Inflexible constraints require an associated date that controls the start or finish date of the task. These constraints are useful when you need to make your schedule take into account external factors, such as the availability of equipment or resources, deadlines, contract milestones, and start and finish dates.
This gives the scheduling engine the most flexibility in determining the ideal finish date for your project. To review or change the constraint on a task, right-click on the task, click Task Information , then click the Advanced tab. Constraint information is in the Constraint type and Constraint date boxes. If the constraint is anything other than ASAP or ALAP, the constraint type will display its associated graphical indicator in the Indicator column in any sheet view, such as the Gantt chart.
Constraints with moderate scheduling flexibility will restrict a task from starting or finishing before or after a date you choose. For example, a task with a Start No Earlier Than SNET constraint for June 15 and a finish-to-start dependency to another task can begin June 15 if its predecessor is finished by June 15 or later if its predecessor finishes after June 15 , but it can't be scheduled before June For example, this might be appropriate use of constraints if you have a building permit that is only good for a specific dates.
With the default finish-to-start task relationship and an ASAP constraint applied to these tasks, the successor task the second one is scheduled to begin as soon as the predecessor task the first one is scheduled to finish.
With a SNET constraint applied, the successor task cannot begin before the constraint date, even if as shown here the predecessor task is completed before the constraint date.
Schedules the task as late as possible with the task ending before the project ends and without delaying subsequent tasks. This is the default constraint for tasks when you schedule from the project finish date. Do not enter a task start or finish date with this constraint. Schedules the task to begin as early as possible. This is the default constraint for tasks when you schedule from the project start date.
Do not enter a start or finish date with this constraint. Schedules the task to start on or after a specified date. Use this constraint to ensure that a task does not start before a specified date. Schedules the task to finish on or after a specified date. Use this constraint to ensure that a task does not finish before a certain date. Schedules the task to start on or before a specified date. Use this constraint to ensure that a task does not start after a specified date.
Schedules the task to finish on or before a specified date. Use this constraint to ensure that a task does not finish after a certain date.
Schedules the task to finish on a specified date. Sets the early, scheduled, and late finish dates to the date that you type and anchors the task in the schedule. Schedules the task to start on a specified date. Sets the early, scheduled, and late start dates to the date that you type and anchors the task in the schedule. By default, all tasks in a project that is scheduled from the start date have the ASAP constraint applied.
Inflexible constraints usually override any task dependencies and restrict a task to a date you choose. For example, a task with a Must Start On MSO constraint for September 30 and a finish-to-start dependency to another task will always be scheduled for September 30 no matter whether its predecessor finishes early or late. You can change this behavior. Click File , click Options , click Schedule , then select the Tasks will always honor their constraint dates check box.
Task types apply only to automatically-scheduled tasks, and come in three flavors: fixed units, fixed work, and fixed duration. To change a task type, double click the task name in the Gantt chart, then click the Advanced tab. Let's say you have a fixed-units task, with 1 full-time resource unit available for 8 hours each day.
You set the task up with a day duration and 80 hours of work. If you find out that another full-time resource can assist on the task, Project recalculates the task's duration. The task now has two units assigned, with a 5-day duration and 80 hours of work.
If you find out that you have 8 days to complete the task rather than 10, Project recalculates the task's work. The task now has an 8-day duration, with 64 hours of work and 1 resource unit. If you find out that the task will take 20 hours of additional work, Project recalculates the task's duration. The task now has hours of work, with a duration of Now let's say you make the same task a fixed-work task.
This means that the task can take only the amount of work that you specify: no more, no less. In this example, the task has 1 full-time resource available for 8 hours each day, and it has a day duration with 80 hours of work. The task now has 2 units assigned, with a 5-day duration and 80 hours of work. If you find out that you have 8 days to complete the task rather than 10, Project recalculates the task's resource units. In order to get the task done in 80 hours over 8 days, 1.
Finally, let's say you make the same task a fixed-duration task. This means that the task must be completed in the duration that you specify. Again, in this example, the task has 1 full-time resource available for 8 hours each day, and it has a day duration with 80 hours of work.
