Open End Activity

Hi Abhishek

An open end activity is one that has no outgoing link.

It is bad planning practice as it makes any criticality meaningless.

Such activities can usually be detected because both free float and total float will be the same.

Best regards

Mike Testro

Open ended activities provide flexibility. For my opinion, this is useful when you are scheduling group of activities (or projects under a project group). With this you can allow for any logic that you may find practicable. Or I guess, this is what they call "soft logics".

By the way, I'm refering to the development of a schedule.

Is it bad practice Mike?

Hi Anoon

You cannot create a critical path using open end activities.

A programme without a critical path is worthless.

Best regards

Mike Testro

Abhishek,

An open ended activity means that the activity in question, has no eny relation with the end of the project. It can be finished anytime even after the sun exploding. Fortunataly or unfortunately developers noticed that this problem arise often, so when they start the backward calculation (that is the phase for calculating late activity times) they set a maximum value which is the project end.  This will result that their latest finish will be the end of the project.

What we teach, that all these activities has to be exemined carefully, because they are usually sign of a mising logic. (you simply forgot to define their successor)

Anyway the same thing when you have too many open started activities, but this occurs in a fewer case.

There are some rules which should be kept, so we teach that before going nto technical details always check the following:

• number of start activities (open started)  (indicates missing logic)
• number of finish activities (open ended) (indicates missing logic)
• number of start danglers (indicates missing logic)
• number of finish danglers (indicates missing logic)
• negative lags (always indicate incorrect logic, or opposite dependency)
• activity length versus project duration (if the length of the activity can be compared to the project duration than tracking will not be proper)
• are there maximal relations or not (the lack of them indicates missing logic)

If your network is  OK  from these points of view, you can go into details, so you can get a chemist if the network is about some medcine, but these basic checkings can be done on the basis of planning methodology.

There are other things that you have to check if you have costs, resources, etc. but this would be Off tpic.

Miklós

,

In the project there will not be any open ended activity.

Even these activities are not critical for the completion of the project , but these should be connected to the project completion date.

In the project there will not be any open ended activity.

Even these activities are not critical for the completion of the project , but these should be connected to the project completion date.

Open ended are considred also the activities that are linked together with a start to start relation. No matter how much you change the duration or the Finish date of the predecessor the succesor is not afetced.

Regards,

Nicos Pozatos. 

Practically, there will always be open-ended activities, but you can always provide artificial link (irrelevant for me) to close it.

Consider a project like a puzzle, where you group it part by part, and each part has its own end.

Nicos,

what you have mentioned are called dangling activites. (just type it into google)

There are start danglers (a start dangler has a predecessor but only into his end    e.g.FF, SF)

and finish danglers  (a finish dangler has a follower but only from its start   eg. SS, SF relations)

I think instead of open ended it would be more accurate to use the following two terms

finish activity, and finish dangler (or dangling) activity.  

An appearence of a finish or finish danglingr activity usually indicates a missing logic, which has to be add in order to make the whole logic complete.( see my previous mail what we check first)

Miklós

Anoon,

"Consider a project like a puzzle, where you group it part by part, and each part has its own end."

Check one of your plan, and check all your finish activities. Is that really true, that they do not have a follower?

do not forget it means (as there is no path from tthis activities to the end) that there is no any logical dependancy (direct or indirect)  between an activity like this and the project finish.

If the logic is direct then you can omit  of giving these relations, just because in the applications backward calculation is set on that way that late finish times cannot be greater than the project duration, This means that the programmers put a virtual FF0 relation from all the end activities to a virtual end node that represents the project duration.

The best is that you give all the relations if they are exist to make the logic as complete as it can be

last note: in case of infrastructural projects when they can be cut into snall pieces and these sectionscan be done independently more finish activities can arise when you schedule a high rise building.

Miklós

Miklos,

Something must follow, but still not determined (or not decided yet), that's why you can leave it open (provides flexibility).

Why don't you just make it endless? or you just want to retire?

Hi Anoon

An open ended activity provides uncertainty - not flexibility.

Something must follow and if it is still uncertain create a buffer task and call it Uncertainty Buffer and link it up FS.

Best regards

Mike Testro

Mike,

Good definition (uncertainty and not flexibility).

"Uncertainty Buffer" - I like it. It only proves that "nothing is certain in real life".