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How to Solve Out of Sequence Activities

Amr M. Morsy, Consolidated Contractors Company, March 2017

When you build a baseline programme for a project, the Activities relations used to build that

baseline are classified into types, hard and soft logic. Hard logic means that the relation is a fact

that is inevitable to happen such as Installation of the block works cannot finish before finishing

the Concrete Skeleton, or closing the false ceiling cannot be done before finish all the MEP

works under that ceiling. Soft logic means that the relation is used to achieve planned sequence

by the Contractor, and changing that sequence is applicable. Usually the actual sequence that

occurs on site differs from the planned sequence. So, when the baseline for the project is

updated after achieving actual progress on site and reflecting that in the update, out of

sequence activities show up.

There are different cases for out of sequence activities as illustrated below:

1- Successor Activity is started while the Predecessor Activity is already started but is not

completed yet, and the relation type between them is (FS)

2- Successor Activity is started while the Predecessor Activity didn’t start yet, and the relation

type between them is (FS) or (SS)

3- Successor Activity is completed while the Predecessor Activity is already started but is not

completed yet, and the relation type between them is (FS) or (FF)

4- Successor Activity is completed while the Predecessor Activity didn’t start yet, and the

relation type between them is (FS), (FF) or (SS)

To solve the out of sequence you need to modify the relationship type as follows:

1- In the 1st case you can modify the relationship type to be (SS) or (FF), but in this case also it

is better to make it (SS) to avoid having the activities out of sequence again

2- In the 2nd case you can modify the relationship type to be (FF) only

3- In the 3rd case you can modify the relationship type to be (SS) only

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4- In the last case, modifying the relationship type will not be helpful, and that means that the

out of sequence in that relationship may be result from improper update for the Project

Activities or that this relationship is already invalid relationship

Modifying the relationship type for each out of sequence relationship manually in Primavera P6

may consume a lot of time especially if those out of sequence activities number is huge. So, to

solve that issue, exporting Excel file from Primavera P6 will be more helpful and quicker.

The following steps show how to use Excel files to solve the out of sequence:

1- Export the Excel file of Activity Relationships from Primavera P6 using the template shown in

Figure 1

Figure 1

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2- Open the exported Excel file and use Excel filters as shown in Figure 2

Figure 2

3- To apply the solution of the 1st case, select “In Progress” in the “Predecessor Activity

Status”, select “In Progress” in the “Successor Activity Status” and unselect the “SS” in the

“Relationship Type” (as it is logical) as shown in Figure 2

4- Copy the Activity Relationships that resulted from the applied filters to duplicate them. Then

insert the letter “d” under the column “Delete This Row” for the copied Activity

Relationships and that step is used to remove the out of the sequence Relationships as

shown in Figure 3

5- To replace the removed Relationships change the “Relationship Type” for Activity

Relationships that resulted earlier from the applied filters to be “SS”

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Figure 3

6- In the 2nd case, select “Not Started” in the “Predecessor Activity Status”, select “In Progress”

in the “Successor Activity Status” and unselect the “FF” in the “Relationship Type”

7- Repeat the same steps as we did in the 1st case and change the “Relationship Type” for the

filtered relations to be “FF”

8- In the 3rd case, select “In Progress” in the “Predecessor Activity Status”, select “Completed”

in the “Successor Activity Status” and unselect the “SS” in the “Relationship Type”

9- Repeat the same steps as we did in the 1st case and change the “Relationship Type” for the

filtered relations to be “SS”

Using Excel files exported from Primavera P6 can save a lot of time and effort in solving the out

of sequence activities. So, it is better to have the knowledge of how to use benefit from the

features provided from Oracle to use link Primavera P6 with the Excel.