If you find out that another resource can assist on the task, Project recalculates the work assigned to each resource. When just 1 resource was assigned to the task, that resource had 80 hours of work to complete. When you assign another resource to the task, each resource has 40 hours of work to complete over the same day duration, for a total of 80 hours of work.
If you find out that the task will take 20 hours of additional work, Project recalculates the task's resource units, so that the additional work can still be completed within the day duration. The task now has hours of work, with a duration of 10 days and 1.
Note: Because assignments of cost resources don't have values for work or units, these values will not be recalculated when the task's start date or finish date is modified. Dates also are never recalculated for a cost resource assignment, because you cannot modify the work or units. If you click Fixed Work in the Task type list, you cannot change the Effort driven setting for the task.
Fixed work tasks do not have flexible work values and are therefore always effort-driven. See more about effort-driven tasks later in this article. You can view and change the task type for each task directly in your view by inserting the Type field. Click the column to the right of where you want to insert the new column, click the Insert menu, and then click Column.
In the Field name list, click Type. If you want to change the hierarchical structure of a task or subtask as part of an outline structure for your project, you need to indent or outdent the task rather than change the task type or add a deadline date. If you want to impose restrictions on the way Project calculates the start and finish dates of tasks, you need to set a task constraint, rather than the task type. For all tasks, after you assign a resource, the task is scheduled according to this formula assuming tasks are the default fixed-units task type :.
For any task, you can choose which piece of the equation Project calculates by setting the task type. When you assign or remove people from a task, Project lengthens or shortens the duration of the task based on the number of resources that are assigned to it, but Project does not change the total work for the task. This is called effort-driven scheduling. This setting is usually turned off.
To turn it on, click File , click Options , click Schedule , then select the New tasks are effort-driven check box. Although effort-driven scheduling can work in most scenarios, you may want to change this behavior to more accurately reflect what happens on a particular task when resources are added or removed. For example, you may want to see the total work increase as you add more people to a particular task. Right-click a task, click Task Information , and then click the Advanced tab.
Note: You cannot remove effort-driven scheduling from fixed work tasks. Fixed work tasks do not have flexible work values, and are therefore always effort-driven. The effort-driven calculations apply only after the first resources are initially assigned to the task. After the first resources are assigned, the work value doesn't change as new resources are assigned to or removed from the same task.
If the assigned task type is Fixed Units , assigning additional resources shortens the duration of the task. If the assigned task type is Fixed Duration , assigning additional resources decreases the individual unit values for resources.
If the assigned task type is Fixed Work , assigning additional resources shortens the duration of the task. Knowing the differences between manually scheduled tasks and automatically scheduled tasks is key to understanding how Project schedules your project.
Generally, manually scheduled tasks put you in control of the schedule. When you add a task to your schedule, it stays put. Take a look at the picture below. It shows the two different types of tasks, the first two manually scheduled, and the last two automatic.
Note that for the manually scheduled tasks, the duration is a text value as well as a number. Since the duration can be a text value, a start date hasn't been set automatically by Project, and the Gantt bar is only partially displayed to reflect the uncertainty of the task schedule at this point. By definition, automatically-scheduled tasks with valid durations, start dates, and finish dates—and therefore, bars—are automatically drawn by Project.
Now, it gets a little tricky sometimes with the information you provide for manually scheduled tasks. All that is needed for Project to draw bars on a manually scheduled task are three time values: duration, start date, and finish date.
If you set two of these values for a manually scheduled task, the third value will be calculated by Project automatically, and the task will remain manually-scheduled. Note: Tasks are manually scheduled by default. Project managers who are accustomed to automatic scheduling with past versions of Project can turn the manual scheduling feature off for specific tasks or for the entire project.
Some projects, especially complicated ones, may require Project's powerful scheduling engine to take care of scheduling for you. To change all tasks to be automatically scheduled, click New Tasks: Automatically Schedule at the bottom of the Project application window. You can place a manually scheduled task anywhere in your schedule, and Project won't move it. This new feature gives you greater flexibility and control over planning and managing the schedule.
Why would you care? Well, at times project schedules are often very informal. They begin as simple lists of dates from e-mails, meeting with stakeholders, or a hallway conversation. Project managers very often do not have complete information on work items. For example, they may only be aware of when a task needs to be started, but not its duration until they have an estimate from their team members. Also, they may know how long a task will take, but they do not know it can be started until they have approval from the resource manager.
