to and from other projects’.
        1. Evaluate Multiple Projects Together: If you’re overseeing several projects, you might need to look at how they all connect. Curious about how constraints or milestones from other projects are impacting your project? Here’s how you can check:
            1. (1) Open all the related projects and check their constraints and milestones first.
            1. (2) Open the activity columns for Primary Constrains and Primary Constraint Dates.


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            1. (3) And then filter for Start Constraint, then Finish Constraints.


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          1. Change Strict Constraints: If you find strict deadlines like ‘Finish On or Before’ in your projects, try changing them to more flexible ones like ‘Finish On or After’. This change will help you remove negative floats.
          2. Update Constraint Date: If you want to keep the deadlines like ‘Finish On or Before’, it should be the only hard constraint in your program. Then, update the constraint date to make sure that it’s before the forecast. Here’s what you can do:
            1. Clear Out Old Constraints: First, remove all the hard constraints. Then, run the schedule again by pressing (F9) with the longest path option.
              Then, P6 will tell you a new forecast date, say 20th Nov.
            1. Set the New Constraint: Next, change the constraint date to match this new date, 20th Nov, or pick a later date so it won’t cause a negative float.
              Re-run the schedule again by pressing (F9). Again, use the longest path option for this. The negative float should disappear from the schedule.

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  1. 4 – Watch Out for Multiple Calendars

    You’ve already worked on negative floats caused by deadlines and other constraints, but they’re still showing up. What’s the reason here?

    Your project might be using different calendars for milestones, like a monthly approval meeting calendar. And other tasks with a 5-day workweek or a 7-day calendar.

    Here’s how to handle it:

        1. Change the Activity Type: If you see a negative float, switch the activity type to ‘Start Milestone’.
        1. Make Adjustment: If that doesn’t solve it, change it to ‘Task Dependent’ and keep the duration to a day. This switch often fixes the negative float issue.


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    Pro Tip: Using multiple calendars can make finding the critical path tricky. Always choose the ‘Longest Path’, especially when multiple calendars are in use. Relying on project float to find the critical path may not give you accurate results.

    1. 5 – Eliminating Negative Float (Due to LOE Activity)

      Still dealing with negative float in your project, even after adjusting milestones, calendars, external links, and constraints?

      The issue might lie in your Level of Effort (LOE) activity setup.

      If the LOE activity’s logic or scheduling options are set up incorrectly, you could end up with negative float. The problem happens when Primavera P6 draws a hammock between two activities, even if there’s no predecessor. It’s easy to miss this if you’re caught up in scheduling, but setting up the wrong logic can quickly lead to a negative float headache.

      To avoid this, follow these tips:

        1. Include a Predecessor for LOE: Make sure each LOE activity is properly linked to a predecessor.

        • Here’s how you will find this in P6 – LOE activity with the predecessor.

        1. Use the Default Schedule Options: Don’t change the schedule option to “Start Float = Late Start – Early Start.” Instead, stick to the default Finish Float = Late Finish – Early Finish.

      Now, you know you can fine-tune the schedule like a pro: laying the groundwork that influences your project float, fixing the large float and negative float issues that can arise from many issues.

      But there’s more you can achieve by tracking the project float. Next, I will explain how you can leverage project float that benefits your project in a great way.

4 – Leverage Project Float for Schedule Optimisation

Some people will say the schedule development is done once they have assigned the logic and adjusted the schedule dates to align with project constraints. But you are not stopping here.

You want to look deeper and look for opportunities to improve your schedule. One way to do this is to leverage your project float. This will help you reduce project costs, maximise profit, balance the workload, and avoid unnecessary stress for the resource working on your project.

Use Your Project Float for Cost Reduction (Maximise Profits)

This is where your free floats are very handy. Why?

This is the amount of flexible time the activity has without impacting its successor activity.

In our schedule, brick procurement got 20 days of free float.

This task can delay for another 20 days without impacting its successor – ‘Brick Exterior Walls’. This is where you can use this opportunity for you.

For example, what if the brick supplier says it will be 25% off the price if you wait for 40 days lead time? This will help reduce the project cost while you still have 10 more days to cover the risk of procurement delay and also meet the project deadline.

Then, what do you do? Simply extend the duration of brick procurement to 40 days.

Here is another example – Doors and Windows work contractors say we need to work at the weekend as well to complete this work in 10 days, and they are currently busy elsewhere. The contractor says, ‘Can we delay to another week? We are only available to work on a weekday. This will reduce to 20% of the cost.

Then, what do you do this time?

