Blog

You are here: Home / Blog

Dec

Weird Negative Float Situations – Part 1

Categories: Level of Effort, Primavera P6, Schedule Options

Tags: Level of Effort, negative float, Primavera P6, schedule options

Comments Off

by Bill Pepoon

Most of us understand that negative float is generated by a constraint that is not being “satisfied” and indeed, we cannot have negative float without a constraint. Or so it would seem. But during a recent training session at the Kennedy Space Center my client showed me several Level of Effort activities that had negative float. In fact, all of the Level of Efforts had negative float yet no other activity showed any negative float whatsoever. Imagine that; the activities linked to the Level of Efforts have positive float but the Level of Efforts have negative float!

In the first figure I am showing a typical setup with a Level of Effort activity linked to one predecessor and one successor. The Activity Type is shown in the Activity Table to make it easier to see which activity is the Level of Effort:

Okay, so far nothing is amiss. The Level of Effort is linked to activities on the critical path and therefore shares the same zero (0) float. But watch what happens when the predecessor to the Level of Effort is updated with progress:

The Level of Effort activity – and only the Level of Effort – has negative float! Keep in mind that no constraints are being used in this schedule. And while all of the Task Dependent activities are on the critical path I can assure you this has nothing to do with the negative float on the Level of Effort activity.

So how is this possible?

The answer has to do with the ability in Primavera P6 to calculate float three (3) different ways. These settings appear under Schedule Options:

I typically calculate float as the difference between the Late Finish and the Early Finish dates. But my client had selected Late Start – Early Start. (The third option is to take the smallest value of the two calculations). Choosing any setting other than Late Finish – Early Finish will generate negative float once the predecessor to the Level of Effort has started. Moreover, astute viewers will notice that the negative float matches the number of days that have elapsed since the predecessor started. The predecessor started five work days before the Data Date and the float is -5 work days.

Why this is happening is a little hard to explain, but Primavera P6 calculates float for both the start and finish of every task. Normally this results in the same value. Level of Effort activities, however, are another matter. Primavera P6 calculates the float on this type of activity as the difference between the Actual Start Date and the Data Date and perceives the activity as being “late” because the Data Date is later than the Actual Start Date.

Thankfully this weird float issue can be easily avoided by using Late Finish – Early Finish for the float calculations. And while this has always been my personal preference I have a whole new appreciation of this setting now.

Nov

The Significance of the “Default” Project in P6

Categories: Default Project, Primavera P6, Schedule Options

Comments Off

by Bill Pepoon

You might have noticed that Primavera P6 has something called “Set Project Default” under the Project menu. This is a very important consideration when multiple projects are open. To review, more than one project can be opened at the same time by highlighting them together and then right-clicking or using the keyboard shortcut Ctrl+O, as seen below:

There are several reason why we might want to open more than one project at a time. For example, we might be checking the logic on similar projects for consistency. Or we might be updating several projects on the same day and having them open together simply makes it easier to go back and forth. Activities in different projects can also be linked together by opening them together and adding relationships.

Next, we need to open the Project menu and select Set Default Project:

Then we select which of the open projects should be the default:

Setting a default project accomplishes several things:

Whenever this group of projects is opened in the future, the default project remains the same
New activities added to this group of projects will automatically be assigned to the default project (unless grouped by WBS)
Schedule Options for all open projects are determined by the default project

As an experiment, try grouping multiple projects in the Activities window by Project. If you try to add an activity to any project other than the default project the activity will still land under the default project. This could be problematic of course so it is good to know that grouping by WBS allows you to insert a new activity into any of the open projects.

Schedule Options is the most critical consideration. Casual P6 users often fail to consider that the Schedule Options for a project are unique. That is to say, Schedule Options do not apply to all projects. In the following screenshot we can see these options:

One of the open projects may have critical activities defined as the Longest Path while another uses Total Float to define critical. Regardless of the individual project settings only the default project’s settings will apply when the projects are scheduled together. And this brings us to the most important reason for setting a default project. As a scheduling manager you might be worried that not all of your schedulers are using the proper settings for calculating their schedules. For example, I have never used Progress Override because it distorts the logic (more on this in another post). The scheduling manager can open all the projects at the same time and schedule them knowing that all projects will be calculated in the same fashion.

