Understand and manage duration types and task constraints

In this video, you will learn the following things about duration types and task constraints:

  • What they are and how they work
  • Common mistakes project managers make with them
  • How to view all of them in your project
  • How to know when they need to be fixed
  • How to fix them
  • Best practices for using them
Have you ever created a project plan in a spreadsheet or on a whiteboard by writing a plan start date and a plan due date for each task? Then, when you need to change one task due date, you have to manually update all the start and due dates for each task after it in the timeline. This was one-way project for Manage before Workfront was available. But now you have Workfront, and in order for it to help you plan and manage a project, it has to know lots of things about what you’re planning to do. Workfront uses duration types and task constraints to let you indicate your desires of how tasks should be scheduled in your project timeline. Then it calculates the start and end dates of all the tasks in your plan and of your project as a whole. What a great thing! But wouldn’t it be nice to be able to see the duration types and the task constraints for each task to make sure they were what you thought they should be? Here’s a handy view called Duration Types and Task Constraints View. It shows you the duration type, duration, plan duration, task constraint, and the constraint date for each task. This view does not come built in with Workfront, so you’ll need to create it as a custom view. Don’t worry, step-by-step instructions are included in the Create a Basic View tutorial as one of the activities. There’s a link to it in the tutorial after this video. I’ll use this view to show you how duration types and task constraints work, how they can accidentally be changed, and how you can find and fix problems. First, we’ll talk about duration types. There are four duration types to choose from. When you create a new task, it will be given the duration type your system or group administrator has chosen to be the default. In this case, the default is a simple duration type. This is probably the most commonly used duration type. When you assign a single user, you can control the duration and the planned hours independently. So you can give someone four days to complete a task that you think will take them 10 hours. When you assign multiple users to the task, it will still take four days and 10 hours, but you can control how the planned hours are divided up. You’ll need to edit the task to do this.
Another common duration type is calculated assignment. When you assign a single user, you control the duration and the planned hours independently, just like with the simple duration type. When you assign multiple resources, it divides up the work equally between them. But when you edit the task, you’ll see that you can change the planned hours, but you can’t change the allocation percentage. It’s always going to be equally divided.
Calculated work is a duration type designed for activities like meetings. You can add more people to the meeting, but the duration of the meeting will still be two hours. However, the total planned hours will be calculated as the number of people assigned times the duration. With this duration type, you can edit the allocation, though. So if someone can only attend one hour of the meeting, you can change them to 50% allocated, and the total planned hours are recalculated to reflect that. Effort-driven is designed for tasks where you can add more people to the job to get it done faster, like peeling potatoes or filing a huge stack of papers. The more people you assign to this task, the less duration it will take to get the job done, while the planned hours remain the same. You might have been wondering what’s the difference between the duration and the planned duration. Well, this is it. Plan duration is always the same as duration, except when you’re using the effort-driven duration type, and you have more than one resource assigned. You’re also able to edit the allocation of a resource. It won’t change the duration or planned hours, but it will change the planned duration.
Now let’s look at task constraints. The most common task constraint is as soon as possible. This is the default for projects where schedule mode is set to start date. It means you want this task to have a start date which is as soon as it can be based on other factors, like the completion date of a predecessor task. See how task 7 has a predecessor of task 6. So Workfront calculates the planned start date of task 7 as immediately following the planned completion date of task 6. But what if we change the planned start date of task 7? For some reason we decide this task must start on April 21st. Notice how the task constraint changes to must start on with the constraint date of April 21st. We could have changed the task constraint ourselves, but Workfront does it automatically when we select a start date. As soon as possible is no longer what we want since we forced a start date. And what about the predecessor? It is now overridden by the task constraint, so the predecessor is ignored. It still appears in the task and will become active again if the task constraint is changed to something like as soon as possible or as late as possible. Let’s look at as late as possible now. As you can see, task 7 is planned to start on April 13th when the task constraint is as soon as possible. But it could start as late as April 26th when the task constraint is changed to as late as possible. Notice that the project planned completion date is still May 3rd, whether task 7’s task constraint is as soon as possible or as late as possible. We may want to run our project based on a completion date rather than a start date. We can do this by changing the schedule mode to completion date. But watch what happens when I add a new task to the project. The default task constraint for a new task is now as late as possible. That’s the default when schedule mode is set to completion date. Without realizing it, you could have a mix of tasks with as soon as possible and as late as possible in the same project. If you’re only looking at the planned start date and completion dates of your tasks, that may look confusing. The duration types and task constraints view can really help in cases like this. Depending on your project and what you really want, you might even want to change all of your task constraints to match the schedule mode. You can do this with a bulk edit. Whether you’re scheduling from a start date or a completion date, you may still want to choose other task constraints. Fixed dates is useful when you know exactly what the start and due dates need to be for a task. This way you can set both dates and Workfront will calculate the duration for you. Must start on forces of start date as we’ve seen and must finish on forces of due date. earliest available time, latest available time, start no later than, start no earlier than, finish no later than, and finish no earlier than. They’re all fairly self-explanatory and available if you want to use them. Consult the documentation articles linked in the tutorial for all the details. Best practice is for you to keep things as simple as you can and check on your duration types and task constraints to make sure they reflect what you want for your project.

For information on how to create a Duration types and task constraints view, see the Duration types and task constraints view activity in Create a basic view.

For details about duration types see Task Duration and Duration Types.

For details about task constraints see Task Constraints.