• In the Activities window, Top Layout, highlight an activity.
• In the Activities window, Bottom Layout, select the Codes tab. See Figure 5-2.
• Click the Assign button to open the Assign Activity Codes dialog box.
• The activity codes are grouped, with the code values listed below them.
Figure 5-2 Activity Window, Bottom Layout, Codes Tab
• To expand the view, simply click the + sign or double-click the activity code bar. By expanding the view on the activity code, its code values can be seen.
• Assign a specific code value by either double clicking on the code value or by highlighting the code value and clicking the
(Assign) button.
• By following this method, activity code values can be assigned to each newly created activity.
Figure 5-3 Activity Window, Bottom Layout, Relationships Tab
Relationships
In order to add, edit, or delete relationships to activities within the project schedule, click on the Relationships tab in the Bottom Layout, Figure 5-3. On the left side of the Relationships layout is the Predecessors window, and on the right side is the Successors window. Within either window is the Assign button. Clicking the Assign button under Predecessors will allow the user to assign predecessor activities, while clicking the Assign button under Successors will allow the user to assign successor activities.
The process for adding successors or predecessors is the same. For the purposes of illustration, a successor relationship will be added.
• In the Activities window, Top Layout, highlight an activity.
• In the Activities window, Bottom Layout, select the Relationships tab.
• Click the Assign button to open the Assign Successors dialog box.
• Navigate through the Assign Successors dialog box to find the activity to be added or use the Search function to find an activity directly.
• Add the located successor activity to the current activity by double-clicking on the successor activity, or by selecting it and clicking the (Assign) button.
• The newly assigned successor activity will show in the Bottom Layout.
• The default relationship type of a successor or predecessor is finish-to-start.
• If the desired relationship type is other than finish-to-start, then the relationship type must be change.
• Click on the pull-down button in the Relationship Type column.
• Select the desired relationship type by clicking on it.
Lags
A lag, the delay between the start or finish of one activity and the start or finish of another, can be specified between activities. There are many uses for lags, and some uses are not generally acceptable.
Lags can be positive or negative.
To add, delete or edit lags:
• In the Activities window, Top Layout, highlight an activity.
• In the Activities window, Bottom Layout, select the Relationships tab.
• Click on the Lag field under the Lag column.
• Click inside this field and type the duration of the lag in work days.
Constraints
P6 provides nine constraint types for early start or early finish dates when it becomes necessary to impose restrictions on activities to meet external requirements.
Start On or After—sets the earliest date an activity can begin. It forces the earliest start date to the constraint date; however, if the calculated start date is after the constraint, the later date will apply.
Start On or Before—places a deadline on the start of an activity.
It forces the activity to start no later than the constraint date.
Start On—forces the activity to start on the constraint date, regardless of calculations of the schedule; overriding schedule logic entirely.
Mandatory Start—forces early and late dates to be equal to the constraint date, regardless of schedule calculations.
Finish On or After—sets the earliest date an activity can complete.
Finish On or Before—places a deadline on the completion of an activity, forcing the activity to complete no later than the constraint date.
Expected Finish Date—is used as a means to predict a completion date other than the one calculated by the schedule.
Mandatory Finish—forces early and late dates to be equal to the constraint date, regardless of schedule calculations.
As Late As Possible—consumes the free float in an activity, and pushes an activity as late as it can be worked without impacting the start of the next activity.
To add a constraint:
• In the Activities window, Top Layout, highlight an activity.
• In the Activities window, Bottom Layout, select the Status
• Constraints are located in the lower center portion of the tab.
Status tab, Figure 5-4.
• To add a primary constraint click on the pull-down menu next to Primary.
• Scroll down to review the constraint types.
Figure 5-4 Activity Window, Bottom Layout, Status Tab
• Select the desired constraint by clicking on it.
• Next, click on the expand button by Date to open a calendar, within which to select a constraint date.
• Navigating within the calendar, select the desired constraint date.
• Highlight that date by clicking on it.
• Click Select.
Duration type determines how remaining duration, units, and units per time will be calculated when activities are updated that has resources assigned. The activity’s duration type should correspond to the factor that is least flexible in the project: schedule, costs, work effort, or resource availability.
Fixed Units/Time—used when resource availability is a limiting factor. In other words, it is used when the activity has fixed resources with fixed productivity output per time period.
When the activity duration or units are changed, resource units per time remain constant. This duration type is typically used for resource dependent activities.
Fixed Units—used when the units (defined as either costs or work effort) are a fixed and limiting factor, and increasing resources can decrease the duration. For these activities, if the user updates the duration or units per time, the units remain constant.
Fixed Duration and Units/Time or Fixed Duration and Units—
used when the user intends on holding the duration constant, because time is the limiting factor. These duration types are typically used for task dependent activities, which are activities whose duration remains constant regardless of the number of resources assigned.
▫ Fixed Duration and Units/Time activities are used when the duration and the resources (represented by units per time) remain fixed as units are changed, indicating that the scope of work will vary in order to allow a fixed crew size to perform work within a fixed time frame.
▫ Fixed Duration and Units are used when resources are variable. In other words, the duration remains fixed along with the units, but the crew size increases or decreases in order to complete the fixed scope of work within a fixed time frame. This is most common duration type for Caltrans.
Durations
To view and edit the duration type assigned to an activity:
• In the Activities window, Top Layout, highlight an activity.
• In the Activities window, Bottom Layout, select the General tab, Figure 5-1.
• Click on the pull-down menu for Duration Type.
• Highlight and click on the desired duration type to set it for that activity.
Each activity can have its own duration type. Therefore, each activity will calculate differently, depending on its settings.
Different settings could result in different results when the schedule is calculated.