Does Activities needs to have a successor and a predecessor

[Former Member]

If a project is set-up as backward scheduling, can I have activities without a predecessor?

I have tested and I am still getting correct dates but was adviced that for the project to correctly be scheduled I need to have all my activities with predecessor and successor except the two at the end.

[former_member183879]

Hi Deana,

You can very well have activities without predecessor and have only successor. You can have multiple such activities. All these activities can merge with different successors at different points of time. The most important point to be noted is that, the relationship between activities is independent of whether you want to have backward scheduling or forward scheduling.

However, in such situation, if you want only backward scheduling to take place without forward scheduling, you have to enable this in the last activity by updating the latest dates as earliest dates too, by selecting the "Latest Possible"option.

If this setting is done, I dont see any problem. Lemme know if you have any issues in understanding this.

[Former Member]

Hi Navaneetha

I need your expertise advise.  To simplify, I have 3 activities ID:  10, 20, & 30.  They are Linear FS relationship.  For some reason, if activity ID#20 is not returned, the system does not show the FS relationship arrow from 10 to 30.  Please advise.  Thanks.

[Former Member]

What do you mean by "ID#20 is not returned"?  Do you mean it is deleted?

[former_member183879]

Hi Mr. Bui,

There is definitely a problem in your relationship.

You have three activities 10, 20 and 30. 10 is the predecessor for 20 and 20 is the predecessor of 30. There is no relationship between 10 and 30. This is something you should remember.

If for some reason activity 20 is not returned, obviously 10 and 30 will not be linked by FS relationship and 10 will not be a predecessor for 30 as you are expecting.

First, I dont know why activity 20 will not come in certain circumstances. Is this managed by means of some dependencies at the activity level?

Anyway, if you want 10 and 30 also to be linked by FS relationship, you can enable that. However the relationship will be irrespective of the presence or absence of activity 20. In such case the relationship will appear as follows.

10 is linked to 20 in FS relationship as predecessor.

10 is linked to 30 in FS relationship as predecessor.

20 is linked to 30 in FS relationship as predecessor.

20 will have dependencies which will decide the scenarios for enabling or disabling 20 in the network.

Hope this is clear to you. If you have any qns, lemme know.

[Former Member]

You only schedule the relationship between packets of work (activities) that are necessary.  The scheduling algorithm will calculate float and critical path based on the activity relationships.  Don't forget you can place constraints on activities and the diffent type of relationships and off-sets.

[Former Member]

Hi,

I need your expertise advise.  To simplify, I have 3 activities ID:  10, 20, & 30.  They are Linear FS relationship.  For some reason, if activity ID#20 is not returned, the system does not show the FS relationship arrow from 10 to 30.  Please advise.  Thanks.

Message was edited by: Mohamed Rafi - Open a new thread.

[Former Member]

Hi,

I you are not maintaining relationships between activities; it simply means all activities can start in parallel.

To maintain relationships or not is purely based on requirement.

Regards,

Harsh.