Now, you may be wondering about the data dates of the open projects. What happens when they are not the same date? As soon as you try to schedule the open projects you will see this message:

In P6 Web (a component of P6 EPPM) it is possible to force all open projects to calculate to the same data date. But in P6 Professional this is not possible, and is often not desirable. But the ability to make sure than all open projects are being scheduled in a consistent manner is the key. The scheduling manager only needs to check the settings for the default project and can ignore what might have been done on the individual projects. Using the wrong settings, or not fully understanding what settings were used, is a common mistake that can be easily avoided with a default project.

Oct

P6 EPPM Training Available Online and In-Person Anywhere

Categories: In-Person P6 Training, Live Online P6 Training, P6 EPPM, P6 Optional Client, P6 Web

Comments Off

by Bill Pepoon

Earlier this year we rolled out our popular P6 101 (8-hour) and P6 102 (16-hour) training programs for P6 EPPM. We waited to offer this training until we had a chance to develop our own training materials. Our training programs are designed to mimic the steps necessary to create a schedule, run production, update and monitor progress, in that order. More importantly, we teach P6 EPPM from the perspective of professional schedulers who have been using Primavera software for 25 years. Some features in P6 EPPM are not appropriate for every industry. And there are situations where switching to P6 Optional Client makes more sense than trying to muddle by with P6 Web. Both of these components are included with P6 EPPM.

For example, you cannot automatically renumber Activity IDs in P6 Web while this can be accomplished quite easily in P6 Optional Client. So in the P6 EPPM environment an employee using P6 Web might need to request that another employee using P6 Optional Client perform this task instead. Conversely, the P6 Optional Client user would need to request that the P6 Web user change the Earned Value settings, one of many administrative settings that are only accessible via P6 Web.

Our P6 EPPM training programs are intended to teach the P6 Web component since P6 Optional Client is virtually identical to P6 Professional. However, we can teach both P6 Optional Client and P6 Web back to back in order to fulfill all of our clients’ training needs. We did this recently for a major Department of Defense contractor in Kansas City. The first two days were devoted to using P6 Optional Client and the next two days focused on P6 Web.

Already our P6 EPPM training has been in high demand. We recently completed a 6-week assignment for the State of California, developing training materials and training the in-house trainers. Ironically, we beat out Oracle itself for this assignment! Next week we begin training a major highway contractor in Texas. We provide P6 EPPM training online every month for individuals and groups. In-person P6 EPPM training is available anywhere in the world for small groups. Well, we only provide this training in English but otherwise no restrictions!

Below is an introduction to P6 EPPM that we recently posted on YouTube:

http://youtu.be/-so7qEzQ08o

This video explains how to set up a new project in P6 EPPM. In the next few weeks we will be posting more videos explaining various features of P6 EPPM. Please contact us if you have any questions.

Sep

P6 EPPM vs. P6 Professional

Categories: P6 EPPM, P6 Professional

Comments Off

by Bill Pepoon

Yesterday I delivered a P6 training session to a client who bought the enterprise (EPPM) version of this software for the wrong reason. There is a perception based on rather confusing marketing materials put together by Oracle that if you want to log in remotely to a database you must buy P6 EPPM. Nothing could be farther from the truth. But anyone who tries to muddle their way through Oracle’s website would have a hard time figuring this out.

P6 EPPM is web-enabled software. Notice I did not say “cloud” software. There is a big difference. When you buy P6 EPPM you still install it on a server in your offices. Once installed on a server, users access P6 EPPM using their Web browser. More on that in just a moment.

Deploying P6 EPPM in a large organization can certainly have benefits. Rather than installing P6 software on hundreds of computers you install it once. That is a pretty good deal and nearly as practical as true “cloud” software hosted on someone else’s servers. One of my clients has several hundred named users – meaning people who have access to the software – and not surprisingly they are using P6 EPPM.

So what about remote access using P6 Professional? Well, it’s not too difficult for anyone to gain remote access to a database regardless of which version of P6 they are using. You simply install the database on a server and users connect to it remotely using a Virtual Private Network (VPN) or some similar means of networking. Admittedly I know nothing about setting up a VPN but this is easy for an IT person to do. And most companies already have something like this in place already.

Because P6 EPPM is web-enabled, however, you are accessing files on the Internet. Lose your Internet connection and you are not getting any work done. With P6 Professional, you can install one database on your laptop and another on a regular server. This way you always have access to a database. Another advantage with P6 Professional is that using a Web browser is much slower than using software that resides on a computer. Each time you leave one window in P6 EPPM you are waiting for your browser to load another one. Unless you have a very fast Internet connection this will drive you a little crazy.