You'll never be left in the dark. Manually scheduled tasks have their own indicators and task bars to help you distinguish them from the "classic" automatically scheduled tasks.
Anything goes. When a task is in manually scheduled mode, the Start, Finish, and Duration columns can be blank or include text values in addition to recognizable dates. Switching scheduling modes You can change a task back and forth from manually scheduled to automatically scheduled. Be careful, though.
When you change a task from manually scheduled to automatically scheduled, Project is going to have to make some decisions.
If a task's duration was "A fortnight", Project usually sets an estimated duration of "1 day? Control slippage If a manually scheduled task has to be delayed due to a slippage, its successor tasks will not be automatically pushed out. Project managers can decide to keep the original dates if their resources are able to proceed as planned, or delay the successor tasks if there are hard dependencies. Effort-driven impacts Manually scheduled tasks cannot be set to effort-driven.
The duration of a manually scheduled task will not change as more resources are assigned to it, or removed from it.
Learn more about later in this article. The following table shows how Project attributes are defined and used for scheduling manually and automatically scheduled tasks. Can be number, date, or text information, such as "14d" or "fortnight". Not used by Project to help schedule the project if value is not in a recognizable format for duration. Can be assigned to tasks. Used by Project to Help determine best schedule.
Will change the duration of tasks if tasks are set to effort-driven, unlike manually scheduled tasks. Can be a number, date or text information, such as "Jan 30" or "Sometime soon. Only date information can be used. Can be a date or text information, such as "Jan 30" or "Sometime soon. Can be used, but won't change the scheduling of the task. However, task links will reschedule a task when first applied. Project and resource calendars.
Automatically scheduled tasks are the classic way Project schedules your tasks. Automatic scheduling provides a highly structured, systematic means of managing project schedules. If anything about your project changes after you create your schedule, you can update the tasks or resources and Project adjusts the schedule for you.
You can enter resources in your project and then assign them to tasks to indicate which resource is responsible for completing each assignment. Not only does this help you plan project staffing, it can also help you to calculate the number of machines needed or the quantity of material to be consumed.
If you enter resources, task schedules are further refined according to the following resource information:. Other elements, such as lead time and lag time for links, task types, resource availability, and the driving resource, can affect scheduling, so understanding the effects of these elements can help you to maintain and adjust your schedule as needed.
Note: Project calculates the duration of automatically scheduled tasks based on the definitions of the duration units Click File , click Options , then click Schedule. Just like a normal monthly calendar, the year begins in January and each week begins on Sunday or Monday. By default, when Project calculates duration units, one day equals 8 hours, one week equals 40 hours, and one month equals 20 working days.
If you enter start and finish dates for tasks and don't enter start and finish times, Project uses A. You can change a task's scheduling back and forth from automatic to manual click File , click Options , then click Schedule.
When you change task modes, keep the following in mind. A task that is changed to automatic scheduling will have duration and dates set to Project's default settings. For example, Project will change a manually scheduled task with a duration of "A couple weeks" to the default of "1 day? A task that is changed to manually scheduled will retain its duration and dates. However, after the task is set to manually scheduled, the duration and dates can be any number, text, or date value.
Float also known as slack helps you find those tasks that can budge without changing the end date of your project. You may want to view tasks that currently can slip without affecting the critical path total slack or those tasks that can slip before affecting the task that they are connected to free slack. While in the Gantt chart, click Format , then select the Slack check box. Float appears as a thin line attached to the end or beginning of Gantt bars.
Use the Detail Gantt view. It discusses how they relate to the scheduling equation when recalculating remaining task duration. Try the Project Course for Free! Try It Free! Task Types in Microsoft Project: Overview This lesson discusses how task types in Microsoft Project affect the scheduling formula used to calculate task duration. You can always change any value duration, units, work for a task , regardless of the task type.
In this blog, you will learn about duration, units and work in Microsoft Project Afterwards, we create a task but before assigning a resource to it, the task has the duration but no work is linked with it. Since the work represents the amount of an effort; a resource will be spent to complete a task. If you have one person, who is working full time, the amount of time measure as work is the same as the amount of time measured as duration.
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