Duration Correlations

Overview

Duration correlations make it possible to relate the sampling of durations between multiple activities.

Correlations are ONLY available between activities, not between hammocks, LOE's, WBS summaries, milestones, or benchmarks.

For example, if the duration of an activity is sampled at the upper end of its range:

You may want the duration of another activity to also be sampled at the upper end of its range (positive coefficient)
Or you may want the duration of another activity to be sampled at the lower end of its range (negative coefficient)
Duration correlations are defined using coefficients from -1 to 1.

Coefficient Behavior

Goal	Example	Coefficient
Strong	A sampled high, B sampled high	High positive, e.g. "1"
Weak	A sampled high, B sampled somewhat high	Low positive, e.g. ".25"
Weak inverse	A sampled high, B sampled somewhat low	Low negative, e.g. "-0.25"
Strong inverse	A sampled high, B sampled high	High negative, e.g. "-1"

Tip

Correlations can be defined in P6 and imported. For more info, see Mapping User Defined Fields.

Defining Correlations

Click the Ranging icon.
Select an activity from the upper list.
Click the View button above the bottom list and choose Duration and Cost.
Check the box in the Correlate column next to a desired activity in the lower list.
Adjust the value in the Coefficient column as necessary.

Required columns will display a Warning icon. If none of the required columns are visible, they must be turned on (see Customizing Columns). So long as any column contains a warning, the entire row will be colored red.

Tip

At any time, rows with warnings can be found by typing "error" or "warning" into the search box above the list.

Mutual Exclusivity Coefficient Warning

Any coefficient between -1 and 1 is technically valid; however, a single coefficient is always taken in consideration with every other coefficient during simulation. For this reason, it is possible that a single coefficient makes the entire set incalculable. Note, however, that this value by itself is not incorrect and could be accepted if other coefficients were modified. Take the following activities and their coefficients:

Correlation between	Coefficient	Order defined
A and B	1	1
B and C	1	2
C and A	-1	3

In this case, it is the correlation between C and A at "-1" which causes the entire set to be both positive and negative simultaneously and hence reset; however, if the order entered were 1 then 3 then 2, it is the correlation between B and C that would be invalid. Similarly, if the other coefficients were modified first to also be negative, then no error would arise.

In addition to positives and negative coefficients, correlations may become incalculable due only to the variance between coefficients themselves.

Copy/Paste/Fill Down

Once entered, correlations can be copied and pasted or filled down to save time. For details, see Interface Tour.

Available Table Columns

For details on customizing columns, filtering, sorting, and organizing by WBS, see Interface Tour.

Correlation Columns...

Column	Description
Abbr. Description	A NetPoint-unique field limited to 48 characters for describing the activity.
Calendar	The schedule that work on the activity can take place.
Codes	A submenu containing one column for every code in the schedule. The organization and visibility of code columns is NOT saved with the application. Code columns must be turned back on every time the tab is changed.
Coefficient	A value from -1 to 1 for specifying the degree of correlation.
Completed Duration	The amount of time already completed.
Constraint #1	The primary constraint, if any. The following abbreviations are used: ALAP (As Late As Possible), MEO (Finish On), MEOA (Finish On Or After), FNL (Finish On Or Before), MS (Mandatory Start), MF (Mandatory Finish), MSO (Start On), SNE (Start On Or After), and MEOB (Start On Or Before).
Constraint #2	The secondary constraint, if any. The following abbreviations are used: ALAP (As Late As Possible), MEO (Finish On), MEOA (Finish On Or After), FNL (Finish On Or Before), MS (Mandatory Start), MF (Mandatory Finish), MSO (Start On), SNE (Start On Or After), and MEOB (Start On Or Before).
Constraint Behavior	A toggle for controlling how constraints behaves during simulation (only enabled if an activity/milestone has a constraint). If an activity has two constraints and Maintain is chosen, both will be maintained unless one is triggered, in which case the second one will be ignored. ALAP constraints will never be maintained and this option disabled for activities with only ALAP constraints (if an ALAP and another constraint exist and Maintain is chosen, only the other constraint will be maintained).
Correlate	A checkbox for applying a correlation.
Description	The text field for describing the activity. This column cannot be removed from the table when organized by WBS.
Distribution Type	A shape for organizing a range of values (e.g. durations, impacts, etc.).
Drift	The amount of the time an activity may advance before advancing the project start.
Duration Correlations	A summary of activities that have been correlated by ID with the coefficient showing in parenthesis.
Early Finish	The date the activity completes when its drift is equal to zero.
Early Start	The date the activity begins when its drift is equal to zero.
Existence Probability	Duration ranging only. The percent of iterations an activity will occur. When it occurs, the activity's duration is sampled from its range. When it doesn't occur, its duration is zeroed out for that iteration.
Finish Date	The date the activity completes. If actualized, the date is appended with an asterisk ( * ).
Float	The amount of the time an activity may be delayed before delaying the project completion.
High %	A range value used when Trigen is chosen for the distribution type.
ID	The user-entered unique identifier.
Include	A checkbox for enabling or disabling the selected functionality. This column cannot be removed from the table when organized by WBS.
Lambda	A range value used when BetaPert is chosen for the distribution type.
Late Finish	The date the activity completes when its float is equal to zero.
Late Start	The date the activity begins when its float is equal to zero.
Likelihood	Floating only. The percent of iterations an activity’s float will be sampled from its range during floating and pacing.
Max	A range value used for the following distribution types: BetaPert, Triangular, Trigen, and Uniform.
Mean	A range value used for the following distribution types: Normal and Log-Normal.
Min	A range value used for the following distribution types: BetaPert, Triangular, Trigen, and Uniform.
Most Likely	A range value used for the following distribution types: Constant, BetaPert, Triangular, Trigen, and Uniform.
Planned Duration	The amount of time the activity takes to complete.
Remaining Duration	The total duration minus the amount of time already completed.
Resource Cost	The total cost of the activity, as calculated by resource assignments.
Risk Assignments	A summary of all risks and/or scenarios assigned by ID.
Sampling Behavior	Duration ranging only. The behavior for sampling of in-progress activities. For definitions and examples, see Duration Correlations above.
Sampling Values	A summary for displaying the distribution type plus any range inputs together in the same field.
Start Date	The date the activity begins. If actualized, the date is appended with an asterisk ( * ).
Std.Dev.	A range value used for the following distribution types: Normal and Log-Normal.
Threshold	Floating only. The ratio of an activity’s float in the iteration when it comes up for sampling to the activity’s deterministic float (used for pacing only).
Total Float	The float + drift.
Type	The type of object, e.g. activity, milestone, hammock, etc.
Unit	A toggle for ranging in days or % variance.
WBS Sequence	A value for sorting when organized by WBS.

Jump to:

Still Need Help?

Click the icon above or visit our support desk.

Submit a Ticket

Next Steps

Add risks to the risk register

Run a simulation