The Web browser introduces still another problem. P6 EPPM will not function correctly unless you are using Internet Explorer 8. Love Google Chrome? Too bad, because it will not work with P6 EPPM. And forget about using Mozilla Firefox as well. And frankly, who is still using IE 8 other than maybe Al Gore? Okay, that was a cheap shot at the guy who once claimed to have invented the Internet, but the point is most of us have already upgraded to something else – a long, long time ago.

Java also rears its ugly head in P6 EPPM, which requires a very specific version of Java that is several years old. Java is a programming language used by many applications and websites. Ironically, Oracle owns Java but P6 EPPM has to make do with a really old version. My client with the hundreds of named users quickly discovered that it had several different versions of Java installed on various machines. And during my class yesterday I could not get the Project Preferences pop-up window to appear no matter what I tried. Cursed Java strikes again!

(To be fair, P6 Professional also uses Java but because you are using the program in a standalone environment the older version of Java is not much of an issue).

So have I convinced you to switch to P6 EPPM yet? Look, P6 EPPM is fine for large organizations since it makes deployment much easier. But when I show people P6 Professional side-by-side with P6 EPPM, they always pick P6 Professional. If you have only a few named users, P6 Professional is easy to deploy. You might only need to install P6 EPPM once, but the last time I installed it required an entire weekend and several phone calls to Oracle Support.

When it comes down to scheduling projects – which is the point, after all – P6 Professional is easier to use, and much faster. But not to worry. P6 EPPM software includes P6 Optional Client in addition to the Web-enabled software, and P6 Optional Client is basically P6 Professional with just a few minor differences. Yet many people who purchase P6 EPPM are not even aware that another version of the program is included. Oracle simply does not explain this very well at all, but now you know!

Sep

Calendar Issues in Primavera P6

Categories: P6 Calendars, Primavera P6

Comments Off

by Bill Pepoon

Most Primavera P6 users are familiar with setting up and modifying calendars. There is a potential problem, however, when specifying more than 8 hours per day for activities. P6 defaults to 8-hour work days, as we will see in a moment, and interprets anything more than 8 hours as overtime. This results in activity dates not calculating as expected. In the following example, I created a 5-day calendar with 10 hours per work day, Monday through Friday. The work day starts at 7:00 am and ends at 5:00 pm (this allows for no lunch break but my theoretical crew is a bunch of really hard workers!). I assigned this calendar to an activity with a 5-day duration. Notice what happens:

The 5-day task finishes in 4 days. Why? Because P6 assigned an imaginary budget of 40 hours to my task based on a normal 8-hour day. By working 10 hours per day, my crew worked 40 hours in 4 days. This can be confirmed by adding a labor resource and watching what happens to the budgeted hours. While this figure can be changed later on, the initial budget will be based on 8 hours per day regardless of the calendar settings.

Now, savvy P6 users know that the hours per day can also be modified somewhere other than in the calendars. Under Admin, Admin Preferences, Time Periods, the hours per day, week, month and year can be specified. This menu is shown below:

We can change the time units under Admin Preferences to show 10 hours per day. This solves the problem of P6 thinking that anything in excess of 8 hours per day is overtime, but it also changes the settings of every schedule in the database. These are Admin Preferences, and not User Preferences. Admin Preferences affect all projects.

Nevertheless, we are real close to a solution. Note that right under the time periods in the Admin Preferences there is a box with the following phrase:

“Use assigned calendar to specify the number of work hours for each time period.”

Checking this box is real important because it allows us to use the hours per day in our calendars rather than the global hours per day under Admin Preferences. But we need to make one last adjustment.

Under Enterprise, Calendars, there is an option to specify time periods. These time periods are calendar-specific. In the screenshot below we can see the time period settings for just one calendar:

By making the hours per day in the time periods for this calendar match the hours per day in the calendar itself then P6 will properly understand what is considered to be a normal work day.

Your thoughts? Please email me with any comments or questions.

Aug

P6 Baselines Explained Once and For All

Categories: Primavera P6, Primavera P6 Baselines

Comments Off

by Bill Pepoon

In our experience as trainers, no subject causes more confusion in Primavera P6 than baselines. Inexperienced Primavera P6 users often believe they have a baseline when in fact they have never created one, or the baseline bars just do not look right. Even something as obscure (for many users) as Earned Value affects baselines. Because this is a fairly difficult topic, we have prepared a YouTube video that shows the proper way to create baselines in Primavera P6. Enjoy!