As late as possible constraint

J
John Kelly 👤 Member for 14 years 10 months

Hi,

Currenlty carrying out a tidy up operation on a BAeline programme prior to a delay analysis.

My question is how would you deal with a set of activities that have no predecessor and have an 'As late as possible' constraint assigned to them??

Thanks in advance

 

John

S
Sivakumar G 👤 Member for 12 years 1 month

Dear sir

You can create a new tasks and apply base line for that task and then you have to give constriant as late as possible now we see the difference

M
Mike Testro 👤 Member for 20 years 5 months

Hi John

If the milestone is for the commencement of design then there must be a duration for design completion.

This should be expressed as a task bar and linked FS to the task or milestone that requires the design input.

Remove the lag and set the design task to ALAP.

You can then monitor progress on the design task.

Best regards

Mike Testro 

J
John Kelly 👤 Member for 14 years 10 months

Guys,

Thanks for taking the time to reply.

I agree with what you guys have said in that there is nothing wrong with ALAP constraints when used correctly, good example Gary on the M&E equipment.

The activities in question on my analysis are commencement of Design activities for various parts of the Project.  These activities have no Predecessor and the only reason i can assume for using ALAP on the commencement of Design activities is possibly due to lack of Design resource.

 

I have removed the ALAP constraints and linked the said activities to the NTP milestone with positive lag ensuring no change in dates etc, this means as i import progress to my baseline as i proceed with my Windows analysis that these activities will remain in the same date unless progressed. Should i have left the ALAP constraint and just linked to the NTP milestone with lag? i think by removing the ALAP milestone i will start getting some spurious results, ie said activites being identified as the cause of delay when i reality it isn't.

 

Thanks

G
Gary Whitehead 👤 Member for 17 years 2 months

Nohing wrong with using ALAP in the right circumstances, as Mike & Vladimir have said.

I would add though that just because an ALAP constraint is appropriate does not mean having no predecessor is, even if the predecessor is not (currently) driving the activity.

Eg delivery of M&E equipment to site may be on an ALAP, so you do not have it sitting around on site for months before the civils are completed to allow it to install. But you should still have a design/procurement predecessor chain.

Client free-issues may have a project design predecessor, or if not should at least be linked from contract award.

 

M
Mike Testro 👤 Member for 20 years 5 months

Hi John

Vladimir is right - use of ALAP tasks such as "Last Date for Power On" or "Employer Free Issue Material On Site" is the natural way to set a task that has no predecessor in the programme but depends on outside influences.

If an event delays such tasks the in a delay analysis I would insert a bar that represents the delay period immediately before the ALAP task and hold that with a Must Start On constraint - then reschedule.

I would then colour the delay event bright scarlet but you can't do that in P6.

Best regards

Mike Testro

V
Vladimir Liberzon 👤 Member for 25 years 4 months

Why?

If you plan JIT supplies, training before implementation, etc. ALAP is very useful, practical and natural.

N
Neil Curtis 👤 Member for 14 years 2 months

John,

I'd try to eliminate the ALAP contraints by talking to the relevant subject matter experts in the project team about the activities concerned, requesting that the SMEs define the predecessor activities so that finish-to-start logic can be used instead.

Neil

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