Adjust the schedule to align with contractors’ availability. It means creating an activity calendar that matches with contractor’s availability and assigning it to the schedule.

Here’s the schedule after Optimising Schedule (for cost reduction while meeting project requirements).

Max Out Your Team Without the Burnout: Leveraging Project Float

Project float can help your team by balancing workloads, preventing stress, and saving money.

Use it well to show your team that you care about their workload and efficiency.

Here’s How to Use the Project Float Effectively to Optimise Resources:

After resource loading is done:

    • Spot Overloads: Find where your team is stretched too thin. This might be certain weeks where everyone is overloaded with work.
    • Adjust the Schedule: Use your project float smartly by rearranging tasks with project floats. This trick, known as resource levelling, helps spread the workload more evenly. P6 offers a quick fix with its resource levelling feature, but I prefer adjusting schedules manually. This way, I can watch each change as it happens. It’s a hands-on approach that lets you control the pacing and distribution of tasks directly.

Example of Resource Optimisation:

Let’s say you have a peak in weeks 5 and 6, where your mechanical team has got too much work.

Here’s a step-by-step fix:

    • Review Busy Periods: Notice the bottleneck during weeks 5 and 6? Three mechanical tasks with a lot of hours are happening at the same time.
    • Look for Project Floats: Find tasks with project floats but are causing resource peak.
    • Redistribute Work: Consider extending the duration of those tasks with resource issues. Or delaying them to even out the workload without causing project delay. By doing so, you make sure no week exceeds the 250-hour work limit.

For instance, by adjusting the schedule of some specific tasks, you manage to spread the work more evenly.

Here, I picked these activities: Piping hook-up with Heat Exchangers at Area – A and Piping hook-up with Pumps at Area – B. Why?

Both activities are in the change of activities where they have project floats.

This way, even with the adjustments, Area A ends up with a 1-week float and Area B with a total float 2-week, ensuring the project stays on track without overworking your team.

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Fine-tuning your resources is like unlocking a new level of project success.

With realistic project floats, you’ll have no trouble identifying those high-priority tasks.

And here’s where it gets even better: you’ll be tracking your project with a float status tracking process. This will ensure you’ll meet your deadlines without breaking a sweat. Trust me, your team will thank you for this.

5 – Keep Projects on Track with Float Status Tracking

You’ve nailed the schedule; now let’s make those project floats work for your project. It’s all about visibility and control right?

Without tracking the project float, you’re in the dark about how your project’s really doing. Here’s I will show how you can create schedule reports that make up float tracking system.

Excited? Let’s get into it!

1 – Issue the Top 3 Float Path Report

Why only the top 3 floats instead of, say, 20? Simple: It keeps you focused on what really impacts your deadline—the longest path and those close to becoming critical. This sharp focus helps you control the project more effectively.

Quick Tip: Get Top 3 Float Path Layout for P6. This tool lets you identify the paths that need your attention now versus what’s on track.

2 – Craft a Milestone Status Report That Track Project Floats

I’ve never met a project manager who isn’t interested in key dates on Milestone Status Report.

Why? Big picture, small details—this report has it all.

It’s your roadmap to informed decisions, blending key dates with external factors like Construction Work Completion by others.

This might impact your plan, and project floats if you don’t include milestones like that.

What are the action steps?

1– Apply the Right Filters:

Focus your schedule’s view on what really important. Now, go to the “Filter” menu. Bring in the “Milestone” and “Not Completed” filters. This combo helps you track which milestones are still remaining.

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2– Set Up Your Project Layout:

Even with the right filters, you can’t track milestone status without the correct layout. What’s the solution? Add these critical schedule data into your project layouts:

    1. Baseline Variance:
      To track schedule variances, add a column for variance baseline dates. Here’s how:
      • Go to View » Columns.
      • Choose “Duration”, then “Variance – BL Project Finish Date“.
      • Add that field to your view.

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    1. Last Update Variance:
      This compares schedule variance between current finish date and last update baseline. Use “Variance – BL1 Project Finish date” field.
    1. Project Float Data:
      Add BL Project Float and Total Float to see both Baseline Total Float and Current Total Float. By having these columns side by side, you can easily see if a task that once had a lot of float is now critical.Pro Tip: Assign the project baseline first. Without it, you won’t be able to find the BL Project Total Float column in P6.

    1. Highlight Milestone Variance:Adjust your Gantt chart to highlight milestone variances.
      • Go to “View“, then “Bars“.
      • Select “Baseline Milestone” and “Project Baseline Bar” for a visual cue on your milestones’ status.
        This setup relies on having a project baseline in place. It’s the foundation that makes your milestone tracking meaningful and actionable.

