This is a good point that is being well taken into consideration. Our drop dead dates are only circulated internally. I do not provide our suppliers or subcontractors with float calcs or late starts. We give them our own due dates.
Member for
21 years 8 months
Member for21 years8 months
Submitted by Rafael Davila on Wed, 2018-07-18 11:51
Please be reminded that a Drop Dead Date that would be calculated as the latest date an activity can finish without affecting the start date of any of its successor activities not always is a good idea. If you give too much leeway all might be used by your suppliers, this can consume too much or all of available float.
Planning without contingency reserves is self defeating.
Success Driven Project Management Paper - We recommend to use optimistic schedule for setting tasks for project work force and manage project reserves. The schedule that is calculated backward from the target dates with most probable estimates of activity durations we call Critical schedule. The difference between start and finish dates in current and critical schedules we call start and finish time buffers (contingency reserves). The difference between activity (phase) cost that has defined probability to be met and optimistic cost of the same activity (phase) we call cost buffer.
Start Buffer = A = Diff_Days_Calen ( Start_CMP2 ; Start ; Calen ) - Returns the difference in days between two dates by the given calendar.
Member for
7 years 4 months
Member for7 years4 months
Submitted by G.P.Willikers on Mon, 2018-07-16 22:42
Thank you for your responses. I also created start and finish user defined fields called Fab LS and Fab LF, then used a Global change to populate them with the late finish / start dates generated by the "as late as possible" constraint. That allowed me to remove the constraint, but maintain the drop dead dates.
Thanks again!
Greg
Member for
21 years 8 months
Member for21 years8 months
Submitted by Rafael Davila on Sun, 2018-07-15 13:16
No way all conceivable parameters will be provided within your software but the software shall give you the tools [functions] to calculate dates based on your calendars.
Calculate the Free Float Finish using User Defined Field and [Global Change] simple formula available in your software. Just take a look at the formula, cannot be any easier.
To apply the constraint as late as possible to that activity is an option to consider if your software does not provide the functions required to make the calculations.
Good Luck
Member for
16 years 3 months
Member for16 years4 months
Submitted by Zoltan Palffy on Tue, 2018-07-10 14:54
Member for
21 years 8 monthsThen, I must agree with your
Then, I must agree with your approach.
Member for
7 years 4 monthsThis is a good point that is
This is a good point that is being well taken into consideration. Our drop dead dates are only circulated internally. I do not provide our suppliers or subcontractors with float calcs or late starts. We give them our own due dates.
Member for
21 years 8 monthsPlease be reminded that a
Please be reminded that a Drop Dead Date that would be calculated as the latest date an activity can finish without affecting the start date of any of its successor activities not always is a good idea. If you give too much leeway all might be used by your suppliers, this can consume too much or all of available float.
Planning without contingency reserves is self defeating.
Success Driven Project Management Paper - We recommend to use optimistic schedule for setting tasks for project work force and manage project reserves. The schedule that is calculated backward from the target dates with most probable estimates of activity durations we call Critical schedule. The difference between start and finish dates in current and critical schedules we call start and finish time buffers (contingency reserves). The difference between activity (phase) cost that has defined probability to be met and optimistic cost of the same activity (phase) we call cost buffer.
Start Buffer = A = Diff_Days_Calen ( Start_CMP2 ; Start ; Calen ) - Returns the difference in days between two dates by the given calendar.
Member for
7 years 4 monthsThank you for your
Thank you for your responses. I also created start and finish user defined fields called Fab LS and Fab LF, then used a Global change to populate them with the late finish / start dates generated by the "as late as possible" constraint. That allowed me to remove the constraint, but maintain the drop dead dates.
Thanks again!
Greg
Member for
21 years 8 monthsMore interesting can be the
More interesting can be the calculation of Drop Dead Dates for partial deliveries of Consumable Resources such as Bricks.
As you can see in this model after consumable resources [Bricks] are leveled deliveries free float is consumed but not all float.
Member for
21 years 8 monthsNo way all conceivable
No way all conceivable parameters will be provided within your software but the software shall give you the tools [functions] to calculate dates based on your calendars.
Calculate the Free Float Finish using User Defined Field and [Global Change] simple formula available in your software. Just take a look at the formula, cannot be any easier.
To apply the constraint as late as possible to that activity is an option to consider if your software does not provide the functions required to make the calculations.
Good Luck
Member for
16 years 3 monthsyes apply the constraint as
yes apply the constraint as late as possible to that activity