On the SAP Easy Access screen, choose  Advanced Planning and Optimization Master Data Master Data for Maintenance and Service Planning Maintenance Task List .

Open the required task list and double-click on the task list node.

On the Activities tab, choose Network Graphic , select the line connecting the first two activities for which you want to change the relationship and choose Delete Object Relationship .

The line connecting the two activities is deleted.

Repeat the previous step for the other activities for which you want to change the relationship.

Choose Create Object Relationship , select the right-hand side of the activity you wish to place first in the relationship, and drag the cursor to the left-hand side of the activity you wish to place second.

Repeat the previous step for the other activities for which you want to change the relationship.

Choose Rearrange Horizontally to place the activities in the correct sequence.

Choose Close Network Graphic to return to the Activities tab.