When you first create a project in Primavera P6, you’ll need to enter in some initial project information. For example, you’ll need to give your project a name, a unique ID, and choose an EPS layer to place it into. An important variable you’ll need to consider is when the project will start – otherwise known as the Project Start date. The project start date will be the first date for your project. This is when the project can begin. You’ll choose a project start date when creating the project – but you can always change this start date as needed. 

In this article, we will go over the importance of the project start date in Primavera P6. First, we’ll look at what it is and how it differs from the Data Date. Then, we’ll cover how to change the project start date after creating the project. The following examples are all from Primavera P6 Professional 23 – but these tools are available in all versions of Primavera P6. 

What is the Project Start Date?

The project start date is the date the project can begin. This will be the start date for the first activity within your project. For construction projects, the project start date will typically be the Contract Award date – rather than the date construction begins. All activities added to the project will be set to start at this date, until you add relationships or constraints. You can not add activities to start prior to the project start date. Again, this is the date from which all activities can begin.

Most project schedules allow the use of positive lag – but you should not overuse it. It’s a best practice to use lag on less than 5% of all activities in the schedule. This lag value should generally be a short duration – ideally, it should not exceed 14 days. As you’ll see shortly, it is hard to identify lag on the schedule. Lag is not easily apparent when looking at the Gantt Chart or activity dates. It’s generally a better practice to use an activity to represent the lag time instead. This will make the waiting period much more obviously apparent on both the table and the Gantt Chart. Additionally, everyone will now know exactly what the waiting period is for.

Project Start Date vs. Data Date

Along with the project start date, most scheduling programs will also allow you to set a Data Date (or Status Date, in Microsoft Project). During baseline development, the Data Date will typically be the same as the start date – but these dates are tracking two very different things. 

The Data Date is the up-to-date for the project. It is the date that you have updated the project up to when performing status updates. When working on a baseline, this date will match the Project Start Date – indicating that you have not updated the project yet. However, as you perform status updates, you will move the Data Date to the date you’re scheduling up to. For example, if I’m performing monthly updates and I just entered in all actual dates for January, I would set the Data Date to February 1st. Within the program, this is today’s date – or the up-to-date – for the schedule.

The reason for the Data Date is to show what work has completed, and what work you have left to do. Completed activities will display to the left of the Data Date, showing what you have done so far. To the right of the Data Date, you’ll see everything that you still need to do within the project.

It’s important to only move the Data Date during the status update process – as it will reschedule any activities that have not started or finished. You can not have planned activities to the left of the Data Date – only actualized activities. Any planned activities set to take place before the Data Date will push forward with it, calculating a new date for them to start and finish.

Again, the Data Date will match the project start date for your baseline project – but it should change over time. On the other hand, the project start date is not meant to change as frequently. However, you can change it if you made a mistake or if project parameters shift.

Changing the Project Start Date

You can change the project start date at any time – even after adding activities to the schedule. However, if you haven’t actualized the activities, changing the project start date will change when the first activity in your schedule will start.

To change the project start date, navigate to the Projects screen by selecting Enterprise > Projects. Select the desired project from the list and select the Dates tab in the Project Details section. Under Project Planned Start, select the ellipses button to choose a new date. 

While on this page, it’s a good idea to also adjust the Data Date field to match. You can always do this while scheduling the project as well. The project schedule won’t actually adjust dates until you change the Data Date to match the new project start date.

After scheduling the project, your first activity will shift to start on the new project start date. All other activities will waterfall down from this set date.

Summary

In Primavera P6, the project start date is the date in which the project can begin. This is the first date in your project – typically, the Contract Award date. All activities you add to the project will schedule from this date forward. Typically, you’ll select a project start date when first creating the project. However, if you make a mistake, or if project parameters change, you can adjust the project start date at any time. You can adjust both the project start date and the Data Date using the Dates tab in the Details section of the Projects screen. You will need to change both of these dates and schedule the project to see the changes in your schedule. After adjusting the project start date, your first activity will shift to start on that date – moving the successor activities along with it.

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Lauren Hecker is an Primavera P6, Oracle Primavera Cloud, and Microsoft Project instructor. She teaches both onsite and virtual training courses. To see her next open enrollment course, please visit our calendar. To schedule an onsite or private training, please contact us!