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3– Add Traffic Lights:

Get your project team’s attention by showing the red and amber traffic lights for the milestone that requires focus. How?

Run Global Change in P6.

This is a great feature of P6 that many people don’t know about. I’m serious.

A few weeks ago, an experienced planner on our team saw the schedule report I was working on, which had traffic lights indicating delays and potential issues. He asked how I did it, and I explained that I used global change to assign indicators for the traffic lights. He had been using P6 for 15 years and didn’t know this feature existed!

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Steps for using Global Change for traffic lights?

≠≠ Assign Red Flag for More than 2 Weeks Delay:

        1. Go to Tools » Global Change, then click New to create a new global change.
        2. In the IF section, add the parameter: ‘Variance – BL Project Finish Date’ is less than or equal to -10d.
        3. In the THEN section, add the parameter: ‘User indicator’ = Red.

≠≠ Assign Amber Flag for Less than 2 Weeks Delay:

        1. In the IF section, add the parameter: ‘Variance – BL Project Finish Date’ is within the range of -10d to -1d.
        2. In the THEN section, add the parameter: ‘User indicator’ = Yellow.A screenshot of a computer Description automatically generated

≠≠ Assign Green Flag for On-Track Activities:

        1. In the IF section, add the parameter: ‘Variance – BL Project Finish Date’ is greater than or equal to 0.
        2. In the THEN section, select the available indicator: ‘User indicator’ = Green.

Apply the Changes:

        1. Select the Global change 01 (Yellow), then click Apply Change.
        2. Repeat the same steps for the Red and Green global changes.

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Pro Tip: The milestone report is only as good as the data it’s based on. So, your milestones need to link with the relevant predecessor and successor activities. Otherwise, your milestone report won’t be useful for tracking project floats.

And make sure you have solid list of project milestones for a quality schedule that your team will love. If you need help, get your FREE Project Milestone Checklist.

3 – Launch a Lookahead Schedule with Project Floats

Why wait for a task to scream “urgent” before giving it attention? Your lookahead schedule with project floats is about proactive planning, showing what’s ahead and its urgency.

Deep Dive into Action Steps:

    1. Prepare Schedule Variance: Use the formula to track potential slippage or export the data straight out of scheduling software.
      Simple math is: 

        • Baseline Finish – Current Finish for Baseline Variance Finish.
        • Last Update Finish – Current Finish for Last Update Variance Finish.

How to get variance data in P6? Show the columns for Variance – BL Project Finish vs Variance – BL1 Project Finish.

    1. Showcase Float and Criticality: Keep the team alert to shifts in project floats and upcoming critical activities. For example, add the float variance data into your report. Use the formula for this: Baseline Total Float – Current Total Float.
    2. Add Traffic Lights for Visual: Get people’s attention by adding traffic lights to highlight the amount of the schedule variance and the project float status. Why? People wont take action until they see the traffic light on their name.

      Here’s example for Schedule Variance Traffic lights :
        • Red for schedule with more than 2 weeks delay.
        • Amber for less than 2 weeks delays.
        • Green for on track.

Hows’ about Traffic light for Current Total Float? Here’s what you could do:

        • Red for critical activities with total float less than and equal to 5 days.
        • Amber for nearly critical activities with total float less than and equal to 10 days.
        • Green for non-critical activities with total float more than 10 days.

Give them What they Want: Honestly, people don’t want to see fancy reports. But they want to know the priority tasks. So, give them what they want to see.

For example, add a filter ‘Criticality with Variance’. If a task is marked “Yes” for decreasing project float and schedule delay, it’s all hands-on deck. That’s our cue to prioritise and tackle head-on.

Here is criteria for Criticality with Variance – Yes: Current Total Float less than 10 days and 2 weeks delay from last update.

Now Go Out and Show Your team What You’re Made of

There’s no need to doubt yourself.

You don’t need to wonder if you can really make a difference.

But guess what? You can step up and lead. You’ve got five steps now that can change how you handle your projects.

Imagine this: you’re no longer just watching from the side; you’re guiding your team away from delays with confidence.

By mastering Project Float, you’re not just keeping track of schedules; you’re paving the way for success.

You’ve learned how to use Project Float to stay on track and meet deadlines. These skills will earn you respect from your team. They need a leader, and you can be that person.

So, take a deep breath, trust what you’ve learned, and step into your role with confidence.

You’ve got this. The road ahead might be tough, but with this guide, you’re ready to handle it. Go out there and show your team what you’re made of.

You’re ready to lead them to success.

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